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0.9 TwinAir and 1.0/1.3 FireFly vs 1.5 VTi-TECH / T-GDI: which engine is more reliable?

According to our risk index, the 1.5 VTi-TECH / T-GDI carries less risk than the 0.9 TwinAir and 1.0/1.3 FireFly: 7/100 (low risk) versus 32/100 (moderate risk). The 0.9 TwinAir and 1.0/1.3 FireFly has 1 documented serious fault, the main one being «Early turbocharger failure (0.9 TwinAir)»; the 1.5 VTi-TECH / T-GDI has no documented serious faults.

Risk index

0.9 TwinAir and 1.0/1.3 FireFly

32

Moderate risk · 1 serious fault

Risk index

1.5 VTi-TECH / T-GDI

7

Low risk · 0 serious faults

Lower risk

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

21 sourcesHow we work

Is the 0.9 TwinAir and 1.0/1.3 FireFly reliable?

The 0.9 TwinAir (2010-2020) and the 1.0/1.3 FireFly (from 2018, with a mild-hybrid version from 2020) are the small petrol engines of Fiat, Jeep and Lancia. The TwinAir has no systemic faults, but it does have repeated, minority cases of turbo, MultiAir unit, oil consumption and clutch or flywheel wear, consistent with its uneven two-cylinder running. The newer FireFly has so far recorded little more than isolated Start&Stop faults.[1][2][3][4][5]

See the 5 of the 0.9 TwinAir and 1.0/1.3 FireFly faults

Is the 1.5 VTi-TECH / T-GDI reliable?

MG/SAIC's "1.5" covers two different engines: the naturally aspirated VTi-TECH (106 hp), the entry-level engine in the MG ZS, and the turbocharged T-GDI (162-170 hp), found only in the MG HS and as the petrol engine in its plug-in hybrids. Neither has well-documented engine faults in independent sources yet: the complaints published concern electronics, the automatic gearbox and finish, not the engine block.[6][7][8][9][10][11]

See the 2 of the 1.5 VTi-TECH / T-GDI faults

Side-by-side comparison

Comparison of 0.9 TwinAir and 1.0/1.3 FireFly and 1.5 VTi-TECH / T-GDI
0.9 TwinAir and 1.0/1.3 FireFly1.5 VTi-TECH / T-GDI
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement——
TimingChainChain
Power70–180 hp106–170 hp
Productionsince 2010[12][13]since 2017[6][7][14][15][16]
Reliability
Risk index (what is it?)32Moderate risk7Low risk
Documented faults52
Of high or critical severity10
Worst severityHigh severityLow severity
Main faults
  1. High severity: Early turbocharger failure (0.9 TwinAir)
  2. Medium severity: MultiAir/UniAir hydraulic unit failure (0.9 TwinAir)
  3. Medium severity: Clutch and flywheel wear (0.9 TwinAir)
  1. Low severity: Jerky or harsh automatic gearbox shifts when cold or at low speed (MG HS)
  2. Low severity: Electronic warnings and occasional sensor faults (MG HS)
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versions
  • 1.0 FireFly Hybrid 70 hp (GSE, from 2020)[1][2]
  • 1.0 GSE T3 Turbo 100-120 hp (FireFly, from 2018)[3][17]
  • 1.5 VTi-TECH naturally aspirated 106 hp (NSE / NSE Plus, from 2017)[9]
With cautionVersions to be cautious about
  • 0.9 TwinAir 78-105 hp (2010-2020)[1][2][4][5]
  • 1.3 GSE T4 Turbo 150-180 hp (FireFly, from 2018)[3]
  • 1.0 FireFly N3 flex 6V 71-77 hp (South America, from 2016)[18][19]
  • 1.3 FireFly N4 flex 8V 98-109 hp (South America, from 2017)[18][19]
  • 1.5 T-GDI turbo 162 hp (GS61H, 2018-2024)[10][11][20][21]
  • 1.5 T-GDI turbo 170 hp (15FDE / 15FKE, from 2024)[7]
AvoidVersions to avoidNoneNone

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

Cars that each one is fitted to

0.9 TwinAir and 1.0/1.3 FireFly

See the 9 models with the 0.9 TwinAir and 1.0/1.3 FireFly

1.5 VTi-TECH / T-GDI

Other comparisons

With the 0.9 TwinAir and 1.0/1.3 FireFly

With the 1.5 VTi-TECH / T-GDI

Compare other engines

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Sources

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

  1. Fiabilité et pannes de la Fiat 500 (2007)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  2. Fiabilité et pannes de la Fiat Panda (depuis 2012)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  3. Fiabilité et pannes du Jeep RenegadeFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  4. Fiat 500 (ab 2007) – alle bekannten Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · published 24 November 2023 · consulted 27 September 2026 · in German
  5. Fiat Panda III (seit 2011) – Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 21 January 2023 · consulted 27 September 2026 · in German
  6. MG ZS (crossover)Wikipedia (inglés) · Other source · consulted 27 September 2026
  7. MG HSWikipedia (inglés) · Other source · consulted 27 September 2026
  8. Essai complet : MG ZSFiches-Auto.fr · Motoring press · consulted 27 September 2026 · in French
  9. Fiabilité et pannes du MG ZSFiches-Auto.fr · Motoring press · consulted 27 September 2026 · in French
  10. Fiabilité et pannes du MG eHSFiches-Auto.fr · Motoring press · consulted 27 September 2026 · in French
  11. MG HS PHEV: guía definitiva de problemas y soluciones del SUV, el híbrido enchufable más vendidoAutopista.es · Motoring press · published 10 November 2025 · consulted 27 September 2026 · in Spanish
  12. Fiat TwinAir engineWikipedia (inglés) · Other source · consulted 27 September 2026
  13. Fiat Global Small EngineWikipedia (inglés) · Other source · consulted 27 September 2026
  14. MG HSWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  15. MG HSWikipedia (francés) · Other source · consulted 27 September 2026 · in French
  16. List of General Motors enginesWikipedia (inglés) · Other source · consulted 27 September 2026
  17. Fiabilité et pannes de la Fiat 500XFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  18. Fiat tem recall para Pulse, Argo, Cronos, Fiorino, Mobi e StradaMotor Show · Motoring press · published 14 December 2022 · consulted 2 November 2026 · in Portuguese
  19. Fiat faz recall de Strada, Pulse e mais 4 modelos por risco de vazamento de combustívelGaragem 360 · Motoring press · published 9 December 2022 · consulted 2 November 2026 · in Portuguese
  20. MG – Common problems (llamadas a revisión de la UE y del Reino Unido)car-recalls.eu · Other source · consulted 30 October 2026
  21. MG HS SUV (2019-2024) Exclusive 1.5T-GDI 5d: opinión de propietario (10 jun 2022)Parkers · Owners' forum · published 10 June 2022 · consulted 30 October 2026