How much air do I put in my tires. Tire says 44psi max. Door panel says 30psi cold.?

Question

These tires are what was on the car from the factory.

It is a 2006 Kia Sportage. This is a heated discussion between myself and my husband. He says 44psi, I say door panel. I should add he is a Diesel Mechanic, I am a Nurse.

Answer 1

44 is MAX, that means don't go over that or the tire might explode, that doesn't mean that's what it should be ran at ideally. Go by the door panel. Weight of a vehicle matters, heavier vehicles need more PSI when ran on the same tires. Your vehicle is probably light so go with 30psi cold.

Sorry but your husband is wrong, if you were carrying a lot of cargo or weight in the sportage, it would be good to raise the psi in order to keep the same size contact patch. With a light vehicle and 44 psi, you're going to have a very small contact patch which might give you the most miles out of your tires, but will greatly lessen the traction the tires provide, and make it easier to slide, spin and lock up the tires under hard braking... even if you have ABS you still lock your tires up, the computer just releases it to keep traction once it does. It will take you longer to stop on 44psi tires than 30.

The vehicle engineers figure out what psi gives the ideal contact patch size and traction given the weight of that specific vehicle. That's what they put on the door. The tire manufacturers put MAX on meaning don't go over this under any circumstances or the tire could blow, it doesn't tell you what ideal pressure is for your vehicle cause they have no idea what kinda vehicle it's going on.

if your concern is tire longevity - 44psi
if your concern is safety and handling - 30psi

I see where your husband is coming from wanting to put 44psi in though cause that will make the tires last longer, saving you money. You'll also get slightly better MPG, saving you money again, but if you're ever in a spin out or emergency braking situation it could cost you a LOT.

Answer 2

It does not say on the sidewall of the tire to fill it to 44 psi. What it actaully says is what the maximum load and cold inflation pressure limits for the tire are. Litterally the part you are looking at says: "Max Load X kg ( X lbs) at 300 KPo (44 psi) MAX PRESS. What about that makes you think this is a recommendation? All standard load passenger tires say the same thing by the way. Your not reading the whole thing (don't worry, no one ever does). If you do a little more reading on your sidewall you will see where is says "SAFETY WARNING: Serious injury may result from: Tire failure due to underinflation/overloading - follow owners manual or tire placard in vehicle..." So, you should go by what it says inside the door, just like it tells you to do on the tire. Spring, summer, winter or fall the recommended pressure is always the same. Check the tires when "cold", preferably in the morning before driving anywhere as driving creates friction which creates heat which increases tire pressure. To get a good baseline the tires need to be cold.

Answer 3

In my opinion, the rating for tire pressure that is added to the panel on the door is the psi of tires before they are put on the car. The pressure increases dramatically depending on the weight of the vehicle and temperature. If you are adding pressure to the tire while the tires are attached to the vehicle roughly %20 drop in pressure from max. If you are running with tires that signify 44 pounds of pressure max then 36-37 psi is a good number. If you live in an area like me where there are tons of pot holes, the pressure will increase dramatically every time you hit one.

Answer 4

Mr. Knowitall doesn't.

Stand back and look at the information in front of you. If you think about it logically you can answer this one yourself.

The sidewall of the tire says, and I quote "Maximum inflation pressure 44 psi"

The door placard says that tires of the correct size for your vehicle, no matter what brand or model should be inflated to 30 psi cold.

That tire sidewall isn't giving you a recommendation is it? "Maximum" is not synonymous with "recommend" or "inflate this to...". It is in fact a safety warning telling you not to ever exceed that cold inflation pressure. As a point of fact nearly all passenger tires say "maximum 44 psi" on the sidewall. It is just an industry standard that has nothing whatsoever to do with yours or any other car.

The door panel however does give a recommendation - it tells you exactly how much pressure you should use when using any tire of the same size as originally installed on your particular vehicle. And who knows better what that should be then the people who made your car? That same tire might fit dozens of different cars, all with different inflation needs. The tire maker has no way of knowing what kind of car that tire will end up on. If you visit ANY tire manufacturers web site they will also tell you to go by the door placard, not the safety warning on the sidewall.

The job of air in a tire is to support the weight of the vehicle. All tires of the same size, no matter what brand or model have the same inflation requirements, contrary to popular belief. For example, your tire size is probably sized P235/60R16 99T (standard size on Sportage V6 models). At 30 psi any tire of this size has a load capacity of 1,589 lbs. It does not matter what brand or model of tire it is. If it says "P235/60R16 99T" on the sidewall you ALWAYS put 30 psi in it.

A lot people don't get that, mostly I think because they don't understand that the tire sidewall says "maximum 44 psi" not "inflate to 44 psi". That is why you got so many wrong answers to your question.

Over-inflating tires (by doing things like inflating them to the pressure written on the sidewall) can make the tires more susceptible to uneven and premature wear, damage from road hazards such as potholes and it reduces traction. ANd you will hate the ride.

You were right, hubby was wrong, score one for the nurse.

Answer 5

44 is the Max. PSI for the tire cold and will give you a really firm ride, 30 is a minim and a soft ride. most times times the best for you and the life of the tires is somewhere between.

Start at 32 or 34, drive for a while and see how you like the ride. Then adjust the pressure up or down until you get the ride you like.

Answer 6

44 Tires

Answer 7

Follow the door panel. The 44 psi on the tyre merely states the maximum pressure to which you can inflate the tyre. Individual cars have their own calculated pressures to give you the best drive and these must be followed.

Answer 8

Put in 30 psi as the door panel recommends. 44 psi is the max pressure your tires can handle before failure is likely to occur.

Answer 9

Generally car tires are 32-34 PSI. Yes when weather gets cold the pressure will drop a couple PSIs.

Answer 10

I always put in 30 psi in my snow tires for traction in winter and 34 psi in my summer tires for fuel economy and smooth ride ... !!!! NO IF"S ANDS OR BUTS !!!! I do the same with my wife's car and my daughters suv . You could put in more air in the summer and maybe save $ 3.00 in gas for the summer if you're lucky . Easy to remember and these are the safest pressures to use .......