Least reliable engines: ranking by documented faults

Of the 165 engines we have analysed, the 1.2 PureTech has the highest risk index: 96/100 (very high risk), mainly because of “Oil-bath timing belt degradation”. They are followed by the OM651 (89) and the 2.0 Ingenium diésel (87).

Ordered by our risk index (0–100), which weighs the severity and frequency of each engine's documented faults. It compares only the engines we have analysed. How it is calculated

Reviewed on 2 November 2026How we work

Rank 1
1.2 PureTech
Peugeot, Citroën, DS, Opel, Fiat, Jeep, Alfa Romeo, Lancia and Toyota
Risk index
96
Very high risk
Worst severity
Critical severity
Main fault
Oil-bath timing belt degradation
7 documented faults · 7 serious
Versions to avoid
None with an «Avoid» verdict
Rank 2
OM651
Mercedes-Benz and Infiniti
Risk index
89
Very high risk
Worst severity
Critical severity
Main fault
Timing chain stretch and tensioner failure
6 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 3
2.0 Ingenium diésel
Land Rover and Jaguar
Risk index
87
Very high risk
Worst severity
Critical severity
Main fault
Timing chain stretch
5 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 3
BMW N47
BMW and MINI
Risk index
87
Very high risk
Worst severity
Critical severity
Main fault
Rear timing chain stretch and breakage
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 3
BMW N57
BMW
Risk index
87
Very high risk
Worst severity
Critical severity
Main fault
EGR cooler leaks with risk of engine fire
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 6
1.2 and 1.4 TSI
Volkswagen, Seat, Škoda and Audi
Risk index
84
Very high risk
Worst severity
Critical severity
Main fault
Timing chain stretch and tensioner failure (EA111)
5 documented faults · 3 serious
Versions to avoid
- 1.4 TSI twincharger 140-185 hp (EA111, BMY/BLG/CAVD/CAVE…, 2006-2012)
Rank 7
BMW M47
BMW, Rover and Land Rover
Risk index
79
Very high risk
Worst severity
Critical severity
Main fault
Intake swirl flap breakage (swirl flaps)
6 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 8
1.5 BlueHDi
Peugeot, Citroën, DS, Opel, Toyota and Fiat
Risk index
77
Very high risk
Worst severity
Critical severity
Main fault
Wear and breakage of the 7 mm chain between the camshafts
5 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 8
2.0/2.2 D-4D
Toyota and Lexus
Risk index
77
Very high risk
Worst severity
Critical severity
Main fault
Warped cylinder head gasket and oil consumption on the 2.2 D-4D
4 documented faults · 1 serious
Versions to avoid
- 2.2 D-4D (2AD-FTV, 136-150 hp, 2005-2015)
- 2.2 D-4D D-CAT (2AD-FHV, 174-177 hp, 2005-2015)
Rank 10
BMW B47
BMW and MINI
Risk index
73
High risk
Worst severity
Critical severity
Main fault
EGR cooler leaks with risk of engine fire
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 11
OM642
Mercedes-Benz, Jeep, Chrysler, Dodge and Freightliner
Risk index
72
High risk
Worst severity
Critical severity
Main fault
Broken swirl flaps in the intake manifold
5 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 12
1.0 EcoBoost
Ford
Risk index
71
High risk
Worst severity
Critical severity
Main fault
Degradation of the timing belt running in oil
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 12
1.6 HDi
Peugeot, Citroën, DS, Ford, Volvo, Mazda, MINI, Opel and Toyota
Risk index
71
High risk
Worst severity
High severity
Main fault
Turbo failure through lack of lubrication (carbon deposits and union filter)
7 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 14
1.6 CRDi
Hyundai and Kia
Risk index
70
High risk
Worst severity
Critical severity
Main fault
MHSG belt tensioner and crankshaft pulley failure (48V mild hybrid)
6 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 15
1.9 dCi
Renault, Nissan and Volvo
Risk index
67
High risk
Worst severity
Critical severity
Main fault
Seizure and wear of the big-end bearings
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 16
1.9 TDI
Volkswagen, Seat, Škoda and Audi
Risk index
66
High risk
Worst severity
Critical severity
Main fault
Big-end bearing failure
6 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 17
1.3 Multijet
Fiat, Lancia, Alfa Romeo, Opel, Suzuki and Ford
Risk index
64
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch and tensioner failure
5 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 17
MZR-CD
Mazda
Risk index
64
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch on the 2.2 MZR-CD
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 17
D4/D5
Volvo
Risk index
64
High risk
Worst severity
Critical severity
Main fault
Auxiliary belt breakage that takes the timing belt with it (5-cylinder)
6 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 17
1.6 THP
Peugeot, Citroën, DS and MINI
Risk index
64
High risk
Worst severity
Critical severity
Main fault
Timing chain and tensioner stretch (turbo versions, before 2012)
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 21
1.5 dCi
Renault, Dacia, Nissan, Mercedes-Benz, Infiniti and Suzuki
Risk index
63
High risk
Worst severity
Critical severity
Main fault
Wear and seizure of the big-end bearings
8 documented faults · 4 serious
Versions to avoid
- 1.5 dCi Euro 3 (65, 80/82 and 100 hp, 2001-2005)
Rank 21
OM654
Mercedes-Benz
Risk index
63
High risk
Worst severity
Critical severity
Main fault
Timing chain wear or breakage (2016 to 2021 units)
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 21
BMW M57
BMW, Land Rover and Opel
Risk index
63
High risk
Worst severity
Critical severity
Main fault
Broken intake swirl flaps
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 21
BMW N20
BMW
Risk index
63
High risk
Worst severity
Critical severity
Main fault
Timing chain guide and tensioner wear (2011-2015)
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 21
2.3 MZR DISI Turbo
Mazda
Risk index
63
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch and VVT actuator failure on the 2.3 DISI Turbo
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 26
2.0 and 2.5 Hybrid
Toyota and Lexus
Risk index
61
High risk
Worst severity
Critical severity
Main fault
Low-pressure fuel pump failure: loss of power and fire risk
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
Subaru bóxer
Subaru
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Bearing wear and crankshaft failure on the EE20 diesel
7 documented faults · 3 serious
Versions to avoid
- 2.0 D 147-150 hp Euro 4 (EE20, 2008-2010)
Rank 27
1.6 EcoBoost
Ford and Volvo
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Cracked cylinder head from overheating, with fire risk
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
2.5 dCi YD25
Nissan
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Timing chain wear and failure
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
1.0 PureTech
Peugeot and Citroën
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Excessive oil consumption through the piston rings
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
1.5 / 2.0 EcoBlue
Ford
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Degradation of the wet timing belt (2.0 EcoBlue)
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
1.0/1.2/1.4 Ecotec
Opel and Vauxhall
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch and breakage
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
BMW N43/N46
BMW
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Wear and breakage of the timing chain guides
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 27
M271
Mercedes-Benz
Risk index
59
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch and wear of the camshaft sprockets
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 35
1.2 12V
Volkswagen, Seat and Škoda
Risk index
57
High risk
Worst severity
Critical severity
Main fault
Timing chain stretch and tensioner wear
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 35
BMW N13
BMW
Risk index
57
High risk
Worst severity
Critical severity
Main fault
Timing chain and tensioner wear
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 35
M272/M273
Mercedes-Benz
Risk index
57
High risk
Worst severity
Critical severity
Main fault
Wear of the balance shaft gear and the timing sprockets
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 38
Porsche V8 and V6 (Cayenne and Panamera)
Porsche
Risk index
55
High risk
Worst severity
Critical severity
Main fault
Cracked plastic coolant pipes on the Cayenne V8
7 documented faults · 5 serious
Versions to avoid
None with an «Avoid» verdict
Rank 38
Skyactiv-D
Mazda
Risk index
55
High risk
Worst severity
Critical severity
Main fault
Oil dilution with diesel during DPF regenerations
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 38
1.0 / 1.5 VTEC Turbo
Honda
Risk index
55
High risk
Worst severity
Critical severity
Main fault
Engine failure caused by the wet timing belt
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 38
2.0 HDi
Peugeot, Citroën, Ford, Volvo and Toyota
Risk index
55
High risk
Worst severity
High severity
Main fault
Variable-geometry turbo failures (actuator, sensors and clogging)
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 42
BMW N62 / N63
BMW
Risk index
54
High risk
Worst severity
Critical severity
Main fault
N63 oil consumption from worn valve stem seals
6 documented faults · 3 serious
Versions to avoid
- N63B44O0 4.4 twin-turbo 408 hp (2008-2014)
Rank 42
1.6 / 2.2 i-DTEC
Honda
Risk index
54
High risk
Worst severity
Critical severity
Main fault
Turbocharger failure
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 42
2.0 TSI / TFSI
Volkswagen, Audi, Seat, Cupra and Škoda
Risk index
54
High risk
Worst severity
Critical severity
Main fault
High oil consumption
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 42
1.2 TCe
Renault, Dacia, Nissan and Mercedes-Benz
Risk index
54
High risk
Worst severity
Critical severity
Main fault
Excessive oil consumption and engine failure
2 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 42
1.33 Dual VVT-i
Toyota
Risk index
54
High risk
Worst severity
Critical severity
Main fault
Excessive oil consumption from piston wear
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 42
BMW M54
BMW
Risk index
54
High risk
Worst severity
High severity
Main fault
Thermostat and water pump failure
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
3.0 TDI V6
Audi, Volkswagen and Porsche
Risk index
52
High risk
Worst severity
Critical severity
Main fault
Failing water pump and cooling system leaks
7 documented faults · 4 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
2.2/2.5 dCi
Nissan
Risk index
52
High risk
Worst severity
Critical severity
Main fault
Premature turbo and intercooler failure
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
1.6 and 2.0 MultiJet II
Fiat, Jeep and Alfa Romeo
Risk index
52
High risk
Worst severity
Critical severity
Main fault
Saturated diesel particulate filter (DPF) from incomplete regenerations
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
2.0 dCi
Renault, Nissan and Opel
Risk index
52
High risk
Worst severity
Critical severity
Main fault
Premature turbocharger failure
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
1.4/1.6 VTi
Peugeot, Citroën, DS and MINI
Risk index
52
High risk
Worst severity
Critical severity
Main fault
Fragile water pump (and expansion tank or heat exchanger, depending on displacement)
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 48
2.2 i-CTDi
Honda
Risk index
52
High risk
Worst severity
High severity
Main fault
Turbocharger failure
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 54
1.8 Hybrid
Toyota and Lexus
Risk index
50
High risk
Worst severity
Critical severity
Main fault
Brake actuator failure (hard pedal, loss of assistance)
6 documented faults · 5 serious
Versions to avoid
None with an «Avoid» verdict
Rank 55
0.9 TCe
Renault, Dacia and Smart
Risk index
49
Moderate risk
Worst severity
Critical severity
Main fault
Coolant leak at the thermostat housing
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
2.0 TDI
Volkswagen, Seat, Škoda and Audi
Risk index
48
Moderate risk
Worst severity
Critical severity
Main fault
Oil pump failure on the pumpe-düse 2.0 TDI
8 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.8 TDCi
Ford
Risk index
48
Moderate risk
Worst severity
Critical severity
Main fault
Breakage of the timing belt or of the high-pressure pump's belt (running in oil)
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.4 and 1.6 8v
Renault and Dacia
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
LPG tank corrosion
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
2.2 HDi
Peugeot, Citroën, Ford and Land Rover
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
DPF clogging with additive, especially on the 128-138 hp version
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.4 D-4D
Toyota and MINI
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
Turbocharger failure
6 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.9 JTD/Multijet and 2.4 JTD
Fiat, Alfa Romeo, Opel, Saab and Suzuki
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
Intake manifold flap failure (swirl effect)
6 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.2 / 1.4 / 1.8 i-VTEC
Honda
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
i-SHIFT automated gearbox actuator failure
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.6 dCi
Renault, Nissan, Opel, Fiat and Mercedes-Benz
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
Premature turbocharger failure or breakage
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
BMW N52 / N53
BMW
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
N53 piezoelectric injector failure
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
BMW N54/N55
BMW
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
High-pressure fuel pump (HPFP) failure
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 56
1.4 T-Jet
Fiat, Abarth, Alfa Romeo, Lancia and Jeep
Risk index
48
Moderate risk
Worst severity
High severity
Main fault
Premature turbocharger failure or wear
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 67
2.2 dCi and 3.0 dCi V6
Renault
Risk index
46
Moderate risk
Worst severity
Critical severity
Main fault
3.0 dCi V6 overheating and expansion tank failures
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 67
TDV6 / SDV6
Land Rover, Jaguar, Peugeot and Citroën
Risk index
46
Moderate risk
Worst severity
Critical severity
Main fault
Crankshaft breakage and spinning main bearing shells
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 67
1.8/2.2 DI-D
Mitsubishi
Risk index
46
Moderate risk
Worst severity
High severity
Main fault
Clogged particulate filter and oil dilution
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 67
Rover K-Series
Rover, MG, Land Rover and Lotus
Risk index
46
Moderate risk
Worst severity
High severity
Main fault
Head gasket failure
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 67
2.2 CDI (OM646)
Mercedes-Benz and Chrysler
Risk index
46
Moderate risk
Worst severity
High severity
Main fault
Injector seal leak with carbonisation around the seat
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 72
2.5 TDI R5
Volkswagen
Risk index
45
Moderate risk
Worst severity
Critical severity
Main fault
Plasma coating flaking off the cylinders
5 documented faults · 2 serious
Versions to avoid
- 2.5 TDI 130 and 174 hp (AXD, AXE, 2003-2006)
Rank 72
1.4 Turbo
Opel and Vauxhall
Risk index
45
Moderate risk
Worst severity
Critical severity
Main fault
Early engine failure from a cracked piston
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 72
1.2 TDI
Volkswagen, Seat and Škoda
Risk index
45
Moderate risk
Worst severity
High severity
Main fault
Manipulated emissions software (dieselgate) and the subsequent update
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 72
1.6 TDI
Volkswagen, Seat, Škoda and Audi
Risk index
45
Moderate risk
Worst severity
High severity
Main fault
Manipulated emissions software (dieselgate) and air flow stabiliser
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 72
2.0 BlueHDi
Peugeot, Citroën, DS and Opel
Risk index
45
Moderate risk
Worst severity
High severity
Main fault
AdBlue (SCR) tank and pump failure
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 72
1.4 and 1.6 16v
Renault and Dacia
Risk index
45
Moderate risk
Worst severity
High severity
Main fault
Ignition coil failure
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 78
1.5 Hybrid
Toyota and Mazda
Risk index
44
Moderate risk
Worst severity
Critical severity
Main fault
Hybrid system shutdown without fail-safe mode (loss of drive)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
1.6 GDI / T-GDI
Hyundai and Kia
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Low-speed pre-ignition and connecting rod damage in the 1.6 T-GDI (documented in the US)
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
2.2 / 2.4 / 3.2 TDCi (Puma)
Ford, Peugeot, Citroën and Land Rover
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Oil pump failure on the Ranger's 2.2 TDCi
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
1.5 EcoBoost
Ford
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Coolant loss through a microcrack in the engine block (4-cylinder 1.5)
2 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
1.6 GDi híbrido (Kappa)
Hyundai and Kia
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Main relay of the power relay assembly (overheating and fire risk)
2 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
M270/M274
Mercedes-Benz
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Camshaft breakage due to a defective weld (2015 units)
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
2.0 and 2.2 VCDi
Chevrolet
Risk index
43
Moderate risk
Worst severity
Critical severity
Main fault
Sump cover fire risk from DPF fault (2011–2015 Captiva diesel)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
1.4 HDi
Peugeot, Citroën, Ford, Mazda and Toyota
Risk index
43
Moderate risk
Worst severity
High severity
Main fault
Injectors that lose their seal and let diesel escape
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 79
Drive-E gasolina
Volvo
Risk index
43
Moderate risk
Worst severity
High severity
Main fault
High oil consumption that can damage the turbo
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 87
1.0 TCe / SCe
Renault, Dacia and Nissan
Risk index
41
Moderate risk
Worst severity
Critical severity
Main fault
LPG (ECO-G) system faults and tank recall
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 87
MZR gasolina
Mazda
Risk index
41
Moderate risk
Worst severity
Critical severity
Main fault
Big-end bearing damage in the 2.3 MZR, with isolated cases in the 1.8 and 2.0
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 87
VW 2.0 TFSI EA113
Volkswagen, Audi, SEAT and Škoda
Risk index
41
Moderate risk
Worst severity
High severity
Main fault
Wear of the high-pressure pump cam follower
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 90
OM656
Mercedes-Benz
Risk index
39
Moderate risk
Worst severity
Critical severity
Main fault
Leak in the vacuum-driven coolant pump (fire risk)
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 90
D5 5 cilindros
Volvo
Risk index
39
Moderate risk
Worst severity
Critical severity
Main fault
Auxiliary belt breakage that takes the timing with it
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
2.0 CDTI
Opel and Vauxhall
Risk index
38
Moderate risk
Worst severity
Critical severity
Main fault
Turbocharger wear or failure
6 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
2.0 / 2.4 GDI and T-GDI (Theta II)
Hyundai and Kia
Risk index
38
Moderate risk
Worst severity
Critical severity
Main fault
Premature connecting rod bearing wear
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
1.7 CRDi
Hyundai and Kia
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
Injectors that lose calibration with mileage
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
1.4 TDI
Volkswagen, Seat, Škoda and Audi
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
Timing belt and water pump
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
2.0 and 2.2 CRDi
Hyundai and Kia
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
High oil consumption from worn piston rings and valve guides (2.2 CRDi)
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
2.0 DTI and 2.2 DTI
Opel and Vauxhall
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
VP44 injection pump and air mass meter failure
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
BMW B58
BMW and Toyota
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
Failure of the oil pump with a plastic rotor housing
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 92
M111
Mercedes-Benz
Risk index
38
Moderate risk
Worst severity
Medium severity
Main fault
Head gasket failure with coolant loss
5 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.7 CDTI
Opel, Vauxhall and Honda
Risk index
36
Moderate risk
Worst severity
Critical severity
Main fault
Dual-mass flywheel and clutch wear
5 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
Volvo 5 cilindros gasolina
Volvo and Ford
Risk index
36
Moderate risk
Worst severity
Critical severity
Main fault
Front camshaft seal leak wetting the timing belt
7 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
2.0 CDI (OM640)
Mercedes-Benz
Risk index
36
Moderate risk
Worst severity
Critical severity
Main fault
Costly failure of the Autotronic (CVT) automatic gearbox
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.5 VC-Turbo e-Power
Nissan
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Safe mode due to battery controller calibration (loss of propulsion)
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.3 TCe
Renault, Dacia, Nissan and Mercedes-Benz
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Turbo actuator (wastegate) fault
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
Audi 3.0 TFSI V6
Audi, Porsche and Volkswagen
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Timing chain stretch and tensioner wear
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
2.2 JTDm Multijet II
Alfa Romeo
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Diesel leak from the fuel filter gasket
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.0 T-GDI
Hyundai and Kia
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Wear and progressive failure of the turbocharger
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.4 16v and 1.6 FSI
Volkswagen, Seat, Škoda and Audi
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Timing belt and water pump
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.2 16v
Renault and Dacia
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Damaged head gasket and coolant loss
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.4 and 1.6 TU3/TU5
Peugeot and Citroën
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Head gasket damaged after overheating
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.1 and 1.4 CRDi
Hyundai and Kia
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Turbocharger wear and loss of performance
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 100
1.6 CDTI
Opel, Vauxhall, Chevrolet and GMC
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Noise and early wear of the timing chain and its tensioner
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 113
1.0 VVT-i
Toyota, Citroën and Peugeot
Risk index
35
Moderate risk
Worst severity
High severity
Main fault
Premature clutch wear
6 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 114
Honda e:HEV / i-MMD
Honda
Risk index
34
Moderate risk
Worst severity
High severity
Main fault
Cracked high-pressure fuel pump (Honda campaign 6YP)
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 114
2.0 FSI
Volkswagen, Audi, Seat and Škoda
Risk index
34
Moderate risk
Worst severity
Medium severity
Main fault
Carbon build-up on the intake valves
3 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
2.2 TD4 / SD4
Land Rover and Jaguar
Risk index
32
Moderate risk
Worst severity
Critical severity
Main fault
Coolant leak from the EGR valve cooler
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
2.3 dCi (M9T)
Renault, Opel and Nissan
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Clogged or broken EGR valve damaging the turbo
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
2.0 CRDi (D4EA)
Hyundai and Kia
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Wear and loss of performance of the variable-geometry turbo
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
E-Tech Híbrido
Renault and Dacia
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Multi-mode gearbox failure (risk of breakage)
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
1.8 TCe
Alpine and Renault
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
A110 oil pressure solenoid valve sticking in 2018–2019 cars
2 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
0.9 TwinAir and 1.0/1.3 FireFly
Fiat, Jeep, Lancia and Alfa Romeo
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Early turbocharger failure (0.9 TwinAir)
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
1.8 T 20v
Volkswagen, Audi, Seat and Škoda
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Turbo wear and oil consumption
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
M112 / M113
Mercedes-Benz
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Crankshaft pulley (vibration damper) failure
5 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
2.0 and 2.4 VVT-i
Toyota
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Cylinder head bolt threads in the 2AZ-FE block
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
VM Motori 2.8 and 3.0 CRD
Jeep, Chrysler, Lancia, Dodge and Maserati
Risk index
32
Moderate risk
Worst severity
High severity
Main fault
Loss of the crankshaft signal that stalls the engine (Grand Cherokee 3.0 V6 CRD)
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 116
1.2 Turbo
Toyota
Risk index
32
Moderate risk
Worst severity
Medium severity
Main fault
Carbon build-up on the intake valves
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 127
1.4, 1.6 and 1.8 VVT-i
Toyota
Risk index
30
Moderate risk
Worst severity
Medium severity
Main fault
High oil consumption due to piston ring wear
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 128
1.6 e-XDi160
SsangYong and KGM
Risk index
29
Moderate risk
Worst severity
Critical severity
Main fault
Fuel line leaks (2018–2021 recalls)
1 documented fault · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 128
M264/M254
Mercedes-Benz
Risk index
29
Moderate risk
Worst severity
High severity
Main fault
Poorly tightened 48 V earth wiring in the mild-hybrid system (fire risk)
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 128
Smartstream 1.6 T-GDi
Hyundai and Kia
Risk index
29
Moderate risk
Worst severity
High severity
Main fault
Brake servo vacuum pump damaged on start-up (Tucson 1.6 T-GDi 48V and Sportage, 2022-2023)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 131
1.3, 1.5 and 1.6 gasolina (serie M)
Suzuki and Fiat
Risk index
27
Moderate risk
Worst severity
Medium severity
Main fault
Faulty catalytic converter and lambda sensors on the 2005-2010 Swift (engine warning light)
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 132
2.3 MultiJet
Fiat and Iveco
Risk index
25
Moderate risk
Worst severity
Critical severity
Main fault
Camshaft breakage due to a manufacturing defect (Ducato, 2016-2017)
6 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 132
2.0 16v F4R and F4RT
Renault
Risk index
25
Moderate risk
Worst severity
Critical severity
Main fault
Timing belt failure due to overdue maintenance
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 132
Skyactiv-G
Mazda
Risk index
25
Moderate risk
Worst severity
Medium severity
Main fault
Intake shut-off valve software issue and engine stalling
5 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 132
1.25/1.4/1.6 Ti-VCT
Ford
Risk index
25
Moderate risk
Worst severity
Medium severity
Main fault
Ti-VCT actuator or solenoid valve failure on the early units
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 132
2.4 JTD / JTDm Multijet
Alfa Romeo, Lancia and Fiat
Risk index
25
Moderate risk
Worst severity
Medium severity
Main fault
Intake manifold flap failure (swirl flaps)
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 137
Mitsubishi PHEV
Mitsubishi
Risk index
24
Low risk
Worst severity
High severity
Main fault
Loss of traction battery (high-voltage) capacity
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 137
BMW B48 / B38
BMW and MINI
Risk index
24
Low risk
Worst severity
High severity
Main fault
Deterioration of hoses and seals in the cooling circuit, with coolant loss
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
2.0 MR20DE / 2.5 QR25DE
Nissan and Renault
Risk index
23
Low risk
Worst severity
Critical severity
Main fault
CVT gearbox oil cooler leak on the Qashqai I 2.0
4 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
2.0 / 2.4 i-VTEC
Honda
Risk index
23
Low risk
Worst severity
High severity
Main fault
Camshaft wear and pitting on the 2.0 K20 (Accord VII, CR-V II, Civic)
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.0 TSI / 1.5 TSI
Volkswagen, Seat, Cupra, Škoda and Audi
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Coolant leaks from the water pump and thermostat module
5 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.2 Dualjet and 1.2 VVT
Suzuki
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Clutch: premature wear and clutch cable anchor failure
5 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.0 SCe (B4D)
Renault and Dacia
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Clutch that slips or judders, especially when cold
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.6 and 1.8 Ecotec 16v
Opel and Vauxhall
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Oil and coolant leak or mixing via the oil cooler (1.8)
3 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.6 DIG-T
Nissan
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Timing chain wear and noise
3 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 139
1.0 / 1.25 MPi
Hyundai and Kia
Risk index
23
Low risk
Worst severity
Medium severity
Main fault
Premature clutch wear and slipping
2 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 147
BMW B57
BMW
Risk index
22
Low risk
Worst severity
High severity
Main fault
AdBlue/SCR system fault (NOx sensors, heater and pump)
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 148
e-Skyactiv D 3.3
Mazda
Risk index
21
Low risk
Worst severity
High severity
Main fault
Stalling and restart failures due to control unit software
2 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 148
Honda IMA híbrido
Honda
Risk index
21
Low risk
Worst severity
High severity
Main fault
High-voltage IMA battery degradation and IMA warning light on
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
BMW B38 / B37
BMW and MINI
Risk index
20
Low risk
Worst severity
Critical severity
Main fault
B38 crankshaft thrust bearing failure (units before April 2015)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
M260
Mercedes-Benz
Risk index
20
Low risk
Worst severity
High severity
Main fault
Possible leak in the turbo oil line (2019-2020 recall)
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
1.2 8v Fire
Fiat, Lancia and Ford
Risk index
20
Low risk
Worst severity
Medium severity
Main fault
Sensor failures: lambda sensor and crankshaft position sensor (TDC)
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
1.6 16v HR16DE / H4M
Nissan, Renault and Dacia
Risk index
20
Low risk
Worst severity
Medium severity
Main fault
Premature clutch and flywheel wear
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
2.4 / 2.8 D-4D (GD)
Toyota
Risk index
20
Low risk
Worst severity
Medium severity
Main fault
Blocked particulate filter (DPF) due to incomplete regenerations
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 150
1.6 Dual VVT-i
Toyota
Risk index
20
Low risk
Worst severity
Medium severity
Main fault
Water pump leak
3 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 156
1.0 MPI
Volkswagen, Seat and Škoda
Risk index
19
Low risk
Worst severity
Medium severity
Main fault
Cooling system fault with engine light and vibrations
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 157
1.0 T3 and 1.3 T4 FireFly Turbo
Jeep, Fiat and Alfa Romeo
Risk index
18
Low risk
Worst severity
Medium severity
Main fault
Oil consumption and premature turbo wear on the 1.0 T3 and 1.3 T4
2 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 158
MIVEC gasolina
Mitsubishi, Smart, Peugeot and Citroën
Risk index
15
Low risk
Worst severity
High severity
Main fault
Cracked fuel pump cover with fuel leak on the Colt
4 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 159
2.2 MultiJet / BlueHDi (Stellantis)
Fiat, Peugeot, Citroën, Opel and Toyota
Risk index
14
Low risk
Worst severity
High severity
Main fault
Unvulcanised fuel return pipe: fuel leak and fire risk
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 159
1.2 HR12DE and 1.2 DIG-S (HR12DDR)
Nissan
Risk index
14
Low risk
Worst severity
Medium severity
Main fault
Short-circuited ignition coil: the engine stalls and will not restart
1 documented fault · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 159
1.5 K15B (Jimny)
Suzuki
Risk index
14
Low risk
Worst severity
Medium severity
Main fault
Fuel pump with resin impeller that swells (recall)
1 documented fault · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 159
2.0 and 2.2 16v EW10/EW12
Peugeot and Citroën
Risk index
14
Low risk
Worst severity
Medium severity
Main fault
Faulty ignition coils
1 documented fault · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 163
2.0 and 3.0 Ingenium gasolina
Land Rover and Jaguar
Risk index
7
Low risk
Worst severity
Medium severity
Main fault
Timing chain and VCT unit noise on the 2.0 petrol
1 documented fault · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 163
1.5 VTi-TECH / T-GDI
MG
Risk index
7
Low risk
Worst severity
Low severity
Main fault
Jerky or harsh automatic gearbox shifts when cold or at low speed (MG HS)
2 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict
Rank 165
1.0 and 1.4 Boosterjet
Suzuki
Risk index
6
Low risk
Worst severity
Low severity
Main fault
Timing chain: no documented pattern of failures
4 documented faults · 0 serious
Versions to avoid
None with an «Avoid» verdict

Gearboxes analysed

Gearboxes are rated with the same index, but listed separately: they do not compete with the engines.

Rank 1
PowerShift
Ford
Risk index
72
High risk
Worst severity
High severity
Main fault
Juddering, hesitation and slipping of the dry clutch (DPS6)
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 2
Multitronic
Audi and Seat
Risk index
64
High risk
Worst severity
Critical severity
Main fault
Wear of the variator chain and cones
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 3
DSG7 DQ200
Volkswagen, Seat, Škoda and Audi
Risk index
59
High risk
Worst severity
High severity
Main fault
Mechatronic unit failure: pressure accumulator, pump and cracked housing
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 4
7DCT
Hyundai and Kia
Risk index
46
Moderate risk
Worst severity
Critical severity
Main fault
Jerking, hesitation and mechatronic faults at low speed
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 4
ZF 6HP
BMW, Audi, Land Rover and Jaguar
Risk index
46
Moderate risk
Worst severity
High severity
Main fault
Valve body and mechatronic failure: erratic shifts or a locked-up gearbox
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 6
7G-Tronic / 9G-Tronic
Mercedes-Benz
Risk index
44
Moderate risk
Worst severity
High severity
Main fault
Conductor plate and speed sensor failure (limp mode)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 7
EDC
Renault and Dacia
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
EDC gearbox overheating and safety neutral
4 documented faults · 3 serious
Versions to avoid
None with an «Avoid» verdict
Rank 7
CVT Xtronic
Nissan and Renault
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
Oil leaks and internal wear that can force gearbox replacement
3 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 7
EAT6/EAT8
Peugeot, Citroën, DS and Opel
Risk index
38
Moderate risk
Worst severity
High severity
Main fault
Valve body failure leading to immobilisation or gearbox replacement
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 10
7G-DCT
Mercedes-Benz
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Incorrect oil level in the 7G-DCT: December 2020 campaign
5 documented faults · 2 serious
Versions to avoid
None with an «Avoid» verdict
Rank 10
DSG6 DQ250
Volkswagen, Seat, Škoda and Audi
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Mechatronic unit failure: solenoid valves and temperature sensor
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 10
DSG7 DQ381/DQ500
Volkswagen, Seat and Škoda
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Mechatronic unit and oil pump failure
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 10
ZF 8HP
BMW, Audi, Jaguar, Land Rover, Alfa Romeo and Jeep
Risk index
36
Moderate risk
Worst severity
High severity
Main fault
Mechatronic failure as the gearbox ages (sometimes with reverse)
3 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 14
Dualogic
Fiat and Lancia
Risk index
29
Moderate risk
Worst severity
High severity
Main fault
Actuator or hydraulic pressure fault: the gearbox drops into neutral on its own or refuses gears
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 15
AL4 / DP0
Peugeot, Citroën and Renault
Risk index
25
Moderate risk
Worst severity
High severity
Main fault
Degraded oil: harsh shifts, slipping and overheating
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict
Rank 16
09G (Aisin)
Volkswagen, Audi, Seat and Škoda
Risk index
14
Low risk
Worst severity
High severity
Main fault
Total gearbox failure at low mileage, documented in an isolated case
2 documented faults · 1 serious
Versions to avoid
None with an «Avoid» verdict

Torn between two of them? Compare two engines or see the most reliable engines.

How the risk index is calculated

1
Each documented fault receives a score: severity × frequency. Severity ranges from 1 (low) to 4 (critical) and frequency from 1 (rare) to 4 (very frequent). The maximum per fault is 16.
2
The three highest-scoring faults are taken. The first counts in full, the second counts half and the third a quarter. This way, an engine does not come out worse just because it has more minor faults documented.
3
The result is expressed from 0 to 100. A 100 would be three critical-severity faults that are very frequent.

0–24: low risk
25–49: moderate risk
50–74: high risk
75–100: very high risk

What it is not. It is not a statistic of faults per car sold, nor a prediction for a particular car: it summarises the faults documented in the sources we cite on each page. It only compares the engines we have analysed so far (165): an engine not appearing says nothing about its reliability.

Full methodology