jecy

I bought a 2011 GL450 which i believe it came with the appearance package since It has the 20 inch wheel and the running board. But the label on the driver side says 275/55/19 32 PSI-front 38 PSI-rear. Is this normal for GLs with 20inch? What would be the correct PSI for if have 20's? Thanks

alx

Somebody upgraded the wheels. Running boards can be had with 19" wheels.

mefferso

Had the same thing with my wife's except in the opposite direction. It originally had 19's but 18's were on it when we bought it.

jecy

I guess we follow what is the recommended PSI on the label regardless of your tire size.

alx

actually no... the lower profile the tire the more psi you should run...

jecy

for anyone with 275/50/20, what is the recommended PSI?

Appreciate the help! Thanks

carlosrg

Jecy do you have run flats or non-run flats? A good starting point is 32 Front 38 Rear....

alx

not really. 38 rear all the time on the x164 platform will wear out centers of tires in no time. 38 in the back is only if truck is loaded most of the time which is not true for majority of cases.

i would run the following psi on all four corners on trucks that are regularly driven with 4 or less people on board:

18" - 30-32 psi
19" - 32 psi
20" - 34 psi

would not run anything larger that 20" on those trucks as front suspension as far as i am concerned is weak- especially the steering rack...

so.. in my experience the values above provide the best compromise of tire wear, handling and comfort. on 18" and 19" i would run even closer to 30 psi, but the wheel pressure sensors are hard coded to show low pressure condition at 30-ish so your dash will lit up.

a2j

I run 36-38psi on 18s and 38-40psi on 20s
No wear issues at all. Just my personal experience.

alx

at 38 in the back on 18s on the gl320 you are wearing the rear centers. you might not be noticing it...

a2j

I have over 20k miles on both sets. I just removed one and put the other one on. I would have notice a difference. But if it is such a small wear that it is not noticeable, I don't care

jecy

non-run flat.

Thanks

eric_in_sd

I ran 35 front 40 rear on 265/60-18 and got almost perfect wear across the tread. Usually the back was unloaded. These were Dunlop SP Sport 5000.

It varies by tire, both by maker, by design, and by size. The Ecstas, final weird problem notwithstanding, seemed to want even higher pressures. I was running 38 front 43 rear. One-size-fits-all pressures simply don't work.

Get a caliper - and monitor your tire wear as it depends on pressure.

It's better to err on the side of too much pressure than too little. Tires underinflated wear faster than overinflated by the same amount.

a2j

Does anybody know what the sticker on the door jamb says about pressure for 18s, 20s and 21s? I can't find this in the owner's manual. For 19's it's 32 front and 32/38 rear (unloaded/loaded).

a2j

To answer part of my own question... for 21s it is 35 front 42 rear

edvaru

Picture of my door and fuel door.

a2j

Nice. Thanks! Looks like tire pressure is identical for 19 and 20 in size wheels.