Tire Pressure - What should it be..really?

[Car Nation Videos]

Lol @ dude that thinks he should be at 50 psi because it says it on the side of the tire. Wow!

For anyone that doesn’t know…you can find your recommended psi inside your door panel or in your owners manual or you can probably Google it. The max psi on the sidewall of a tire is something totally different.

[Robmnrd]

I'll add my two cents just because this is such a long thread about something (relatively) simple - just to complicate things further lol.

If you contact your tire manufacturer and provide them with details about your car and how you use it, they may provide you with a very specific recommendation that is different from the door jam recommendation.

Personal example:

I run Nitto 555G2 up front and 555RII in the rear on my ZL1.

I contacted Nitto and informed them of my vehicle, mods, and how I use it - a nice weather DD that I can afford to "splurge" on, so performance trumps longevity for my tires.

Their recommendation was to inflate the fronts (G2s) so that when warm PSI would read about 35-36 (meaning cold fill is about 32, give or take depending on ambient temps, road temps, etc.) and inflate the rears (RIIs) so that when warm PSI would read about 30 (meaning cold fill is about 27-28, give or take depending on ambient temps, road temps, etc.).

Now Nitto is a more "specialized" brand than most, and my use more closely reflects "performance" even though I do nice-weather DD the car. So what works for me may not work for others.... with that said I have to also point out that the "max" on the side of any tire absolutely is not what ya'll should be inflating to...for so many reasons lol.

[0stones0]

Originally Posted by G8One2

Sorry to bring up an old thread, but I see some confusion here. The manufacturer sets the tire pressure based off of gross vehicle weight. Which is a bit higher than curb weight. There's a difference between curb weight and GVW.

The gross vehicle weight rating (GVWR), or gross vehicle mass (GVM), is the maximum operating weight/mass of a vehicle as specified by the manufacturer[6] including the vehicle's chassis, body, engine, engine fluids, fuel, accessories, driver, passengers and cargo but excluding that of any trailers.[7] The term is used for motor vehicles and trains.

The weight of a vehicle is influenced by passengers, cargo, even fuel level, so a number of terms are used to express the weight of a vehicle in a designated state. Gross combined weight rating (GCWR) refers to the total mass of a vehicle including all trailers. GVWR and GCWR are used to specify weight limitations and restrictions. Gross trailer weight rating specifies the maximum weight of a trailer and the gross axle weight rating specifies the maximum weight on any particular axle.

Curb weight (American English) or kerb weight (British English) is the total mass of a vehicle with standard equipment and all necessary operating consumables such as motor oil, transmission oil, brake fluid, coolant, air conditioning refrigerant, and sometimes a full tank of fuel, while not loaded with either passengers or cargo. The gross vehicle weight is larger and includes the maximum payload of passengers and cargo.[1]

This definition may differ from definitions used by governmental regulatory agencies or other organizations. For example, many European Union manufacturers include the weight of a 75-kilogram (165 lb) driver and luggage to follow European Directive 95/48/EC.[2] Organizations may also define curb weight with fixed levels of fuel and other variables to equalize the value for the comparison of different vehicles.

The United States Environmental Protection Agency regulations define curb weight as follows: Curb weight means the actual or the manufacturer's estimated weight of the vehicle in operational status with all standard equipment, and weight of fuel at nominal tank capacity, and the weight of optional equipment computed in accordance with §86.1832–01; incomplete light-duty trucks shall have the curb weight specified by the manufacturer.[3]

For reference https://en.wikipedia.org/wiki/Vehicl..._weight_rating

So with all of that said, the manufacturer set the tire pressure based off GVW. So unless your running around in a fully loaded vehicle, pushing the maximum GVW, setting tire pressure to what the door sticker says may cause them to be slightly over inflated. I tend to go 2-3 lbs less than what the door sticker says and pay attention to where the tire is wearing when I swap them or rotate them. Doing this should give you a better idea of what tire pressure to actually run on your vehicles. I currently run 34psi cold on my 2014 2SS and see even wear across the treads.

^^^^^
Of all the posts in this thread, this one seems the most useful.