Hi, I am thinking of buying a 2002 or 2003 CLK 320/430 Convertible.

Any special things I need to look at?
Also, the manual says Premium gas only. However, most automotive websites say that all modern cars automatically adjust to regular, and really do not need premium.
Any thoughts on that?

Thanks!

Berrie

 

Berrie, The CLK engine is built with approx. 10-1 compression ratio for power, which fundamentally requires a higher octane to prevent predetonation.The combustion derived from the 10-1 ratio is the physical source of theCLK's power. One of the notable aspects of theCLK engine is that offers high performance compression AND a high degree of reliability, where as in some makes you have to choose between the two.

Now no two tanks of gas will be the same, and there's no guarantee you are even getting 93 octane when you pay for it, but if your engine "knocks" due to low fuel octane, you know it causes a great deal of strain, heat, and unecessary wear onthe engine.The CLK is right on the edge regarding fuel requirements and that would apply to any engine with 10-1 or more.

Of course there are a lot of other cars that have much lower compressions, which will not benefit from higher octane fuel, and makes little difference either way.I think the civic was around 8 or 9 . So it depends mostly on the compression ratio.

With 10-1 ratio, low octane (88-87) is simply the wrong fuel.

 

I agree with BlueSilver, dont even try to put regular gas. The high compresion will kill the motor, if you also use regular you will get less gas mileage so the money doesnt add up pay 20-25 cents a gallon more for 15 gallons for a 3.00 savings on a full tank. And you will def get 2 mpg better on the clk. so if you get 20 miles a gallon highway on regular you can get 22 mpg on premium so youll prob get 35 miles on that extra 3.00 of gas. But y do that to your car, its just not right in the long run.