BMW 3 Series — MPG & Fuel Costs 2025
BMW's benchmark executive saloon and estate. The 320d diesel is particularly economical, while the plug-in hybrid (330e) suits company car drivers.
The BMW 3 Series is the definitive compact executive car, celebrated for its rear-wheel-drive dynamics, premium build quality, and cutting-edge driver tech. It is a favorite among business professionals and driving enthusiasts.
Engine choices include refined four-cylinder petrols, highly efficient mild-hybrid diesels, and the popular 330e plug-in hybrid. The 320d diesel has long been the champion of high-mileage drivers, combining punchy performance with low fuel usage.
A real-world return of 51 MPG on the 320d is outstanding for a car of this size and capability. The 3 Series is aerodynamically efficient, meaning motorway fuel consumption remains very low even at higher cruising speeds.
TL;DR
38 MPG
Real-world petrol
51 MPG
Real-world diesel
59L
Tank capacity
£80.71
Full tank (petrol)
16.4p
Per mile (petrol)
Real-World Fuel Economy: The BMW 3 Series achieves an estimated 38 MPG (petrol) and 51 MPG (diesel) in real-world UK driving conditions, accounting for a 12% WLTP real-world penalty.
Forecourt Fuel Cost: Refueling the 59-litre tank completely costs approximately £80.71 (petrol) or £83.84 (diesel) at average UK fuel price rates.
Fuel economy at a glance
38
Real-world MPG
Petrol
44.8
Official WLTP
Petrol
51
Real-world MPG
Diesel
60.1
Official WLTP
Diesel
Annual fuel costs by mileage
| Annual mileage | Petrol | Diesel |
|---|---|---|
| 5,000 miles/yr | £818 | £633 |
| 7,400 miles/yr(UK average) | £1211 | £937 |
| 10,000 miles/yr | £1637 | £1267 |
| 15,000 miles/yr | £2455 | £1900 |
| 20,000 miles/yr | £3273 | £2533 |
| Full tank (59L) | £80.71 | £83.84 |
| Cost per mile | 16.4p | 12.7p |
Based on UK average fuel prices: petrol 136.8p/L · diesel 142.1p/L. Prices updated regularly.
How does the 3 Series compare?
Tips to get better MPG from your 3 Series
On PHEV (330e) models, use the navigation system so the car can manage battery usage optimally across your route.
Engage Eco Pro mode on the motorway to allow the automatic transmission to coast freely when you lift off.
Keep tyre pressures checked; the wider sporty tyres on M Sport models have higher rolling resistance if under-inflated.
Is the cheaper petrol station worth it?
In a BMW 3 Series achieving ~38 MPG real-world, if you fill 47 litres and the alternative station is 10p/litre cheaper:
£4.70
Gross saving on fuel
£0.49
Cost of 3-mile detour
£4.21
Net saving ✓
You could drive up to 29 miles round-trip before the saving disappears entirely.
Calculate for your exact situationPopular variants
Frequently asked questions
What is the real-world MPG of the BMW 3 Series?
The BMW 3 Series achieves approximately 38 MPG in real-world petrol driving — around 12% lower than the official WLTP figure of 44.8 MPG due to real driving conditions. Diesel variants achieve around 51 MPG real-world.
How much does it cost to fill a BMW 3 Series?
The BMW 3 Series has a fuel tank of 59 litres. At the UK average of 136.8p/litre for petrol, a full tank costs approximately £80.71. Diesel costs approximately £83.84 for a full tank.
What is the annual fuel cost for a BMW 3 Series?
At the UK average annual mileage of 7,400 miles and current petrol price of 136.8p/litre, a BMW 3 Series costs approximately £1211 per year in fuel. At 10,000 miles/year the cost rises to £1637. Actual costs vary with your driving style and mileage.
Is it worth driving to a cheaper petrol station in a BMW 3 Series?
In a BMW 3 Series doing ~38 MPG real-world, driving 3 miles round-trip to save 10p/litre on a 47-litre fill nets approximately £4.21 after the extra fuel cost. You could drive up to 29 miles before the saving is eaten up. Use the WorthThePump calculator for your exact situation.
How much does the BMW 3 Series cost per mile in fuel?
The BMW 3 Series costs approximately 16.4p per mile in petrol at current UK prices. Over a typical commute of 30 miles per day, that is approximately £4.92 per day in fuel.
What is the WLTP MPG figure for the BMW 3 Series?
The official WLTP fuel economy figure for the BMW 3 Series is 44.8 MPG. However, real-world MPG is typically 10–15% lower than WLTP due to cold starts, air conditioning, motorway speeds, and varying loads. WorthThePump uses a 12% real-world penalty to give a more accurate estimate.
Related guides
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