Q3 vs GLB
The Q3 and the GLB are direct rivals in the subcompact luxury suv class, one from Audi and one from Mercedes-Benz. You won’t find a dramatic mismatch here: the Q3 and the GLB are close on nearly every line that counts.
At a glance
- Engine & Performance Tie
- Fuel Economy & Range GLB wins
- Space & Practicality Tie
- Off-road & Towing Tie
- Engine & Performance5.2
- Fuel Economy & Range3.7
- Engine & Performance4.9
- Fuel Economy & Range5.4
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 GLB has better fuel economy
Don’t expect a night-and-day difference here. 28 mpg against 25 mpg is a small but genuine lead for the GLB. Better combined fuel economy lowers your running costs every week, and the savings add up over years of ownership.
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The GLB has better highway fuel economy
The GLB nudges ahead with 33 mpg, while the Q3 lists 29 mpg. Speed, wind and load affect highway use a lot, but the official rating is a fair comparison point.
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The GLB has better city fuel economy
This one is close enough that other factors could outweigh it, but on paper the GLB leads with 25 mpg to 22 mpg. City fuel economy matters most if your driving is mostly short trips, traffic and stop-and-go commutes.
Design & Size
Engine & Performance
Too close to call
Call the engine & performance round a draw. So engine & performance is a non-factor here; move on to the areas where they actually differ.
Fuel Economy & Range
GLB leads
In this area the GLB has a lead the Q3 can’t close. The GLB answers with better fuel economy. The GLB uses less fuel on the standard combined cycle, which matters most if you drive a lot. If this section decides it for you, choose the GLB.
Fuel economy (combined)
Q3: 25 mpg GLB: 28 mpg Official figures rarely match real-world driving exactly, but the ranking between two cars tends to hold.
Fuel economy (highway)
Q3: 29 mpg GLB: 33 mpg Highway fuel economy matters if you cover long distances at steady speeds.
Space & Practicality
Too close to call
The differences on space & practicality are small enough to ignore in daily use. Treat space & practicality as common ground and look elsewhere for the deciding factor.
Off-road & Towing
Too close to call
Side by side, the off-road & towing figures for the Q3 and the GLB barely differ. In short, off-road & towing is a draw; the decision lies elsewhere.
Safety & Tech
The safety & tech data here comes as names and types, not scores. Check the table to see what each one uses.
Full Specifications
Engine & Performance
| Spec | Q3 | GLB |
|---|---|---|
| Powertrain | Gas | Gas (48V mild hybrid) |
| Engine | 2.0L turbo I4 | 2.0L turbo I4 |
| Total system output | 228 hp | 221 hp |
| Torque | 251 lb-ft | 258 lb-ft |
| Transmission | 8-speed automatic | 8-speed dual-clutch |
| Drivetrain | AWD (quattro) | FWD (4MATIC AWD available) |
Fuel Economy & Range
| Spec | Q3 | GLB |
|---|---|---|
| Fuel economy (combined)EPA estimate where available | 25 mpg | 28 mpg (winner) |
| Fuel economy (city) | 22 mpg | 25 mpg (winner) |
| Fuel economy (highway) | 29 mpg | 33 mpg (winner) |
Space & Practicality
| Spec | Q3 | GLB |
|---|---|---|
| Seats | 5 seats | 5 seats |
Off-road & Towing
| Spec | Q3 | GLB |
|---|---|---|
| AWD / 4WD available | Yes | Yes |
Safety & Tech
| Spec | Q3 | GLB |
|---|---|---|
| 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 GLB if…
- you want better combined fuel economy (28 mpg vs 25 mpg)
- you want better highway fuel economy (33 mpg vs 29 mpg)
- you mostly drive in town (25 mpg vs 22 mpg in the city)
Also Compared
Frequently Asked Questions
Which is better for most people, the Q3 or the GLB?
On the specs compared here, the GLB makes more sense for most buyers; the Q3 doesn’t win a single measurable area.
Executive Summary
The Q3 versus the GLB is a matchup I find genuinely interesting, because Audi and Mercedes-Benz made different bets. I’d put better fuel economy at the top of the list, and it belongs to the GLB. Nor should you ignore that the GLB has better city fuel economy.
Choose by what you’d use most: the things a spec sheet can’t capture leads to the Q3, fuel economy & range leads to the GLB.
My pick: the GLB.
Personal opinion based on the data above. Your priorities may differ.