Fuzzo

I know that there was some discussion on what the air pressure in the C's should be. Is everone sticking to the recommended amounts that are posted on the fuel cover... just wondering...

Lynn

I run four pounds over what is posted in the filler door. The ride is a little firmer, but it handles a little better. If you are going to drive in a really sporting manner, add a little more than that.

vinmanc32

But the sedan tire pressure numbers are in the door jam. The numbers in the gas cover are for winter driving, lots of passengers, and other things other than normal everyday driving. I think the front is 32 and the rear is 36. I have a C32 so my numbers may be different than yours but I got it from the door not the gas cover. Good luck to ya.

pixmation

I usually add couple pounds over the recommended pressure. I like it a little firmer and steering is little more responsive.

aborwick

I run 30.5 psi in front and 32 psi in the rear in my C320. The handling is firmer than the recommended tire pressure and the mpg improved about fifteen percent.

MB-BOB

For the C320 Sedan the recommended tire pressures are 28/32 psi (front/rear) as noted on both the driver's door placard and the gas filler lid.

However, I like to use the settings printed on the sidewall of the tire and work from there, instead. This poses a real challenge with the Pirelli P6s that came on my car, because there is (almost) no notation on the sidewalls, at all.

I finally did find the recommended MAX tire pressure, in raised rubber no thicker than .5mm printed in letters no taller than 10 point type right next to the rim. 51 psi. Now, if I ever rub this tire on a curb, this lettering will be gone.

With a max of 51 psiI available, I'm running my tires at 34 psi at all four corners. I don't know why they recommend lower pressures for the front, unless the compression of the added weight of the engine is worth 4 psi on the front axle.

BruNo

Hi

Just had my carlssons installed, what is the correct tire pressure for wheel size 225/40r18??????? My installer doesnt have an idea on the correct inflation figures for my tires.

TimmyC230boy

Well, check your fuel door, it will tell you the proper psi to run with stock tires. But with the new stuff I would inflate to whatever the tire says on it, and monitor the wear on it for about a week or two. if the outsides are wearing more than the center of the tire then you need more air, if the center of the tire is wearing faster than the outsides are then take some air out. Just watch the tires and that will pretty much be a good indication of what PSI you should run.

harpax

I'd say around 34 psi.
I also have 18" and my pressure set ups are 32 psi in the rear and 34 psi in the front.

vadim

Check your tires max. pressure (can be found @ tirerack.com) - and inflate accordingly, not to exceed it, keeping in mind that if you underinflate, you're risking to damage the much more expensive rims due to a shorter tire sidewall. Tire pressure affects handling, so play with it until you find what works best for you. And, like Timmy said, pay attention to the tread wear

BrabusCClass

You must tell us what brand of tire you are using. Tire size and what type of rim doesnt say anything. The make and model, like Toyo Proxy or Perelli P7000 Supersport, etc. Just look at the max on the side of your tire and go 5-10 psi under that. If you dont have enough PSI you will blow your tire up. I guarentee it. I run 40-45 PSI. I've blown a few tires because of under inflation. You have a very thin sidewall and when its low it pinches it and creates a tear. You can figure out the rest.

BlackC230Coupe

i know this wont help BruNo's question but i am just woundering what PSI i should run my tires at i have the stock c7/ rims and tires they are the michilen pilot sport i belive they are 225/45/ZR17 and i was just curious what the tire pressure should be, because i looked on the fuel door and i was not sure if thats for the non c7 rims/tires. so i would just like to know what the pressure in the front and rear should be.

thanks

by the way i live in a warm climate (Florida) incase it matters.

mdp c230k

Don't forget that the temperature change tire pressure. The rating is for STP ( 70degrees F at sea level). If the tire are hot it makes a big difference in their pressure. The formula is (P1/T1)=(P2/T2) the T is measured in Kelvin so add 273 to the Celcius temp. If you dont compensate for the change you will run the risk of being under inflated when the car is first driven. The max pressure rating on the tire is for STP at the rated load of the tire. If there is a difference between front and rear psi on the cars sticker maintain that differential on your setting as well. As stated before, watch the wear patterns too.

BruNo

FYI: I am using Dunlop Formula 901, this tire is not sold in the U.S., second, the sidewalls does not say anything about max or min pressure, no inflation info at all!

Carlsson Germany is telling me to inflate it to 2.7Bar (39psi) front and 3.2Bar (46psi) rear. But i think those will make my car very bumpy. I cant base it on tire wear coz i dont drive d car that much, so itll take me about a year or so to see some wear on it.

mdp c230k

I'll bet the reason for such high pressures is to insure that the tire doesn't compress at all over a pothole so the rim does not get dinged. With that little sidewall it better not flex or the rim gets it!

Smoky

The coupe suggests 32 psi rear and 28 psi front. This is with the C7 Evolution package.

Anybody find improvements by adjusting tire pressure?

Smoky

vadim

I run 37/32 and much prefer it this way.

MBSang

You mean 37 rear and 32 front?

I think I keep mine around that range, I cannot remember exact number now. I noticed better handling instantly.

I think MB suggestion 28 for front is too low.

vadim

Yes, 37 rear/32 front. I prefer it to the high side - gives extra protection to the rims, while still well below the maximum alowed pressure for these tires (51psi/Michelin Pilot Sport).

session

beat me to it! i was just about to post a thread about this. i don't have the C7 package and the michelins are still rated 32 rear 28 front. i run mine 38 rear and 36 front; i like this ride much better and have gotten better gas mileage to boot.

speedfrk

I run 32 all the way around for a good compromise between handling and comfort. If you get the pressure to high, the car tends to "track" or pull on roads with ruts or highways that have had a lot of truck traffic.

Mark08859

For those of you that run higher than 32 psi on your tires, have you noticed premature treadwear in the center of you tire. Or, has it been even?

Also, what advantage does one get by running the rears at a higher pressure than the fronts? If the car was front wheel drive, would someone use higher front tire pressure? Thanks for any info shared.

MBSang

I am always wondering about this, too. I just keep the difference, and equally increased pressure front and the back + 4~5.

Let us know if you why?

session

i run at a higher pressure in the back than the front since MB tells us to do so insofar as performance benefits, i'm not sure.

i run mine 6 psi over recommended levels but i don't have enough mileage on my car to report treadwear at all.

Steve H.

I have been running about 5 lb overpressure on the tires on all 4 of my cars for the past 2-3 years. Each car gets about 10k miles/year. Have not noticed a problem with center tread wear but noticeably improved gas mileage (10%). I run 35 all around in my coupe. Have 7000 miles on the tires with no obvious center wear.