help! i have the wrong tyres so what tyre pressure do i use??

Question

my escort encore should have 14 inch wheels but i found out recently that it for some reason has 13s on it.at the mot it needed new tyres and i got the work done by someone i know (which is cheaper but not always as good!)he didnt have any 14s so he put 2 ford 13s on the back and had to put 2 renault 13s on the front as the new break pads wouldnt fit with the ford 13s!!all a bit confusing i know and i intend to get it sorted as soon as i can afford to but for now i just really need to know what pressure i should have in the ones iv got??thanks in advance!xx

Answer 1

The tires should say along the edge how much air/pressure to give them.

Answer 2

You don't give the tire sizes which makes answering this question precisely impossible. I'm going to take a guess though which I suspect is probably right on.

If your tire size is P175/70R13 82S but it should be P175/65R14 81S your actually in good shape, from a tire pressure standpoint. At 30 psi for example the 13-inch tire has a load capacity of 963 lbs. The 14-inch tire at the same pressure has a capacity of 952 lbs - not enough to make any real difference. This is true throughout the range of different pressures. Basically you can run the same pressure in either size with no problems.

If you would like more information the following link contains a tire load and inflation pressure table.

http://www.tiresafety.com/images/Tire%20Replacement%20Manual.pdf

You can look up your specific sizes and compare them at different pressures. Skip to page 28 for the 13-inch sizes and scroll down as needed to get to the 14-inch sizes.

The air in the tire is what supports the weight of the car. Basically a tire then is a container for air. What you want to do when comparing different tire sizes is to match the load carrying capacity to that of the original tire size at the factory recommended pressure.

Hope that helps.

ASE Certified Automotive Service Advisor with 5 years experience in the tire (tyre) industry.

Answer 3

Hi you should run at the same pressure as before in order to put 13 inch wheels on instead of 14 inch your friend has probably gone up in profile if not your gearing will be out car should go a lot faster fromm standing start really need to know what tyres you have taken off and replaced with

Answer 4

Here in Australia, we run out tyres at 32lbs for highway use. Always check tyres when they are cool because after driving for a while tyres show a bit higher pressure. I for one would go back and use the original rims.(when money permits of course ) 13 inch rims/tyres would give you poorer economy and would give you a false speed reading on your speedometer. The engine has to run at a higher rev rate for the same speed as your 14 inch rims.

Answer 5

For general use try 28 psi, increasing to 30 if you are carrying four passengers or travelling on the motorway.

I would try and change the wheels back to 14 inches as soon as you can, try bay, steel wheels should not be expensive

Answer 6

If you look on the side wall of your tyre the pressure required should be printed on there. But any garage that has an air link should have a poster stating the correct tyre pressure required for your tyres. It doesnt really matter what make of car your tyres are from as long as he hasnt mixed sizes or makes ie radials and crossplys.

Answer 7

run 30 in the front and 26 in the rear, should be fine at that.