A8 vs 5 Series
If you’re shopping for a car in the midsize luxury car class, the A8 and the 5 Series are likely both on your shortlist. Your answer depends on what you value. The A8 does better on engine & performance, and the 5 Series does better on fuel economy & range.
At a glance
- Engine & Performance A8 wins
- Fuel Economy & Range 5 Series wins
- Space & Practicality Tie
- Off-road & Towing Tie
- Engine & Performance3.1
- Fuel Economy & Range1.3
- Engine & Performance0.6
- Fuel Economy & Range6.2
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 5 Series has better fuel economy
The 5 Series’s 31 mpg leaves the A8’s 22 mpg well behind, so if this spec matters to you, the choice is easy. The 5 Series uses less fuel on the standard combined cycle, which matters most if you drive a lot.
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The A8 has 80 hp more power
Not a close call. The A8 lists 335 hp and the 5 Series lists 255 hp. That’s a substantial gap. More power helps with merging, overtaking and climbing hills, especially with passengers and luggage on board.
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The A8 has 74 lb-ft more torque
Among all the differences on this page, 369 lb-ft against 295 lb-ft is one of the most meaningful, and it favors the A8. The A8’s extra torque makes it more relaxed when fully loaded or towing.
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The 5 Series has better city fuel economy
The A8 gives up a lot on fuel economy (city): 20 mpg, compared with 28 mpg on the 5 Series. In town, driving style has a big effect, but the 5 Series starts from a better baseline.
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The 5 Series has better highway fuel economy
Few buyers will miss this one. The 5 Series brings 35 mpg to the table; the A8 brings 26 mpg. Highway fuel economy matters if you cover long distances at steady speeds.
Design & Size
Engine & Performance
A8 leads
This is one of the A8’s strongest areas. On engine & performance, the 5 Series falls well short. On its side, the A8 has 80 hp more power. The A8’s extra output gives it more in reserve when you need to get up to speed. For engine & performance, the A8 is the one to beat.
Total system output
A8: 335 hp 5 Series: 255 hp Power is only part of the story; weight, gearing and torque delivery shape how quick a car feels.
Torque
A8: 369 lb-ft 5 Series: 295 lb-ft Electrified powertrains deliver torque instantly, so compare torque figures alongside the powertrain type.
Fuel Economy & Range
5 Series leads
If fuel economy & range is high on your list, the 5 Series makes the stronger case by a wide margin. On the 5 Series, you get better fuel economy. Official figures rarely match real-world driving exactly, but the ranking between two cars tends to hold. If fuel economy & range is your priority, the 5 Series is the car to pick.
Fuel economy (combined)
A8: 22 mpg 5 Series: 31 mpg Better combined fuel economy lowers your running costs every week, and the savings add up over years of ownership.
Fuel economy (city)
A8: 20 mpg 5 Series: 28 mpg City fuel economy matters most if your driving is mostly short trips, traffic and stop-and-go commutes.
Space & Practicality
Too close to call
Neither the A8 nor the 5 Series has a real advantage in the space & practicality category. On space & practicality alone, you can’t go far wrong with either.
Off-road & Towing
Too close to call
The off-road & towing specs are close enough that neither gets the point. So off-road & towing is a non-factor here; move on to the areas where they actually differ.
Safety & Tech
On safety & tech, the useful details are the names in the table: what each one uses, not a figure we can rank.
Full Specifications
Engine & Performance
| Spec | A8 | 5 Series |
|---|---|---|
| Powertrain | Gas (48V mild hybrid) | Gas (48V mild hybrid) |
| Engine | 3.0L turbo V6 | 2.0L turbo I4 |
| Total system output | 335 hp (winner) | 255 hp |
| Torque | 369 lb-ft (winner) | 295 lb-ft |
| Transmission | 8-speed automatic | 8-speed automatic |
| Drivetrain | AWD (quattro) | RWD (xDrive AWD available) |
Fuel Economy & Range
| Spec | A8 | 5 Series |
|---|---|---|
| Fuel economy (combined)EPA estimate where available | 22 mpg | 31 mpg (winner) |
| Fuel economy (city) | 20 mpg | 28 mpg (winner) |
| Fuel economy (highway) | 26 mpg | 35 mpg (winner) |
Space & Practicality
| Spec | A8 | 5 Series |
|---|---|---|
| Seats | 5 seats | 5 seats |
Off-road & Towing
| Spec | A8 | 5 Series |
|---|---|---|
| AWD / 4WD available | Yes | Yes |
Safety & Tech
| Spec | A8 | 5 Series |
|---|---|---|
| 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 merge, overtake or climb hills with a full load (335 hp vs 255 hp)
- you often drive loaded up or with a trailer (369 lb-ft vs 295 lb-ft of torque)
- you’re loyal to Audi and happy with it
Choose the 5 Series if…
- you want better combined fuel economy (31 mpg vs 22 mpg)
- you want better city fuel economy (28 mpg vs 20 mpg)
- you cover long highway distances (35 mpg vs 26 mpg on the highway)
Also Compared
Frequently Asked Questions
Should I buy the A8 or the 5 Series?
Neither wins outright. Choose the A8 if engine & performance matters most, or the 5 Series if fuel economy & range does.
Executive Summary
Here’s my take on Audi’s A8 versus BMW’s 5 Series. I’d put 80 hp more power at the top of the list, and it belongs to the A8. Fairness check: the 5 Series does come with better fuel economy.
Match the strength to your habits (engine & performance for the A8, fuel economy & range for the 5 Series), and you won’t go far wrong.
My pick: both are fair choices, with the A8 leaning toward engine & performance and the 5 Series toward fuel economy & range.
Personal opinion based on the data above. Your priorities may differ.