CLK-1

For my 2004 CLK320 coupe. I am running a set of 17-inch Pirelli Pzero Nero M&S purhcased from Tirerack a while ago. They are 225/45/17 and 245/40/17, mounted on AMG Double-Spoke 203.

What tire pressures do you recommend?

tampaclk

call the rack, they'll let you know.

MarcusF

I wrote an article about this ages ago. Without rewriting the whole thing, no one can give you the optimum tire pressure for your car. Every car is different. Tire brands, sizes, wheel sizes, vehicle weight, alignment specs, and suspension components all add up to make each car unique. If each car carries it’s weight in a unique fashion, then it makes sense that the best tire pressures may vary from car to car. That being the case, the optimal tire pressure is derived from “reading” the tire.

I know of two ways to “read” a tire and determine the optimum tire pressure. The best method that I know of requires the use of a pyrometer. A pyrometer is a temperature sensing tool and it will save you money in the long haul. Use it right and you'll have the correct amount of air in each tire (they can be different from side to side as well as back and front), and it can pay for itself because you’ll get more life out of your tires. If you're interested in what a pyrometer can do, post back and I'll try to answer your questions.

If you drop a grand in tires every eighteen months on street tires, but still think that a $100 or so for a pyrometer is too much, here is the two-dollar chalk method.

At the track, or on your favorite curvy stretch of road, take some chalk and mark all four of your tires. Make the mark across the tread portion of the tire, around the edge, and about an inch down the sidewall (about where the lettering starts on the side of the tire).

After making a few passes through both left and right hand curves, pull over and check the tires. What you hope to see is all the chalk rubbed off the tread on the tires, and almost all of it still on the sidewalls. How much is almost? If you've only rubbed off one sixteenth of an inch of the chalk on the sidewalls, that's good. If any chalk remains on the outer edges of the tread, you have too much air pressure. If the chalk is rubbed off down to the lettering on your tires, you've got way too little.

That's as close as the chalk method gets. It lets you know that you're not at the extreme end of either spectrum.

Lastly, if you're just using your car for regular commutes back and forth to the office, use whatever pressure is stated in the owner's manual. If you do that and remember to check it every time you do an oil change you'll probably be fine.

CLK-1

I agreeand this is exactly why I posted this question here in the CLK section. I hope other CLK320 folks can give me some insights.

I am not aggressive driver and for 80% of the time, I am on the highway doing 120/130 KMH. I currently set the tire pressues to 31F/33R.