hi everyone,

i just got 4 new hancook ipike winter tires for my 3.0 x type 2004. the tires are 225r45 17. when i look at the gas cap panel, different pressures are mentioned. my tire speed being rated "t", my understanding is that i should be at 30 psi all around. is that correct? can someone enlight me?

thanks❄️❄️❄️❄️❄️❄️

 

Jaguar apparently does not list any "T" speed rated tires in their approved listing of tires, so use the information from the manual as you deem appropriate.

 

ah! thank you so much. your manual is much more complete than mine, which is silent on the tire pressure and refers to the gas cap cover.

from your manual, i'll inflate them at 32 psi all around. thanks again, very belpful

 

x2004, the pressure that you need your tires at is a function of the tire, not what is printed in the owners manual or in the car. The book and/or sticker is true for the factory tires. But, since you have deviated from the factory tires, those kinda become useless information. Probably good for a starting point, but that is it.

The key numbers that I normally start with is the maximum tire pressure the tire can handle and the max weight the tire can handle. In short, if you are running a tire near its max weight limit, then the pressure needs to be up near its max allowable pressure. If you are running the tire at say half of its rated weight limit, then you need to be at around 2/3-3/4 of the max tire pressure. In short, you want to minimize the amount of sidewall flex without the pressure being so high that you are forcing the center of the tire into the road and wearing it out too fast.

The best advice that I can give you is to get your hands on some "sidewalk chalk" (big things of color chalk) and white paper. You will want a bright color like red or green. You are going to take the chalk and put a good layer of chalk on the tread of two tires (1 front, 1 back). You are then going to lay some paper in front of the tires that have chalk on them and roll the car over the paper to transfer the chalk on to the paper. What you are looking for is an exact impression of the tire tread on the paper. If the edges are lighter than the center, your tire has too much pressure in it. If the center of the tread is lighter, then you need to add more pressure. Adjusting the pressure by 2-3 psi is all that may be needed. If you adjust the pressure, chalk the tire(s) up again and check to see you have a nice tread design transfer.

Keep in mind that this should be done with how you normally have the car. You will find that if you suddenly have a full load of people in the car (vice only having yourself in the car), you will want to add some pressure to the rear tires to account for the added weight.

I have some tires that have a max tire pressure of 44 psi and I normally run the fronts at 38 psi and the rears at 35 psi.

 

thank you both panamajag and thermo. from both your replies and looking at the numbers you provided and on the tires, i've finally figured it out. i need 38 psi on the front wheels and 35 psi on the back wheels; which btw improved my mpg right away.

thanks again.