1.0 EcoBoost vs 1.8 T 20v: which engine is more reliable?

According to our risk index, the 1.8 T 20v carries less risk than the 1.0 EcoBoost: 32/100 (moderate risk) versus 71/100 (high risk). The 1.0 EcoBoost has 3 documented serious faults, the main one being «Degradation of the timing belt running in oil»; the 1.8 T 20v has 1 documented serious fault, the main one being «Turbo wear and oil consumption».

Risk index

1.0 EcoBoost

High risk · 3 serious faults

Risk index

1.8 T 20v

Moderate risk · 1 serious fault

Lower risk

The index (0–100) weights the severity and frequency of the three most serious documented faults. How it is calculated

Reviewed on 27 September 202621 sources How we work

Is the 1.0 EcoBoost reliable?

It is a turbocharged direct-injection three-cylinder that has won Engine of the Year several times, but it has two very well-documented weak points: two belts running in oil (timing and oil pump) that can disintegrate and seize the engine, and cases of coolant leaks and overheating in early units. It is best bought with a service history and the belts checked or replaced on time.^[1][2][3][4]

See the 4 of the 1.0 EcoBoost faults

Is the 1.8 T 20v reliable?

With up-to-date maintenance, the 20-valve 1.8T has a reputation as a powerful, durable engine for its time, but owner reports document recurring faults: ignition coils (especially on 2001 to 2003 units), water pump and air mass meter, and less often the turbo -sometimes linked to growing oil consumption- and the timing chain tensioner.^{[5][6][7][8][9][10]}

See the 5 of the 1.8 T 20v faults

Side-by-side comparison

Comparison of 1.0 EcoBoost and 1.8 T 20v
Item	1.0 EcoBoost	1.8 T 20v
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	999 cm³	1,781 cm³
Timing	Wet belt (belt-in-oil)	Timing belt (dry)
Power	100–155 hp	150–225 hp
Production	since 2012^{[1][11][12][13]}	1996–2006^{[14][15][16][17]}
Reliability
Risk index (what is it?)	71High risk	32Moderate risk
Documented faults	4	5
Of high or critical severity	3	1
Worst severity	Critical severity	High severity
Main faults	Critical severity: Degradation of the timing belt running in oil Critical severity: Oil pump belt and tensioner failure Critical severity: Coolant leaks and overheating from the turbo hose	High severity: Turbo wear and oil consumption Medium severity: Water pump failure Medium severity: Timing chain tensioner noise and wear
Most expensive documented repair	up to €1,200Degradation of the timing belt running in oilPublished figure^[2]	No reliable data
Which versions to buy
BuyRecommended versions	None	None
With cautionVersions to be cautious about	1.0 EcoBoost 100/125 (Fox, 2012-2017)^[2][3][18] 1.0 EcoBoost 100/125/140 with cylinder deactivation (from ~2017)^[19][20] 1.0 EcoBoost Hybrid 48V mild hybrid (125/155 hp, from 2019)^[1][21]	1.8 T 20v 150 hp (AEB/AGU/ARZ/AUM, 1996-2005)^[6][10] 1.8 T 20v 180 hp (AUQ, 1998-2006)^[7][8] 1.8 T 20v 225 hp quattro (BAM, 1999-2006)^[8]
AvoidVersions to avoid	None	None

Severity of each fault: green, low; amber, medium; red, high; dark red, critical. How we rate them

Cars that each one is fitted to

1.0 EcoBoost

See the 11 models with the 1.0 EcoBoost

1.8 T 20v

See the 11 models with the 1.8 T 20v

Other comparisons

With the 1.0 EcoBoost

With the 1.8 T 20v

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Sources

Every fact on this page links to its source. If you find an error, let us know.

Ford EcoBoost engineWikipedia · Other source · consulted 26 September 2026
Alerta Ford: la correa de distribución del 1.0 EcoBoost puede romper el motor y la NHTSA ya investigaMotor16 · Motoring press · consulted 26 September 2026 · in Spanish
Los Ford 1.0 EcoBoost tricilíndricos están dando problemas de correas bañadas que recuerdan al caso PureTechMotor.es · Motoring press · consulted 26 September 2026 · in Spanish
Gripa el motor por problema en el manguito se queda sin refrigeranteOpinautos · Owners' forum · consulted 26 September 2026 · in Spanish
Fiabilité et pannes Volkswagen Golf IVFiches-auto.fr · Other source · consulted 27 September 2026 · in French
Fiabilité et pannes Volkswagen PassatFiches-auto.fr · Other source · consulted 27 September 2026 · in French
Fiabilité et pannes Audi A3Fiches-auto.fr · Other source · consulted 27 September 2026 · in French
Fiabilité et pannes Audi TTFiches-auto.fr · Other source · consulted 27 September 2026 · in French
Fiabilité et pannes Seat LeónFiches-auto.fr · Other source · consulted 27 September 2026 · in French
Seat Leon Mk1: Probleme, Schwachstellen, ErfahrungenGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
Prueba: Ford Fiesta 1.0 EcoBoost 100 CV (2013)km77 · Motoring press · consulted 26 September 2026 · in Spanish
Ford Mondeo Berlina Trend 1.0 EcoBoost 92 kW (125 CV) (2015-2018): precio y ficha técnicakm77 · Technical documentation · consulted 26 September 2026 · in Spanish
Ford B-MAX Trend 1.0 EcoBoost 100 CV (2012-2018): precio y ficha técnicakm77 · Technical documentation · consulted 26 September 2026 · in Spanish
List of Volkswagen Group petrol enginesWikipedia · Other source · consulted 27 September 2026
Audi TTWikipedia · Other source · consulted 27 September 2026
SEAT LeónWikipedia · Other source · consulted 27 September 2026
SEAT ToledoWikipedia · Other source · consulted 27 September 2026
Ford EcoBoost engines: reliability, problems and should you buy one?Carbuyer · Motoring press · consulted 26 September 2026
Ford's Self-Clogging 1.0-Liter EcoBoost Engine Is Finally Getting RecalledThe Drive · Motoring press · consulted 26 September 2026
The Largest Ford EcoBoost Recalls In 15 Years Of ProductionCarBuzz · Motoring press · consulted 26 September 2026
Stellantis no es el único afectado por la correa de distribución bañada en aceiteAutofácil · Motoring press · consulted 26 September 2026 · in Spanish