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Honda e:HEV / i-MMD vs Porsche MA1 / 9A1: which engine is more reliable?

According to our risk index, the Porsche MA1 / 9A1 carries less risk than the Honda e:HEV / i-MMD: 25/100 versus 34/100 (both moderate risk). The Honda e:HEV / i-MMD has 2 documented serious faults, the main one being «Cracked high-pressure fuel pump (Honda campaign 6YP)»; the Porsche MA1 / 9A1 has 1 documented serious fault, the main one being «Bore scoring in the MA1 of the 997.2 and 987.2: uncommon, but documented».

Risk index

Honda e:HEV / i-MMD

34

Moderate risk · 2 serious faults

Risk index

Porsche MA1 / 9A1

25

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

16 sourcesHow we work

Is the Honda e:HEV / i-MMD reliable?

The Honda e:HEV hybrid system (formerly i-MMD) has no serious, widespread faults documented in the sources consulted. The most cited issue is the 12 V battery going flat when the car stands unused and, on the 2.0, a recall for the high-pressure fuel pump.[1][2][3]

See the 3 of the Honda e:HEV / i-MMD faults

Is the Porsche MA1 / 9A1 reliable?

Yes, it is noticeably more reliable than the M96/M97: it eliminated the intermediate shaft with its IMS bearing and, according to FCP Euro, the connecting rod bolt failures. What is documented is minor: carbon build-up on the intake valves caused by direct injection, coolant pump leaks on the 991.1 and, rarely, bore scoring on the 997.2.[4][5][6][7]

See the 3 of the Porsche MA1 / 9A1 faults

Side-by-side comparison

Comparison of Honda e:HEV / i-MMD and Porsche MA1 / 9A1
Honda e:HEV / i-MMDPorsche MA1 / 9A1
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement——
TimingChainChain
Power109–184 hp255–400 hp
Productionsince 2018[1][8]2009–2016[4][7][9][10][11][12][13]
Reliability
Risk index (what is it?)34Moderate risk25Moderate risk
Documented faults33
Of high or critical severity21
Worst severityHigh severityCritical severity
Main faults
  1. High severity: Cracked high-pressure fuel pump (Honda campaign 6YP)
  2. High severity: Faulty fuel pump impeller on the 2019-2020 CR-V hybrid (Honda 6FE campaign)
  3. Low severity: 12 V battery going flat and hybrid system failing to start
  1. Critical severity: Bore scoring in the MA1 of the 997.2 and 987.2: uncommon, but documented
  2. Medium severity: Carbon build-up on the intake valves caused by direct injection
  3. Medium severity: Leaks from the electronically controlled coolant pumps of the 991.1 and the plastic water pump
Most expensive documented repairup to €25012 V battery going flat and hybrid system failing to startPublished figure[1]No reliable data
Which versions to buy
BuyRecommended versions
  • e:HEV 1.5 (LEB-H5) 109-131 hp system output (Jazz IV, HR-V III)[1][8]
  • 3.6 Carrera 345 hp (MA1.02, 2009-2012)[4][6][7]
  • 3.8 Carrera S 385 hp (MA1.01, 2009-2012)[6][7]
  • 2.9 Boxster/Cayman 255-265 hp (MA1.20, 2009-2012, no direct injection)[5][9]
With cautionVersions to be cautious about
  • i-MMD 2.0 184 hp system output (CR-V V hybrid)[1][2]
  • e:HEV 2.0 184 hp system output (Civic XI)[2][14]
  • 3.4 Boxster S / Cayman S 310-320 hp (MA1.21/.22, 2009-2012, direct injection)[5][15]
  • 3.4 Carrera 350 hp (MA1.04, 2011-2015)[6]
  • 3.8 Carrera S 400 hp (MA1.03, 2011-2015)[6]
  • 2.7 Boxster/Cayman 265-275 hp (MA1.22, 2012-2016)[15][16]
  • 3.4 Boxster S / Cayman S / GTS 315-340 hp (MA1.23, 2012-2016)[15][16]
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

Honda e:HEV / i-MMD

Porsche MA1 / 9A1

Other comparisons

With the Honda e:HEV / i-MMD

With the Porsche MA1 / 9A1

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. Sistema híbrido Honda e:HEV (i-MMD): problemas, fiabilidad y coches que lo llevanMotordex · Technical documentation · consulted 29 October 2026 · in Spanish
  2. Honda recalls 1.3 million cars: fuel pump fire risk (KBA 14559R)Car-Recalls.eu · Motoring press · published 17 March 2025 · consulted 29 October 2026
  3. Fiabilité Honda HR-V (2022): pannes et témoignagesFiches-auto.fr · Motoring press · consulted 30 October 2026 · in French
  4. The Definitive Guide To Porsche 997 Engines (M96.05, M97, MA1)FCP Euro · Other source · published 16 January 2024 · consulted 2 November 2026
  5. Porsche 987: The Cayman and Boxster Generation GuideRenn Driver · Other source · published 1 November 2026 · consulted 2 November 2026
  6. Porsche 911: 5 Generationen im Gebrauchtwagen-CheckAUTO BILD · Motoring press · published 22 September 2026 · consulted 2 November 2026 · in German
  7. Porsche 997Wikipedia · Other source · consulted 2 November 2026
  8. Honda LEB-H5 (1.5 i-MMD e:HEV): experiencias, problemas, consumo y consejos de compraAutohints · Technical documentation · consulted 29 October 2026 · in Spanish
  9. Porsche Boxster and Cayman (987)Wikipedia · Other source · consulted 2 November 2026
  10. Porsche 991Wikipedia · Other source · consulted 2 November 2026
  11. Porsche Boxster and Cayman (981)Wikipedia · Other source · consulted 2 November 2026
  12. Differences between M96 and M97 enginesFlat Six Innovations · Other source · published 25 November 2025 · consulted 2 November 2026
  13. List of Porsche enginesWikipedia · Other source · consulted 2 November 2026
  14. Guide d'achat Honda Civic (nueva campaña 6YP, 4.740 híbridos en Francia)L'argus · Motoring press · published 7 January 2025 · consulted 29 October 2026 · in French
  15. Porsche Cayman and Boxster Common Problems: A Specialist Field GuideForeign Automotive · Other source · consulted 2 November 2026
  16. Porsche 981: The Cayman and Boxster Generation GuideRenn Driver · Other source · consulted 2 November 2026