The Mercedes-Benz SLK-Class does 21.5 mpg combined (18.8 city, 26.2 highway), which works out to about $1,786 a year in fuel at $3.20 a gallon and 12,000 miles. Engine choice matters more than you'd think: 2L 4-cyl does 27 mpg while 5.4L 8-cyl does 16.2 — a difference of $948 a year. Against other V6 cars it sits above the average of 19.9 mpg.
Every Mercedes-Benz SLK-Class engine, compared
Gas mileage on the Mercedes-Benz SLK-Class ranges from 27 down to 16.2 depending on which engine sits under the bonnet — a spread of $948 a year across 8 versions of the same car. Picking the right one often saves more fuel than picking a different car altogether. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 2L 4-cyl | 24 / 32 | 2016–2016 | $1,422 | |
| 1.8L 4-cyl | 23 / 32 | 2012–2015 | $1,477 | |
| 3.5L 6-cyl | 20 / 27.1 | 2005–2016 | $1,692 | |
| 2.3L 4-cyl | 19.5 / 26.7 | 1999–2004 | $1,722 | |
| 5.5L 8-cyl | 18.2 / 27 | 2010–2016 | $1,811 | |
| 3L 6-cyl | 18.4 / 25 | 2006–2011 | $1,864 | |
| 3.2L 6-cyl | 18 / 24.3 | 2001–2004 | $1,892 | |
| 5.4L 8-cyl | 14 / 20.4 | 2005–2009 | $2,370 |
What that actually costs
The Mercedes-Benz SLK-Class burns a gallon every 21.5 miles, so 12,000 miles takes about 558 gallons a year. At $3.20 that is what the table below adds up to.
| Measure | Value |
|---|---|
| Cost per mile | $0.149 |
| Fuel per year | $1,786 |
| Fuel over five years | $8,930 |
| Against other V6 cars | −$144 a year |
| EPA's own estimate | $3,654 a year |
City or highway — who is this car for
The Mercedes-Benz SLK-Class gives up 7.4 mpg the moment you leave the motorway — 26.2 out there against 18.8 in town, a 39% drop worth $577 a year. A wide gap punishes stop-and-start traffic; a narrow one means the car doesn't care where you drive it.
| Measure | Value | Reading |
|---|---|---|
| City | 18.8 mpg | $2,043 a year if you only drive in town |
| Highway | 26.2 mpg | $1,466 a year if you mostly commute |
| Gap | +7.4 mpg (39%) | Wide — this car dislikes traffic |
How the SLK-Class changed over the years
The SLK-Class peaked in 2016 at 24.3 mpg (21.3 city, 29.3 highway) and was at its thirstiest in 2005 at 17.5 — 6.8 mpg apart, or $614 a year in fuel between buying one year and the other. The 2016 car does 24.3. Jumps usually mark a new generation or a new engine; dips often mean a heavier body or added all-wheel drive.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2016 | 21.3 / 29.3 | 3 | $1,580 | |
| 2015 | 21 / 29.3 | 3 | $1,600 | |
| 2014 | 21 / 29.3 | 3 | $1,600 | |
| 2013 | 21 / 29.3 | 3 | $1,600 | |
| 2012 | 20.7 / 29.7 | 3 | $1,620 | |
| 2011 | 19 / 26 | 1 | $1,829 | |
| 2010 | 16.5 / 24 | 2 | $2,021 | |
| 2009 | 16.5 / 24 | 2 | $2,021 | |
| 2008 | 16 / 22 | 2 | $2,133 | |
| 2007 | 16 / 22 | 2 | $2,133 | |
| 2006 | 16 / 22.5 | 2 | $2,076 | |
| 2005 | 15.5 / 21.5 | 2 | $2,194 | |
| 2004 | 18.5 / 25 | 2 | $1,829 | |
| 2003 | 18.5 / 25 | 2 | $1,829 | |
| 2002 | 19 / 25.5 | 2 | $1,786 | |
| 2001 | 19 / 26 | 2 | $1,745 | |
| 2000 | 20 / 27 | 1 | $1,745 | |
| 1999 | 19 / 27 | 1 | $1,745 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 38 EPA ratings of the Mercedes-Benz SLK-Class — 8 engines across 1999–2016. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $3,654. Full method.
Frequently asked questions
What mpg does the Mercedes-Benz SLK-Class get?
21.5 mpg combined on average — 18.8 in the city and 26.2 on the highway, per EPA ratings across 1999–2016.
How much does a Mercedes-Benz SLK-Class cost in fuel per year?
About $1,786 at 12,000 miles and $3.20 a gallon — roughly $8,930 over five years, or 0.149 dollars a mile.
Which SLK-Class engine is the most economical?
The 2L 4-cyl at 27 mpg, against 16.2 for the 5.4L 8-cyl — a difference of about $948 a year.
Is the SLK-Class good on fuel compared with similar cars?
Against other V6 cars it sits above the average of 19.9 mpg, computed across 4940 ratings.
Are these real-world SLK-Class figures?
No — they are EPA laboratory ratings, the same ones printed on the window sticker, and EPA's own annual fuel estimate for the Mercedes-Benz SLK-Class is $3,654 against the $1,786 we compute at 12,000 miles. Expect a little worse in practice: the spread between the 27 and 16 mpg versions of this car is smaller than the spread between two drivers of the same one.
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