A New tire question

[boubou]

I realise wrangler HP 20" tires aren't the best for towing but...
When I left, I had 37 psi in tires and after 2 hours of driving (55 mph/hr), psi was up to 42. Is that normal? Tires are rated for a total of 45 psi.
I will get new tires in the spring, but curious.

[Jeep4Two]

Originally Posted by boubou

I realise wrangler HP 20" tires aren't the best for towing but...
When I left, I had 37 psi in tires and after 2 hours of driving (55 mph/hr), psi was up to 42. Is that normal? Tires are rated for a total of 45 psi.
I will get new tires in the spring, but curious.

Typically the max air pressure rated at cold, so increases in pressure under operating temp should be factored in. I could be wrong so hang tight for more experienced members to reply.

[Triguy]

The short answer is, yes, tire pressure will rise as you drive.

But your tires were probably getting a little too hot from the underinflation (37psi was too low to begin with). Fill them to their rating, which in your case is 45 psi (cold).

[boubou]

Originally Posted by Triguy

The short answer is, yes, tire pressure will rise as you drive.

But your tires were probably getting a little too hot from the underinflation (37psi was too low to begin with). Fill them to their rating, which in your case is 45 psi (cold).

In door it says inflate to 35 psi cold and max pressure 45

[Jeep4Two]

Originally Posted by boubou

In door it says inflate to 35 psi cold and max pressure 45

I'm assuming you are referencing the tires on your toe vehicle. Remember that when towing, or carrying near max payload many manufacturers recommend higher tire pressures (cold). Check the owners manual and door jamb for recommended cold pressure at max payload.

[boubou]

Ah I see. Ok thank you

[Triguy]

Originally Posted by boubou

In door it says inflate to 35 psi cold and max pressure 45

Sorry - I should have asked for more information. I assumed (and see where that got me ).

The first number is the proper tire pressure for your vehicle - the "recommended cold inflation pressure."

This on maximum inflation pressure might help.