I kept my 20" wheels/tires

[20ducks]

When I bought my S650 I realized it came with 19" wheels and tires unlike the 20" I had on my S550. So I kept a set from the S550. My question is: what is the inflation rate for the 20" that will soon be mounted on my S650? (btw, I was told not to use rates that my be posted on a tire sidewall.)

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[Wiley Marmot]

There can't be much weight diff between your 550 and 650. If it were me; I'd start with what ever pressure/s you were running on your 550 and go from there. Keeping a close eye on tread wear pattern and ride quality. Good luck.

 

[Sofa King]

The 20 inch tires (optional on S650) have a door placard pressure rating of 36 psi.

 

[Magic88]

That is part of the problem: The s550 wheels/tires have only 22psi now.

Run it up to 32 psi, and go from there

 

[20ducks]

The 20 inch tires (optional on S650) have a door placard pressure rating of 36 psi.

That is exactly what I am looking for....Thank you!

 

[goodlettjr]

PSI on the door is OEM tire specific. Size of tire, tread wear, max PSI, and etc all have a play in the PSI to run for the tires you have.

 

[goodlettjr]

PSI on the door is OEM tire specific. Size of tire, tread wear, max PSI, and etc all have a play in the PSI to run for the tires you have.

Oh and I meant to add, 22psi sounds low for daily driving to me. A quick google search will give you some examples of tire wear, but look for faster wear on your 20s on the inside or the outside.

Inside wear will represent that you have too high of a PSI. Outside edges will represent that you have it too low. Recommend getting a tire depth gauge to check that. By the time your eyeball recognizes it, it’s too late.

Also can ask your local tire shop.

 

[20ducks]

Forget my comment regarding 22lbs inflation.
I got the 20" tires/wheels on my car and inflated them all to 34lbs. I drove around at no more than 55 mph for 1/2 hour or so. They went from 34 up to 37. I've never monitored my tires and I'm not sure if the increase is normal or should I be concerned?

 

[Magic88]

Forget my comment regarding 22lbs inflation.
I got the 20" tires/wheels on my car and inflated them all to 34lbs. I drove around at no more than 55 mph for 1/2 hour or so. They went from 34 up to 37. I've never monitored my tires and I'm not sure if the increase is normal or should I be concerned?

totally normal, driving causes heat, they'll go up in pressure. Parking it in shade or the garage, they'll go back down in a couple of hours or overnight.

 

[Rocket Man]

by the way, the pressure listed on the tire sidewall is the max pressure allowed, not a sugested inflation pressure.

 

[Sofa King]

Forget my comment regarding 22lbs inflation.
I got the 20" tires/wheels on my car and inflated them all to 34lbs. I drove around at no more than 55 mph for 1/2 hour or so. They went from 34 up to 37. I've never monitored my tires and I'm not sure if the increase is normal or should I be concerned?

Sounds about right...

 

[20ducks]

Will someone post a photo of a S550 with 265/35 20 tires with the same info as the Tire and Loading Information I posted please.

 

[ridgebackpilot]

Here you go: 2025 S650 GT Premium with 20-inch OEM tires:

 

[Farmer Fran]

My 650 with 265/35R20 says 36 like posted above. 20s are 36psi

 

[Starship Enterprise]

Fun fact….Also remember that for every 10˚ F drop in temps your tires lose 1 lb. of pressure.

So if you have them properly inflated during a 90˚ summer, yes they can drop 6 lbs of PSI when you see 30˚ in Winter.

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