S500 Man

i just put 20 inch tires on my s500 and i want to know the correct tire pressure, i have 40 PSI all the way around currently, because thats what the tire shop said since its a 20 inch tire,275/30/20 in rear, 245/35/20 in front tires, with the 40 psi i feel the bumps way too much, i had 20 inch tire before, and ride was smooth, but i forgot what the tire pressure was.

what tire pressure do you guys recommend on 20 inch tires to still get a soft ride front and rear psi? thanks in advance

ssonss1

i keep them at 42 up front and 38 rear...reason being that the roads here are pretty bad and with higher air pressure theres less chance of the wheels bending...if your roads are okay and not worrying about bending them...lower them to 35 all around you should notice a difference...

Vader55

34 front 32 rear.... you guys are riding on rocks.

S500 Man

is that gonna be ok with dubs benznodubz? 34 front 32 rear

Vader55

yes, I ran that pressure with my 20's and run it now with my 19's... try it... you can also try 36-34 and 38-36 at the most.

S500 Man

thanks ill give it a try/hows the wear on the tires with that pressure?

Dixit

Question why are you folks flipping the tire pressure, in that why you running higher fronts then rears? Ive always ran higher on rears on RWD cars. Im running 34-37 on my 20s right now.

Dixit

icwater

my guess is that big chunk of metal under the hood in the front of the car thats rather heavy

Dixit

That I understand but the Mercedes specs aer 32F 35R, so wondering why Benz recommends that but many of your are flipping it.

Dixit

S500 Man

yea lol kinda confused me too?i think its maybe since theres less weight in rear, it makes it so the tires are little softer and grip a little better

fusion2007

where is newton?? he used to post all over this forum whenever there was a thread about tires or even in general!!!

my06clk

Those specs can't apply to a +3 tire.

Dixit

I understand that, what Im still asking why people are flipping it? Normally I take the OEM specs and then bump then up by 2-4psi when I go bigger in size.

Tirerack recommends going up 1psi for each inch of rim size increase.

Sounds like one could just find out what the S63/65 has their set at since they use 20s.

Dixit

AMG_Mike

doesnt the rear tire heat up quicker than the fronts because the power is put down in the rear? I have my 20s at pretty high pressure levels compared to you guys. Im running a 40 up front and a 38 in the back. I believe the tire states to not exceed 45 psi? With all my driving, the TPMS has never peaked past 45 when the tires were inflated at a cool 38-40. But again, i live in So Cal and not the piping hot dessert of NV or AZ.

S500 Man

your car is fricking hott amg mike i need to lower mine like yours.

jamsline

I notice most of you are not telling the year of the vehicle. Does it matter? I have a tire pressure monitor on my car that tells me that the pressure is incorrect. I currently have 34 front and 35 rear. I know I need more air since I'm running on 18" What is the correct pressure for 18" and 20" since I have both sets of tires?

220lover

38 rear 34 front. I would adjust accordingly if 4matic.

jamsline

I was told by the firestone dealer that it should be 30 front and 33 rear! I haven't gotten a tire pressure warning since they adjusted it and I don't have a 4matic.