Dumb tire pressure question.

[dugans]

^^Yep, used a spray bottle and a dry parking lot back in the day to get my pressures right for a 33x12.50 on a 15x10 rim. :mrgreen:

Don't think I've heard of that trick for 30 years or so.
I feel a wave of nostalgia kicking in.

 

[nightcrawler48]

I may be out to lunch here but this is what I do. Generally speaking I don't use the oem supplied brand/size when I have to replace tires. If it is not shown on my bill/invoice, I ask the tire dealer to record the front and rear pressures they used on the bill/invoice. Then if I have any issues with a tire I can show them the pressures they used and I follow what they used. Before you say most of these guys don't know what they're doing anyway, I buy my tires from a long established company who deal in everything from ATV to log skidder tires and everything in-between. And, they want to do it right the first time so they don't have to deal with you coming back for warranty. Just my $0.02.

 

[Col_Sanders]

^^Yep, used a spray bottle and a dry parking lot back in the day to get my pressures right for a 33x12.50 on a 15x10 rim. :mrgreen:

If you're running stock wheels and tires on your vehicle, door jamb is usually the best bet except on a HD truck. Running full pressure in the rear of a HD truck is probably going to give you a crap ride and bad wear on the rear tires if you are driving unloaded so chalk test is helpful for determining pressure you should run. You'll most likely have to deal with annoying TPMS light though.

If you're running aftermarket wheels and/or tires, do chalk test to find correct pressure, especially if you're using a different load rated tire than OE. I put a set of load range D 37s on my Jeep. It came with load range C tires from the factory. Door jamb says 37 psi IIRC. 37 PSI on the new tires rides harsh and i had about 2" on each side of the tire not touching the ground. Looks like ~28psi to get full contact patch.