BMW 8 Series — MPG & Fuel Costs 2025
BMW's modern flagship GT, combining high-tech luxury with serious performance and xDrive security.
The modern BMW 8 Series resurrected the iconic nameplate to replace the 6 Series as BMW's premium luxury Grand Tourer, available as a Coupe, Convertible, and Gran Coupe.
Engine choices are highly advanced, including the rear-wheel-drive 840i petrol and the all-wheel-drive 840d diesel. The 840d uses multi-stage turbocharging for instant torque.
Real-world fuel economy is highly respectable, with the 840d diesel returning 35-38 MPG on motorway journeys and the 840i petrol averaging around 28 MPG.
TL;DR
22 MPG
Real-world petrol
35 MPG
Real-world diesel
66L
Tank capacity
£90.29
Full tank (petrol)
28.3p
Per mile (petrol)
Real-World Fuel Economy: The BMW 8 Series achieves an estimated 22 MPG (petrol) and 35 MPG (diesel) in real-world UK driving conditions, accounting for a 12% WLTP real-world penalty.
Forecourt Fuel Cost: Refueling the 66-litre tank completely costs approximately £90.29 (petrol) or £93.79 (diesel) at average UK fuel price rates.
Fuel economy at a glance
22
Real-world MPG
Petrol
26.7
Official WLTP
Petrol
35
Real-world MPG
Diesel
42.8
Official WLTP
Diesel
Annual fuel costs by mileage
| Annual mileage | Petrol | Diesel |
|---|---|---|
| 5,000 miles/yr | £1413 | £923 |
| 7,400 miles/yr(UK average) | £2092 | £1366 |
| 10,000 miles/yr | £2827 | £1846 |
| 15,000 miles/yr | £4240 | £2769 |
| 20,000 miles/yr | £5654 | £3691 |
| Full tank (66L) | £90.29 | £93.79 |
| Cost per mile | 28.3p | 18.5p |
Based on UK average fuel prices: petrol 136.8p/L · diesel 142.1p/L. Prices updated regularly.
How does the 8 Series compare?
Tips to get better MPG from your 8 Series
Utilize the 840d's Eco Pro mode to optimize the coasting engine decoupling.
Maintain active grill shutters clean to preserve the sleek drag profile.
Avoid hard launches; moving 1.8 tonnes of luxury car burns fuel rapidly.
Is the cheaper petrol station worth it?
In a BMW 8 Series achieving ~22 MPG real-world, if you fill 53 litres and the alternative station is 10p/litre cheaper:
£5.30
Gross saving on fuel
£0.85
Cost of 3-mile detour
£4.45
Net saving ✓
You could drive up to 19 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 8 Series?
The BMW 8 Series achieves approximately 22 MPG in real-world petrol driving — around 12% lower than the official WLTP figure of 26.7 MPG due to real driving conditions. Diesel variants achieve around 35 MPG real-world.
How much does it cost to fill a BMW 8 Series?
The BMW 8 Series has a fuel tank of 66 litres. At the UK average of 136.8p/litre for petrol, a full tank costs approximately £90.29. Diesel costs approximately £93.79 for a full tank.
What is the annual fuel cost for a BMW 8 Series?
At the UK average annual mileage of 7,400 miles and current petrol price of 136.8p/litre, a BMW 8 Series costs approximately £2092 per year in fuel. At 10,000 miles/year the cost rises to £2827. Actual costs vary with your driving style and mileage.
Is it worth driving to a cheaper petrol station in a BMW 8 Series?
In a BMW 8 Series doing ~22 MPG real-world, driving 3 miles round-trip to save 10p/litre on a 53-litre fill nets approximately £4.45 after the extra fuel cost. You could drive up to 19 miles before the saving is eaten up. Use the WorthThePump calculator for your exact situation.
How much does the BMW 8 Series cost per mile in fuel?
The BMW 8 Series costs approximately 28.3p per mile in petrol at current UK prices. Over a typical commute of 30 miles per day, that is approximately £8.49 per day in fuel.
What is the WLTP MPG figure for the BMW 8 Series?
The official WLTP fuel economy figure for the BMW 8 Series is 26.7 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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