Any recommendations to what tire pressure I should run on 20" wheels?

 

I heard pretty much the same as 19s. Im doing 37 in the front and 41 rears on my 19s and getting 20s soon and asked sum1 wat they were running on 20s and they said the same.

 

I have 20's and running 36 front and 38 rear......for the street.


Stacy

 

Hey Stacy, I'm just curious why you run 36/38 on your 20" rims? I have HRE 20's and I run 33/39 most of the time. I respect your opinion and knowledge, please expand on your tire pressure preference if you don't mind.

Thanks!

Jay

 

should tire pressures be less for 20s???? you guys are running lower than my 19s. Just wondering

 

Hey Jay,

No respect deserved on this one,it is just what I was told to run through a buddy of mine at a local tire shop.....otherwise I have no idea,LOL!
Besides you and I are only different by a few PSI...nothng serious!

No problems so far!

Stacy

 

Light load (1 or 2 people no luggage) pressures for 19s are:

997.1 - 33/39 PSI

997.2 - 34/40 PSI

 

Thanks for the reply Stacy, I appreciate it!

Jay

 

I run 40psi front and back on my 20s. Any reason to run diffrent psi for the fronts and rears? whats the advantage or reason to run 34/35/36/37/38 psi? handle, ride, comfort, any diffrent?

 

You probably have more understeering than you should...

 

are you guys talking about cold tire psi? b4 your start driving around and letting the tires warm up? or is this the psi after youve driven around... started to run 33psi all around on cold, and it would go up to 36/37, then my buddy at a tire shop said run 36-38 cold...

for some reason this whole psi thing is getting on my nerves specially now that i have tpms, so im checking the psi every 5 minutes... and freak out if the psi is 1 or 2 psi diffrent from eachother after i start driving or when i start the car up form sitting over night... is this normal...

do you have to run diffren psi front and back? or is it ok to run the same psi all around? any reason for running less psi in the front??? and more in the backk??

 

door jam is typically fully loaded. Manual will list correct street values and I follow them or very close to, 33/39.

 

The tire pressures indicated are typically for 'cold' tires. Other folks on the thread might be more expert on the norm for 'cold' but I try to do it late in the day and out of the sun in the winter, and first thing in the morning in the morning and out of the sun in the summer (CA Bay Area).
The tire pressure thing does make me a bit crazy - for no good reason. I check and adjust too frequently.
But running a lower pressure in the front, on our cars in particular, makes lots of sense. Far less weight on those tires, the car has a lot of understeer built in and lowering the front pressure will (up to a point) increase footprint and compliance countering the understeer tendencies.
I generally think that 33/39 for the .1 with 19" is a good starting point. I'd be hesitant to go any lower with 20" because there is very little sidewall there to protect the rims from a sharp pothole. That's why adding a bit, though likely sacrificing grip, would be a good idea.
Which are the issues with 20" rims. You generally get a rougher ride, less grip, less compliance, and more rotating mass. However these are not dramatic differences versus stock, but you should just be aware.

 

wow Verde Thanks so much , really apreciate you taking the time to explain all that. Just another curious question for anybody that can anwser... is it odd for the front drivers side tire to always be a few psi's lower than the rest when you 1st get into your car and start it up? Also is it normal for all the the tires to have diffrent psi`s on startup 1/2 psi diffrent but after driving they all start to even out...this is what drives me crazy about the psi`s , im starting to wish i didnt have tpms so I wouldnt lose my mind over it everytime I got in my car/ drove my car...

 

Tires should be same at start up on each side - but TPMS takes some time to get "warmed up" too, so it could read sometimes off by 2lbs at the start but usually settles down in a minute or so. If you set your pressure with a guage, then look at TPMS and make a mental note of how much it differs - mine is really close to what the guage says.

After you start driving, not much point to look at it other than to know you are not losing air rapidly. Friction will change the pressures between tires dramatically - to see this in action, you have take a "play day", set the pressure, then take a drive and monitor what happens: at relatively constant speed and straight roads, the tires come up to operating temp/pressure and hit equilibrium in about 20 min. - even in cold weather - and they gain about 4lbs each and fronts will come up faster on curvy roads. Fronts on the TPMS will continuously vary by as much as 2lb unless you are on long straights.

At any rate, set them cold (68F) and then don't worry about them too much when underway unless you get a "rapid change" TPMS alert.

Recommended pressures are really different for different car/wheel/load combos - I'd say check the manual or the door and go from there.