DecodedCarsAudi S6 vs BMW 3 Series
2025 Audi S6 vs 2025 BMW 3 Series — two rivals compared on efficiency, size, safety and reliability.
The short version
The BMW 3 Series is more fuel-efficient: 31 vs 22 MPG combined in its best version.
That works out to about $1,100 a year less in fuel for the BMW 3 Series (EPA estimate, 15,000 miles).
The Audi S6 is the bigger car, about 10 inches longer.
Across all model years since 2005, the BMW 3 Series has had fewer recall campaigns (4 vs 19).
The two cars
The 2025 Audi S6 is a midsize car offered with a 2.9L 6-cyl engine, including a hybrid version and all-wheel drive. It measures about 195 inches long and 74 inches wide on a 115-inch wheelbase, with a curb weight of roughly 4,495 lb.
The 2025 BMW 3 Series is a compact car offered with 2 engines (2.0L 4-cyl turbo and 3.0L 4-cyl turbo), including a hybrid version and rear-wheel drive and all-wheel drive. It measures about 185 inches long and 72 inches wide on a 112-inch wheelbase, with a curb weight of roughly 3,902 lb (3-Series 330e 4dr Sedan).
Buying used? The 2024 S6 and the 2024 3 Series have the fewest problems in our data; avoid the 2021 S6.
Basics
Efficiency
Performance & space
Safety & reliability
Interest
Green = clearly better. Prices are not included. How we calculate this →
Which one should you choose?
Choose the Audi S6 if…
- You want more room (10 in longer)
Choose the BMW 3 Series if…
- You want lower fuel bills (31 vs 22 MPG)
- You want something easier to park (10 in shorter)
- You put reliability history first (4 vs 19 recalls since 2005)
Pros & cons of each
2025 Audi S6
- Strong performanceUp to 670 hp, versus about 320 hp for similar 2025 models.
- Hybrid version availableOffered as a hybrid as well as gas.
- Lots of standard safety tech4 of 5 key driver aids standard on the versions we checked.
- Below-average fuel economyBest version gets 22 MPG combined, 27% below the 2025 midsize car average of 30 MPG.
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
2025 BMW 3 Series
- Hybrid version availableOffered as a hybrid as well as gas.
- AWD / 4WD available
- No recalls so far
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
Full 2025 Audi S6 specs →Full 2025 BMW 3 Series specs →Compare fuel costs for your driving →Compare size & garage fit →