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Two sheets, one bench · Subcompact Cars

M440i xDrive Coupe vs 430i xDrive Coupe

BMW M440i xDrive Coupe against BMW 430i xDrive Coupe, two test sheets laid side by side.

BMW M440i xDrive Coupe

29
MPG · $1655/yr
vs

BMW 430i xDrive Coupe

30
MPG · $1600/yr
More efficient

The gap, in fuel

$55a year between them

The BMW 430i xDrive Coupe is more efficient — 30 MPG against 29 for the BMW M440i xDrive Coupe. Over 15,000 miles a year at $3.20 a gallon that is a saving of about $55 a year, or $276 over five years.

SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026

How this is worked out

  1. Start from the EPA combined figure for the model year — a laboratory test cycle run to a fixed procedure, not a road result. Where a year sold several engines or drivetrains, the trims are averaged and the trim count is printed beside the row so you can see how much averaging is behind it.
  2. Fix a pump price. This site keeps one reference price, $3.20 a US gallon, fixed JUL 2026 and printed next to every dollar figure it produces. It is an assumption with a date on it, not a quote — put your own price in.
  3. Fix an annual distance. Every annual figure on this site uses 15,000 miles a year, roughly the US average. A cost per year with no stated distance is not a number, it is a mood.
  4. Divide distance by economy for gallons, multiply by price for the year's fuel, divide price by economy for one mile. The per-kilometre line is that last figure divided by 1.609344 — the same money, in the unit most of the world drives in.
  5. Stop there. No depreciation, no tyres, no insurance, no servicing. This is the fuel line of the ledger and it is labelled as one; depreciation usually dwarfs everything on it.
gallons/yr = miles/yr ÷ MPG
fuel  $/yr = gallons/yr × $/gal
cost  $/mi = $/gal ÷ MPG
cost  $/km = cost $/mi ÷ 1.609344

The full method, the licence note, and what a test figure cannot tell you →

Both sheets, line for line

BMW M440i xDrive CoupeBMW 430i xDrive Coupe
Combined economy 29 30
Best year on record 29 30
Worst year on record 25 24
Average across all years 26.9 27.5
Fuel per year 1655 1600
Gallons per year 517 500
CO₂ g/mi 300 294
Model years tracked 7 11
ClassSubcompact CarsSubcompact Cars
Years2021–20272017–2027

Highlighted cells are the better of the two on that measure. Fuel costs at $3.20/gal over 15,000 miles.

SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026

Questions asked across the counter

Which is more fuel efficient, the BMW M440i xDrive Coupe or the BMW 430i xDrive Coupe?

The BMW 430i xDrive Coupe is more efficient — 30 MPG against 29 for the BMW M440i xDrive Coupe. Over 15,000 miles a year at $3.20 a gallon that is a saving of about $55 a year, or $276 over five years.

Which is cheaper to run, the BMW M440i xDrive Coupe or the BMW 430i xDrive Coupe?

On fuel alone, the BMW 430i xDrive Coupe: $1600 a year against $1655 for the BMW M440i xDrive Coupe, both at $3.20 a gallon over 15,000 miles — an assumption fixed JUL 2026. Fuel is the only line being compared: depreciation, insurance, tyres and servicing are not in it, and they routinely matter more than this gap.

Is the difference big enough to change the decision?

Across five years of that same driving the gap comes to about $276. That is real money, and it is also roughly what one year of depreciation does to a new car — so treat it as one line in the ledger rather than the whole argument.

Both entries carry the full year-by-year history and the pump-price ledger. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.

See all 10 sites in this family, with what each one answers

Published by

Amit Sharma

Auckland real-estate agent and marketer. Builds free, sourced data tools.