CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Tire Size on 2001 Infiniti QX4

I just bought a used (obviously!) 2001 Infiniti QX4. Before going thru with the purchase I took the vehicle to the local Infiniti dealer for a free inspection. They said that the vehicle has the wrong size tires and that I really need to replace them. The dealer I bought the car from is an old friend of the family so I’d like to think I can trust him. When I told him what the dealer said about the tires, he said that the tires on the vehicle are fine but that if I really wanted to replace them he’d get the tires for me wholesale.



I went on TireRack.com and sure enough, I can’t find the tire size I have on the vehicle listed as an acceptable size for my vehicle. Can anyone help me determine if it really is essential to replace the tires? The ones on the vehicle are P225/60R17. The dealer recommends P245/65R17.



Your help is much appreciated!!!

Check your door jam or your owner’s manual and see what’s recommened for your car. If the dealer is right, the ones on the vehicle are 20mm narrower and significantly smaller in diameter than those recommended for your vehicle. The difference, IMHO is significant enough to affect handling and braking capabilities. I’d recommend replacing them.

But shop around. You may be able to do much better than the dealer’s wholesale price.

I just googled tire 2001 Infiniti QX4 and from one web page got the following info…

The QX4 is available in 2-wheel drive with standard 16-inch aluminum alloy wheels and P245/70R16 tires, or with Infiniti’s advanced All-Mode 4WD system.

If you have a GPS system that tells you the speed you are going, I’d compare the GPS reading to the speedometer reading. See if the speedo is giving you a reading close to accurate.

The tires on the car are a slightly lower profile tire and slightly less wide than the specified tire. The difference seems small. If the tires are in so-so shape perhaps taking up the offer for wholesale pricing on a new set is a good move.

If the tires are in good shape and the speedo reading is reasonably close to accurate I’d run them out. The next time you need tires replace them with the proper size. My guess is the previous owner needed tires and the shop didn’t have the correct size in stock and made this substitution rather than taking the time to order in the proper sized tires.

I’m convinced. The man needs new tires.

Your family friend probably can still be considered trustworthy. If they don’t have the correct size in stock tire dealers will sometimes throw on whatever size they have in stock that will fit the rim. It’s wrong, it’s dishonest, and it can be unsafe, but some do it anyway. Your friend probably never even knew.

Your tires are about 2 inches smaller in diameter than stock, about 6% off on circumference. It’s enough to make a difference in ground clearance of one inch, if that’s a factor, and your speedo will be off about 6%. I’d prefer stock size.

I’m sorry to burst your bubble, but your friend maybe trustworth, but he isn’t knowledgeable.

A 225/60R17 is 3 sizes too small for your vehicle. They have much lower load carrying capacity and that increases the risk of a load related tire failure - and those sometimes have tragic results.

Those tires need to be replaced with something that has the same or more load carrying capacity as the originals.

If the load index on the current tires is insufficient for the weight of the car, which may be the case here, then your friend is negligent in telling you that they’re fine.

My guess is that the tire dealer probably told the family friend that they’re fine. If the friend knows nothing about cars and relys on the tire dealer’s expertise, then the family friend isn’t negligent…the tire dealer is a rotten scoundral.

Don’t know if you solved your problem lullmann but I owned a 2001 Infiniti QX4 and I’m in the market for new tires now and I have the manual and I’ve checked the front driver’s door panel. Here’s what you need: P245/65R17 105S

I sure wouldn’t have anything else. Good luck!