Mercedes-Benz CLS550
What it costs to keep fuelled
$2,286a year, fuel only
The 2018 Mercedes-Benz CLS550 is EPA-rated at 21 MPG combined (18 city / 26 highway). Over 15,000 miles a year that is about 714 gallons, $2286 a year in fuel, or $0.152 per mile at $3.20/gal.
Across its full 2007–2018 run it averages 18.5 MPG, improving by 5 MPG over 12 model years.
The band is how far one gallon carries it: 21 of the 60 MPG this scale runs to. The square tick is the compact cars average, 26.6.
- Fuel, per year
- $2,286 at 15,000 mi
- Per mile
- $0.152
- Per kilometre
- $0.095
- Gallons burned/yr
- 714
1 mile = 1.609344 km · fuel at $3.20/gal, fixed JUL 2026
Test figure — not a road resultSOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
How this is worked out
- 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.
- 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.
- 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.
- 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.
- 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 →
Re-run the ledger at another pump price
Every line above rests on one pump price. Here is the same entry re-costed at six others, because the price is the part that changes while the test sheet stays put.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.119 | $1190 | $1786 | $2381 |
| $3.00/gal | $0.143 | $1429 | $2143 | $2857 |
| $3.20/gal | $0.152 | $1524 | $2286 | $3048 |
| $3.50/gal | $0.167 | $1667 | $2500 | $3333 |
| $4.00/gal | $0.190 | $1905 | $2857 | $3810 |
| $4.50/gal | $0.214 | $2143 | $3214 | $4286 |
| $5.00/gal | $0.238 | $2381 | $3571 | $4762 |
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
The whole service history, sheet by sheet
12 model years on file. Read down the combined column: a nameplate that got heavier shows it here long before any brochure admits it.
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2018 | 21 MPG | 18 | 26 | $3650 | 425 | 1 |
| 2017 | 21 MPG | 18 | 26 | $3650 | 425 | 1 |
| 2016 | 20 MPG | 18 | 26 | $3850 | 433 | 1 |
| 2015 | 20 MPG | 18 | 26 | $3850 | 433 | 1 |
| 2014 | 20 MPG | 17 | 25 | $3850 | 443 | 1 |
| 2013 | 20 MPG | 17 | 25 | $3850 | 454 | 1 |
| 2012 | 20 MPG | 17 | 25 | $3850 | 444 | 1 |
| 2011 | 16 MPG | 14 | 21 | $4800 | 555 | 1 |
| 2010 | 16 MPG | 14 | 21 | $4800 | 555 | 1 |
| 2009 | 16 MPG | 14 | 21 | $4800 | 555 | 1 |
| 2008 | 16 MPG | 14 | 21 | $4800 | 555 | 1 |
| 2007 | 16 MPG | 14 | 20 | $4800 | 555 | 1 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
Marked against the rest of the compact cars bay
Among the 227 compact cars models tracked here, the Mercedes-Benz CLS550 ranks 164 on current figures, against a class average of 26.6 MPG — the square tick on the gauge above.
Closest more-efficient alternatives in the same class: Chrysler LeBaron (21.3), Chrysler Sebring Convertible (21.3), Ford Tempo (21.3), Mercury Topaz (21.3), BMW 525i (21.5).
Tailpipe CO₂ is rated at 425 grams per mile, which works out to roughly 6.4 tonnes a year at 15,000 miles.
Questions asked across the counter
What MPG does the Mercedes-Benz CLS550 get?
The 2018 Mercedes-Benz CLS550 is rated at 21 MPG combined by the EPA — 18 city and 26 highway. Across all 12 model years in the database it averages 18.5 MPG, ranging from 16 to 21 depending on year and trim.
How much does a Mercedes-Benz CLS550 cost in fuel per year?
At 21 MPG and 15,000 miles a year, it burns about 714 gallons — roughly $2286 a year with fuel at $3.20 a gallon, or $0.152 per mile. The EPA's own published annual figure for the 2018 model is $3650.
Has the Mercedes-Benz CLS550 become more efficient over time?
Yes. It has gone from 16 MPG in 2007 to 21 in 2018 — an improvement of 5 MPG, or 31% across 12 model years.
Is the Mercedes-Benz CLS550 efficient for its class?
It ranks 164 of 227 in the Compact Cars class on current figures, against a class average of 26.6 MPG. That is 5.6 worse than typical for the class.
Pull another logbook off the same shelf
Same class, nearest economy first — the ones a buyer is genuinely choosing between.
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
Cost per mile, per kilometre and per year are computed at a reference price of $3.20 a gallon over 15,000 miles, fixed JUL 2026 — set your own pump price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.
