BMW
i8
BMW
M4
BMW i8 vs BMW M4: 2024 Comparison
The short answer
The BMW i8 offers fuel economy, while the BMW M4 excels at power instead. Choose the BMW i8 if you prioritize fuel economy in daily driving, or the BMW M4 if power matters more for your needs. Both are covered by real owner reports on CarWizz.
Specs side by side
What owners say
i8
Overall
Mixed sentiment with a clear divide between perception and ownership experience. The vehicle is widely criticized for a perceived mismatch between its dramatic, supercar-inspired styling and its actual performance capabilities, particularly when compared to contemporary BMW M cars like the F80 M3. This has led to a reputation in some circles as a "poser car" or a "lawnmower in a supercar body." However, a strong counter-narrative from long-term owners praises the i8 as a reliable, surprisingly fun-to-drive grand tourer with low maintenance costs and exceptional fuel efficiency for its appearance.
Best version to buy
Insufficient owner data available to declare a consensus "best" version. Owner discussions mention both the Coupe and Roadster (2018+) variants, with the Coupe noted for retaining small rear seats and slightly lower weight, while the Roadster sacrifices that practicality for an open-air experience.
Known issues
- ⚠Perceived performance deficit: very frequent criticism that the hybrid powertrain's output does not match the supercar styling, with specific comparisons noting it was slower in some metrics than the F80 M3 launched the same year.
- ⚠High-voltage (HV) battery reliability: isolated reports of HV battery failures requiring repair, noted as being a manageable DIY fix involving replacing individual faulty cells rather than the entire pack. Frequency: isolated.
- ⚠Fake engine sound: use of an artificial sound generator (speaker) noted as a negative by some enthusiasts. Frequency: isolated.
M4
Overall
Extremely positive sentiment among owners, characterized by high satisfaction with performance, daily drivability, and emotional fulfillment. The M4 is consistently described as a "dream car" that delivers a thrilling, occasion-like driving experience. Owners of the current G82 generation (2021+) praise its all-around capability as a perfect daily driver that is "quick enough to do everything, but also super comfortable," with a smooth ride and impressive technology.
Best version to buy
Insufficient owner data available to declare a consensus "best" version. Strong appreciation is expressed for both the F82 (2015-2020) and G82 (2021+) generations.
Known issues
- ⚠High Cost of Ownership: Very frequent warnings about expensive routine maintenance (tires, brakes) and major repairs (turbos) on used, high-mileage examples. Budgeting thousands annually is emphasized. Frequency: very frequent.
- ⚠Carbon Bucket Seat Drawbacks: Recurrent mentions of being a "pain to live with," including difficulty entering/exiting, wear on bolsters, and compromised comfort for some passengers on long trips. Frequency: recurrent.
- ⚠Risk of Purchasing Modified Used Vehicles: Recurrent strong advice against buying modified M4s due to unknown build quality, potential hidden damage from aggressive tuning, and the likelihood that the car was driven hard.
The verdict
The BMW i8 is the better choice for most buyers.
It has stronger reliability sentiment in owner reports than the BMW M4, based on the data above. If the specific known issues on the BMW i8 are a dealbreaker, the BMW M4 is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the BMW i8 or the BMW M4?
Owner reports lean more positive on reliability for the BMW i8 than the BMW M4. See the known issues comparison above for the specific concerns owners report on each.
Which is better for families, the BMW i8 or the BMW M4?
The BMW M4 seats more passengers than the BMW i8 on its catalogued best-equipped version. Body type also differs: the BMW i8 is classed as a Roadster, the BMW M4 as a Coupe.
Which has better fuel economy, the BMW i8 or the BMW M4?
The BMW i8 is more fuel-efficient on paper: 2 L/100km combined versus 10.2 L/100km for the BMW M4, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the BMW i8 or the BMW M4?
Exact maintenance costs aren't in our data, but owner reports mention cost-related concerns more often for the BMW M4 than the BMW i8. See the known issues comparison above.