BMW 6 Series — MPG & Fuel Costs 2025
A large, luxury Grand Tourer available as a Coupe, Convertible, or four-door Gran Coupe. Refined cruiser.
The BMW 6 Series (F12/F13/F06 generation) is a large luxury grand tourer, with the four-door Gran Coupe version being a massive sales success in the UK executive car market.
The standout engine is the 640d, a twin-turbocharged 3.0-litre straight-six diesel that offers near-supercar torque combined with remarkable fuel economy for a car of its size.
Real-world motorway runs see the 640d returning an impressive 42-45 MPG, while the 640i petrol models yield around 30 MPG under similar conditions.
TL;DR
29 MPG
Real-world petrol
41 MPG
Real-world diesel
70L
Tank capacity
£95.76
Full tank (petrol)
21.4p
Per mile (petrol)
Real-World Fuel Economy: The BMW 6 Series achieves an estimated 29 MPG (petrol) and 41 MPG (diesel) in real-world UK driving conditions, accounting for a 12% WLTP real-world penalty.
Forecourt Fuel Cost: Refueling the 70-litre tank completely costs approximately £95.76 (petrol) or £99.47 (diesel) at average UK fuel price rates.
Fuel economy at a glance
29
Real-world MPG
Petrol
34.5
Official WLTP
Petrol
41
Real-world MPG
Diesel
50.4
Official WLTP
Diesel
Annual fuel costs by mileage
| Annual mileage | Petrol | Diesel |
|---|---|---|
| 5,000 miles/yr | £1072 | £788 |
| 7,400 miles/yr(UK average) | £1587 | £1166 |
| 10,000 miles/yr | £2144 | £1576 |
| 15,000 miles/yr | £3217 | £2363 |
| 20,000 miles/yr | £4289 | £3151 |
| Full tank (70L) | £95.76 | £99.47 |
| Cost per mile | 21.4p | 15.8p |
Based on UK average fuel prices: petrol 136.8p/L · diesel 142.1p/L. Prices updated regularly.
How does the 6 Series compare?
Tips to get better MPG from your 6 Series
The 640d straight-six diesel is exceptionally efficient; cruise at a steady 65-70 mph on motorways.
Keep the large wheels properly aligned to prevent scrubbing drag and uneven wear.
Use the gearshift paddles in manual mode on hilly terrain to avoid unnecessary downshifts.
Is the cheaper petrol station worth it?
In a BMW 6 Series achieving ~29 MPG real-world, if you fill 56 litres and the alternative station is 10p/litre cheaper:
£5.60
Gross saving on fuel
£0.64
Cost of 3-mile detour
£4.96
Net saving ✓
You could drive up to 26 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 6 Series?
The BMW 6 Series achieves approximately 29 MPG in real-world petrol driving — around 12% lower than the official WLTP figure of 34.5 MPG due to real driving conditions. Diesel variants achieve around 41 MPG real-world.
How much does it cost to fill a BMW 6 Series?
The BMW 6 Series has a fuel tank of 70 litres. At the UK average of 136.8p/litre for petrol, a full tank costs approximately £95.76. Diesel costs approximately £99.47 for a full tank.
What is the annual fuel cost for a BMW 6 Series?
At the UK average annual mileage of 7,400 miles and current petrol price of 136.8p/litre, a BMW 6 Series costs approximately £1587 per year in fuel. At 10,000 miles/year the cost rises to £2144. Actual costs vary with your driving style and mileage.
Is it worth driving to a cheaper petrol station in a BMW 6 Series?
In a BMW 6 Series doing ~29 MPG real-world, driving 3 miles round-trip to save 10p/litre on a 56-litre fill nets approximately £4.96 after the extra fuel cost. You could drive up to 26 miles before the saving is eaten up. Use the WorthThePump calculator for your exact situation.
How much does the BMW 6 Series cost per mile in fuel?
The BMW 6 Series costs approximately 21.4p per mile in petrol at current UK prices. Over a typical commute of 30 miles per day, that is approximately £6.42 per day in fuel.
What is the WLTP MPG figure for the BMW 6 Series?
The official WLTP fuel economy figure for the BMW 6 Series is 34.5 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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