BMW i4 vs BMW 3 Series: Running Costs UK 2026
Last updated: July 2026 · Based on current UK fuel prices
Running a BMW i4 in the UK costs approximately 7.3p per mile on home electricity, compared to 17.4p per mile for the BMW 3 Series on petrol. At 10,000 miles per year with 80% home charging, the BMW i4 saves approximately £726 per year in fuel costs — breaking even on the higher purchase price in around 16.5 years.
At 10,000 miles/yr · 80% home charging
+£726/yr
The BMW i4 saves you approximately £726 per year in fuel costs.
Break-even on the higher purchase price: ~16.5 years
BMW 3 Series fuel cost
17.4p/mile
40 MPG · 153.5p/litre
BMW i4 (home tariff)
7.3p/mile
3.6 mi/kWh · 26.1p/kWh
Annual fuel cost comparison
The table below uses real-world efficiency figures for both vehicles and current UK fuel prices. EV costs assume 80% home charging (26.1p/kWh) and 20% public rapid charging (79p/kWh).
| Miles/yr | BMW 3 Series | BMW i4 | EV saves |
|---|---|---|---|
| 8,000 | £1,396 | £815 | +£581 |
| 10,000(avg) | £1,745 | £1,019 | +£726 |
| 12,000 | £2,093 | £1,223 | +£871 |
| 15,000 | £2,617 | £1,528 | +£1,089 |
| 20,000 | £3,489 | £2,038 | +£1,451 |
Petrol: 153.5p/litre · Home electricity: 26.1p/kWh · Public rapid: 79p/kWh
BMW i4 cost by charging scenario
Charging behaviour has more impact on EV running costs than almost any other variable. Here's how the BMW i4 compares at 10,000 miles per year across four scenarios:
Overnight EV tariff
£194/yr · 1.9p/mile
Standard home (80% home)
£1,019/yr · 10.2p/mile
Mixed (50% home)
£1,460/yr · 14.6p/mile
Public charging only
£2,194/yr · 21.9p/mile
Saving vs BMW 3 Series at 10,000 mi/yr and 153.5p/litre.
Key specs
BMW i4
eDrive40
BMW 3 Series
320i Sport
Get a personalised result for your actual mileage
The figures above use national average fuel prices. Enter your postcode to get live local prices, or adjust the MPG and efficiency for your specific trim level.
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Frequently asked questions
How much does a BMW i4 cost to run per mile in the UK?
At a standard UK home electricity rate of 26.1p/kWh (the Ofgem price cap unit rate for July–September 2026) and a real-world efficiency of 3.6 miles/kWh, the BMW i4 costs approximately 7.3p per mile when charging at home. On a dedicated overnight EV tariff (around 7p/kWh) this falls to just 1.9p per mile. Relying entirely on public rapid charging — which averaged 79p/kWh in mid-2026 — raises the cost to 21.9p per mile.
Is the BMW i4 cheaper to run than the BMW 3 Series?
Yes, for most UK drivers who can charge at home. The BMW 3 Series costs approximately 17.4p per mile in petrol at current UK prices. At home on a standard tariff, the BMW i4 costs 7.3p per mile — a saving of 10.2p per mile. At 10,000 miles per year with 80% home charging, the BMW i4 saves around £726 per year in fuel costs.
How long to break even switching from a BMW 3 Series to a BMW i4?
Based on an estimated price premium of £12,000 for the BMW i4 over the BMW 3 Series, and annual fuel savings of approximately £726 at 10,000 miles per year (80% home charging), the break-even point is around 16.5 years. Drivers covering more miles will reach break-even sooner — at 15,000 miles per year the saving is proportionally larger.
What if I can't charge the BMW i4 at home?
Without home charging, the economics change significantly. Relying on public rapid charging — which averaged 79p/kWh in mid-2026, up sharply from a couple of years ago — puts the BMW i4 at 21.9p per mile — higher than the BMW 3 Series at 17.4p per mile. EV running cost savings are almost entirely dependent on home charging access. Drivers without off-street parking should factor this in carefully.