My car's door sticker says to inflate tires to 33 PSI. I check at home when the tires are cold. Sometimes when I check, the tires show 32 or 31 PSI. Is this considered low and needs me to inflate them? At what point do I absolutely need to pump them back up to 33 PSI?

On the other hand, should I overinflate them to something like 36 PSI such that when it does "dip down" to 32 or 33 PSI, it won't mean my tires are in danger?

1 Answer 1


As far as what is considered low, IIRC, TPMS will indicate low pressure when they are ~5 psi under. Most will also state when they are too far over as well. 31-32 psi is a bit lower than the recommended 33 (obviously), but it's nothing which is going to kill your tires. If I noted mine being there, I'd put it on my list of things to fix and get them at or above the recommended levels. There is nothing which states you must have it fixed when it gets xxx psi below recommended. Just the general guidelines of if it's below what's on the sticker, put some air in it (at least I've never heard of a tried/true number ... there may be recommendations out there, but I believe they are going to be opinions and nothing quite set in stone).

I usually ride my tires a little over the stated amount by 2-3 psi. This ensures I'm always at or above the recommended amount. Beyond that, it gives me two benefits I can state. First, there is a little less rolling resistance, which means I should be getting a little bit better fuel mileage. Second, they give a little less sidewall deflection, which adds to stability.

Something to consider with higher than normal tire pressure, it also decreases the contact patch, which means it decreases traction. This may not be the best situation during the winter months if you drive in snowy conditions or on snow packed roads.

  • Yes. In fact, for driving on snow or mud the door stickers don't really apply at all. The optimum pressure on snow would be something around 10 psi, though that would obviously be a recipe for destroying the tyre when rolling over anything harder. Dec 27, 2022 at 21:49
  • 1
    I'd never run tyres over-pressure - that contact patch is more important than saving a bit of fuel, especially on skinny tyres where the effect is greater. Sidewall deflection is part of the 'normal' tyre contact. Ask any F1 driver if they'd prefer higher pressures ;)
    – Tetsujin
    Dec 30, 2022 at 17:53
  • @Tetsujin - My understanding why they run tires much lower in F1 is not because of the contact patch, but rather because the tires don't support as much weight as a typical road car. Also, F1 tires have very minimal side wall height, so deflection is going to fairly non-existent anyway, especially with the new 18" tires which were imposed in 2022. The old ones were 13". F1 cars rely more on stiction and aero downforce rather than contact patch for it to hold. Here's a pretty good article on the new tires: autoweek.com/racing/formula-1/a38593154/… Dec 30, 2022 at 19:42
  • @Pᴀᴜʟsᴛᴇʀ2 - sure, the new tyres behave differently, but for years on the old tyres the sidewalls were huge compared to a road tyre - it was half the suspension too. The drivers still always want lower pressures than they're forced to have; Pirelli insist on minimum pressures, which make the tyres less grippy, even though they have massive downforce compared to a road car
    – Tetsujin
    Dec 31, 2022 at 16:10

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .