A8 vs S90
Put the A8 next to the S90 and you have Audi and Volvo going after exactly the same midsize luxury car crowd. Here the question is less “which is better?” and more “which strength do you need?” Is it engine & performance with the A8, or fuel economy & range with the S90?
At a glance
- Engine & Performance A8 wins
- Fuel Economy & Range S90 wins
- Space & Practicality Tie
- Off-road & Towing Tie
- Engine & Performance3.1
- Fuel Economy & Range1.3
- Engine & Performance1.4
- Fuel Economy & Range3.9
Spec scores (0 to 10) are calculated from manufacturer specs against other models in the same class. See how the formula works. They are not reviews or user ratings.
Key Differences
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The S90 has better fuel economy
Not a close call. The S90 lists 26 mpg and the A8 lists 22 mpg. That’s a substantial gap. The S90 uses less fuel on the standard combined cycle, which matters most if you drive a lot.
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The A8 has 59 lb-ft more torque
Among all the differences on this page, 369 lb-ft against 310 lb-ft is one of the most meaningful, and it favors the A8. Electrified powertrains deliver torque instantly, so compare torque figures alongside the powertrain type.
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The A8 has 40 hp more power
The A8 gets a small bonus on total system output, with 335 hp against the S90’s 295 hp. Power is only part of the story; weight, gearing and torque delivery shape how quick a car feels.
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The S90 has better highway fuel economy
The A8 gives up a lot on fuel economy (highway): 26 mpg, compared with 31 mpg on the S90. Speed, wind and load affect highway use a lot, but the official rating is a fair comparison point.
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The S90 has better city fuel economy
Few buyers will miss this one. The S90 brings 23 mpg to the table; the A8 brings 20 mpg. City fuel economy matters most if your driving is mostly short trips, traffic and stop-and-go commutes.
Design & Size
Engine & Performance
A8 leads
The engine & performance comparison is one-sided. The A8 leads where it counts. Point to the A8 for 59 lb-ft more torque. More torque means stronger pulling from low speeds, which you feel when accelerating from a stop or climbing grades. The takeaway: on engine & performance, the A8 is the stronger car.
Torque
A8: 369 lb-ft S90: 310 lb-ft The A8’s extra torque makes it more relaxed when fully loaded or towing.
Total system output
A8: 335 hp S90: 295 hp The A8’s extra output gives it more in reserve when you need to get up to speed.
Fuel Economy & Range
S90 leads
The S90 is the clear pick if fuel economy & range is what you care about most. The S90 has the edge with better fuel economy. Better combined fuel economy lowers your running costs every week, and the savings add up over years of ownership. Weighing only fuel economy & range, the S90 comes out ahead.
Fuel economy (combined)
A8: 22 mpg S90: 26 mpg Official figures rarely match real-world driving exactly, but the ranking between two cars tends to hold.
Fuel economy (highway)
A8: 26 mpg S90: 31 mpg The S90 uses less fuel on the highway, a real saving on road trips and long commutes.
Space & Practicality
Too close to call
The differences on space & practicality are small enough to ignore in daily use. Either car will serve you equally well on space & practicality.
Off-road & Towing
Too close to call
Neither the A8 nor the S90 has a real advantage in the off-road & towing category. On off-road & towing alone, you can’t go far wrong with either.
Safety & Tech
We don’t score this area directly, because the safety & tech specs are labels rather than measurements. The table shows what each lists.
Full Specifications
Engine & Performance
| Spec | A8 | S90 |
|---|---|---|
| Powertrain | Gas (48V mild hybrid) | Gas (48V mild hybrid) |
| Engine | 3.0L turbo V6 | 2.0L turbo- and supercharged I4 |
| Total system output | 335 hp (winner) | 295 hp |
| Torque | 369 lb-ft (winner) | 310 lb-ft |
| Transmission | 8-speed automatic | 8-speed automatic |
| Drivetrain | AWD (quattro) | AWD |
Fuel Economy & Range
| Spec | A8 | S90 |
|---|---|---|
| Fuel economy (combined)EPA estimate where available | 22 mpg | 26 mpg (winner) |
| Fuel economy (city) | 20 mpg | 23 mpg (winner) |
| Fuel economy (highway) | 26 mpg | 31 mpg (winner) |
Space & Practicality
| Spec | A8 | S90 |
|---|---|---|
| Seats | 5 seats | 5 seats |
Off-road & Towing
| Spec | A8 | S90 |
|---|---|---|
| AWD / 4WD available | Yes | Yes |
Safety & Tech
| Spec | A8 | S90 |
|---|---|---|
| Basic warranty | 4 yr / 50,000 mi | 4 yr / 50,000 mi |
“N/A” means the manufacturer does not specify the value or we could not confirm it. Figures marked “manufacturer rating” are the maker’s own claims, not our measurements.
Which One Should You Buy?
Choose the A8 if…
- you want more pulling power from low speeds (369 lb-ft vs 310 lb-ft of torque)
- you merge, overtake or climb hills with a full load (335 hp vs 295 hp)
- you prefer staying with Audi
Choose the S90 if…
- you want better combined fuel economy (26 mpg vs 22 mpg)
- you want better highway fuel economy (31 mpg vs 26 mpg)
- you mostly drive in town (23 mpg vs 20 mpg in the city)
Also Compared
Frequently Asked Questions
Should I buy the A8 or the S90?
The A8 and the S90 split the comparison (engine & performance for the A8, fuel economy & range for the S90), so pick the strength you’ll use.
Executive Summary
Whenever Audi and Volvo go head to head, I learn something about what each one cares about, and the A8 and the S90 are no exception. I’d put 59 lb-ft more torque at the top of the list, and it belongs to the A8. The S90 has a trump card of its own in better fuel economy.
Fit matters more than scores here. The A8 suits buyers focused on engine & performance; the S90 suits those focused on fuel economy & range.
My pick: there’s no single winner, so choose the A8 for engine & performance or the S90 for fuel economy & range.
Personal opinion based on the data above. Your priorities may differ.