Alpina
B8
BMW
M6
Alpina B8 vs BMW M6: 2025 Comparison
The short answer
The Alpina B8 offers power, while the BMW M6 excels at fuel economy instead. Choose the Alpina B8 if you prioritize power in daily driving, or the BMW M6 if fuel economy matters more for your needs. Both are covered by real owner reports on CarWizz.
Specs side by side
What owners say
B8
Overall
Owner sentiment is highly fragmented due to discussions covering two distinct generations separated by decades. For the classic E36-era B8 (based on the 3 Series), sentiment among long-term owners is heavily focused on maintenance, with the vehicle described as a "very rare 330ci" that requires diligent, specialized upkeep. The car is praised for its "magical" Alpina-tuned suspension offering a supple yet sporty ride.
Best version to buy
Insufficient owner data available to designate a best version. For the classic E36, one owner strongly recommends retaining all Alpina-specific parts, especially the springs, for the intended driving experience.
Known issues
- ⚠(Note: All issues below pertain specifically to the classic E36-generation Alpina B8 with the M60B46 V8 engine) Head gasket failure: Potential failure point; recommended to monitor via used oil analysis for elevated moisture.
M6
Overall
Sentiment is deeply polarized and highly conditional. The vehicle is universally revered for its high-revving 5.0L V10 (S85) engine, described as an "insanely fast" and "brilliant" powerplant above 5,000 RPM, offering a unique and thrilling driving experience that creates significant owner pride and excitement. However, this is heavily counterbalanced by very frequent and severe criticism regarding legendary reliability concerns and extreme ownership costs.
Best version to buy
Insufficient owner data available to designate a specific model year or trim (e.g., Competition Package) as the "best." The primary differentiator discussed is transmission choice. The 6-speed manual (6MT) is highly prized for its rarity, driver engagement, and because it avoids the notorious reliability issues of the SMG III automated manual transmission.
Known issues
- ⚠Rod bearing failures in the S85 V10 engine: considered a critical, well-documented flaw requiring preventative replacement; catastrophic engine failure risk. Frequency: very frequent.
- ⚠SMG III transmission reliability: prone to major failures, expensive repairs, and criticized for poor drivability in daily use. Frequency: very frequent.
- ⚠Throttle actuator failures: another common and expensive fault with the S85 engine. Frequency: very frequent.
The verdict
The BMW M6 is the better choice for most buyers.
It has better fuel economy on its best-equipped version than the Alpina B8, based on the data above. If power matters more to you than running costs, the Alpina B8 is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the Alpina B8 or the BMW M6?
Owner reports show similar reliability sentiment for the Alpina B8 and the BMW M6. Check the known issues listed above for specific differences between the two.
Which is better for families, the Alpina B8 or the BMW M6?
Both seat a similar number of passengers based on our data. The Alpina B8 is classed as a Coupe, the BMW M6 as a Sedan, which affects cargo space and ride height for family use.
Which has better fuel economy, the Alpina B8 or the BMW M6?
The BMW M6 is more fuel-efficient on paper: 10.3 L/100km combined versus 11.8 L/100km for the Alpina B8, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the Alpina B8 or the BMW M6?
Exact maintenance costs aren't in our data, but owner reports mention cost-related concerns more often for the BMW M6 than the Alpina B8. See the known issues comparison above.