slammedcclass

What are you smoking???

And Yes there is a tire pressure thing

il_dirigente

ok, so i do my 20,000 mile checkup at dealership a. Oh, you have bent rims, that is why your ride feels like you are riding on lipsided tires, give us 1000$ and we will fix it.

So i am like, whatever, let me drive with it and i will see... so in the meantime, i take it to dealership B. i did not tell them what A said, so they take two days, call me up, "the technician said the pressure was too high in your tires. so he lowered it, and then took it for a test drive and it seems to be fine now." i am like.. "uhhhhh, ok."

so i go down, pick it up, drive it home, and it is better, but i can feel the vibration, shimmy, shake, whatever you want to call it.. in the back of my seat now instead of the steering wheel AND seat.

i am just wondering what the guy at B actually did? I mean, i have NEVER heard of tire pressure affecting the ride that much.. especially when it was only 8PSI over, and my tires can handle 20psi over the suggested.

thanks.

ctC230K

tire pressure is a vast right wing conspiracy that originated around 1998 from the bush administration when large auto companies lobbied the white house to push for increased tire pressure in luxury automobiles.

it's a bunch of baloney you don't need this so called "tire pressure". get rid of it!

tommy

Stock rims and tires at 40 could feel that way.

IMHO, the best thing to do is take it to a local aftermarket shop that knows what they're doing and have them check your rims.

If you're feeling some vibrations, it's either your paranoia or an actual problem. A dealership isn't the best place to get a good opinion from. Besides, if it is a bent rim, it'll be very hard to get that warrantied, as they'll most likely say that it was not defect-related, and you'll be hard-pressed to change their minds.

FashionCore21

I just put some 19" amg replicas and was wondering what the correct tire pressure would be for the smoothest ride POSSIBLE on a 19 and even wear on the tires? Should I still use the chart in the door jam ? Thanks for any help.

jlee-

whats your tire size?

FashionCore21

Kuhmo ecsta staggerd setup 265/30/19 rear and in the front 235/30/19

gaogi

Just wondering, do you rub in the rear with 265 tires?

FashionCore21

No rubbing yet but have not put 4 people in it yet eiter so well see.

///M3N

I wouldnt follow the chart on the door since that recommendation is for the stock wheels and tires, I honestly haven't looked at the tire pressure chart over there. I just pumped some air yesterday and I'm using the tire pressure recommendation stamped on the tire itself, mine says not to exceed 40 psi. I did about 35 psi. With a low profile tire I don't think it's a good idea to run the tires soft. Driving on 19"s for a couple months now, they're not as smooth as the stocks but it's not bad at all. I have 265's at the back also, mine rubs, even by myself when I hit a hard dip on the road.

gaogi

Have you trimmed off the plastic tabs on the inside of the wheel well? I'm about to trim them off, but if they don't help, then I won't bother...

rlee02135

can you post a pic of the tabs?
i couldnt find them

amdeutsch

Someone posted a thread in the SLK forum where he measured temperature on the tires to arrive at the correct pressure. TOO LAZY TO STFF.

Tirerack recommends pressures on their website for this as well as gives reasons for it all.. I also wouldn't follow the printing on the side of the tire. It all depends on your load, speed, etc.; i.e. weight, temperature, volume.

P.S.
Ask our super mod VRAA as he is right now studying these gas laws in college.

FashionCore21

so I have no idea what the correct pressure is now someone please help us!!!

jungle666

Hello, i've been reading to try to find out what is the best tire pressure for my 2007 C230 sport with stock Michelin tires. If i look on the side of the door it says 28f / 32R. Now if i look on my tires it says a maximum of 51 psi. When i bought the car from a mercedes dealer it came with 33f and almost 40R . I've also read people put more pressure in the front. I am kinda confused here. I need some recommendations. Thank you for any help.

blueserenity777

I normally get mine done at mercedes for free..Gas stations sometimes have uncalibrated air pressure pumps..my service guy says to bring it in whenever and they will check on the pressures for free..since their pumps gets calibrated regularly so they know exactly what it is required..far better than me fumbling about and getting everything wrong..and u know what happens when you get the pressures wrong..handling,consumption,tyre wear all come into play..

johnp

I use a gauge at least once a month (first thing in the morning when tires are cold) and put in 2 lbs more than recommended in each tire

kickR

go with 28/32 ... thats the optimal pressure tested by mercedes i guess.

diamondblak05

I usually put 35psi up front and 40psi in the rear when cold on my 18" wheels. I think the factory recommendation is too soft.

alboogiee

Agreed, I add a little more too with the stock 17s.

I invested in a digital gauge to ensure accuracy, I also (try to) check the pressure once a week. I do have the passive TPMS but it has never thrown a fault, but when checking pressure I will notice changes +/- 3-5PSI.

Moviela

The pressure listed on the side of the tire is the MAXIMUM for that tire. It is usually much more than the running pressure. If you over inflate your tires, they will wear faster in the center. If you neglect your tires, and allow them to run under inflated the edges will wear faster. Properly inflated tires will run cooler, with greater gas mileage. There are exceptions to the placard values, and they are explained in the manual.

A digital pressure gauge is not more accurate. A calibrated gauge is more accurate. Most digital gauges cannot compensate for altitude pressure variations. A $ 30 Flaig gauge is perfect for the glove box. They are German made, read in Lb/sq-in and Bar, and are available from our sponsor Performance Products. I have used this gauge for ages, and they remain accurate for decades. With the price of a set of tires around $ 1,000. one of these is very cost effective.

http://www.performanceproducts.com/p...aig+Tire+Gauge

You can increase the life of your tires and rims by not filling them with air. Nitrogen is in tires of aircraft, race cars, and Costco shoppers. Look for the green valve caps, those tires are filled with inert Nitrogen.

BabyBenz6spd

Sticker says 28/32, I run with 30/34. The car is stiffer and handles better.

drexappeal

I never, ever go by what Mercedes indicates. I always go by what it says on the actual tire. Majority of aftermarket tires are 50 max, so I usually go with 40/44, since majority of my drives are not very long distance (70 miles at the most). If I go for a long trip (i.e. Vegas, Nor-Cal, San Diego) that's between a 2-6 hour drive away from LA, I usually bring it down to around 32/36 w/ the assumption that the tires will heat up and expand.

drexappeal

I never, ever go by what Mercedes indicates. I always go by what it says on the actual tire. Majority of aftermarket tires are 50 max, so I usually go with 40/44, since majority of my drives are not very long distance (70 miles at the most). If I go for a long trip (i.e. Vegas, Nor-Cal, San Diego) that's between a 2-6 hour drive away from LA, I usually bring it down to around 32/36 w/ the assumption that the tires will heat up and expand.

Boom vang

Go by what the car company suggests. Tons of research has gone to what is the optimal for the best handling

The number on the sidewall is the maximum that the tire will allow but is not the optimal for your car. Because all cars are different weights the pressure has to be adjusted accordingly. Imagine if our car was 1000lb lighter our pressures would be much lower for the same size of tire.

Higher pressure does not equal better handling. F1 cars have a pressure around 8 to 14psi.


By adjusting pressures you can dial in more understeer or more oversteer

Running at very high pressures will have a much harsher ride.