Hi there,
My question is what is the reason for having varying tire pressure in the rear vs front? I have a 2021 Corolla SE and the door sticker mentions front tires should be 33psi while the rear should maintain 30psi. A follow up to that is..
1. Is it better to have all tires at the same psi for this kind of vehicle?
2. What is an acceptable psi increase to put in the tires in the winter?
Thanks!
@txtrickster
If anything there should be a decrease in psi during winter I would think. More flat, more tire, more reaction no? At least in california here with all the rain and wat not. You don't have to worry though as most people just drive. A couple psi off ain't gonna hurt too much + or - as long as it's not a huge discrepancy. Good for you though following the door card.
I suspect it has to do with weight and grip. More weight if front because of engine, thus need higher PSI. Less weight in back, thus lower PSI.
Since tire pressure is based on vehicle weight why should tire pressure be more in Winter?
@jimz
Because tire pressure drops during the winter. Let's say your tire pressure is 35 psi during the summer. When winter comes around, the pressure will drop to like 32-30 psi because cold weather increases air density thus decreases pressure. Pressure is directly dependent on temperature: pressure*volume=[# of moles]*[gas constant R]*temperature. That's why sometimes your TPMS will go off on a cold morning because the tire pressure dropped throughout the night.
Pressure doesn't necessarily have to be more in the winter. You just have to check the pressure and readjust it due to pressure drop in the winter.
I guess Florida does not have enough temperature change to worry about. 😉
I can see how air in a tire can change according to outside temperature. What seems strange to me is that 35 degrees should be 35 degrees regardless of the time of year. I cannot see "adjusting" to a different pressure because of the time of year. 35 in Winter is the same as 35 in Summer. When a tire with 35psi gets cold and that psi drops to 32psi will it not still rise to the correct driving temp when the car starts to roll? But Like I said, I never see that problem here in Florida.
@jimz
Well 32-35 psi is not a big difference in tire pressure anyways. It takes about 15-25 minutes for the tires to warm up when you drive. But I have experienced tire pressure drop while driving. Sometimes when I go driving from the valley to the beach (big temperature difference and also atmospheric pressure difference), the TPMS goes off because it detects a change in tire pressure (in the valley its 35 and when I get to the beach its around 32). Although the tires are hot, the ambient temperature still plays a significant role in tire pressure (atmospheric pressure change is so small that it's negligible). At least in California I experience it sometimes. The moral of the story is...just check your tire pressure once in a while to make sure it's in the desired pressure range. Incorrect tire pressure will cause uneven tire wear.
Tire pressures are to be set "cold" and 35psi is 35 psi regardless of outside temperature so no adjusting is needed.
I guess it takes a thinner turn signal oil for the cold too.