2005 Pontiac Grand Prix Wheels

There's a lot more to tires than how they look. The last thing you want to do is buy different tires from different stores or different times. That's like buying one shoe from Walmart today and a different shoe from KMart last week.

Tires have a specific rolling resistance. This isn't as important on the rear, but on the front the two have to be the same brand and model to prevent them from causing a pull or uneven handling and steering response. You will even get mismatched tires if you buy the same brand and model from the same store, but a few weeks apart.

The proper thing to do when you only want two tires is to put the new ones on the front where they will do the best job of preventing hydroplaning, and put the old ones on the back.

If the steel belts were showing, you have to also look at the rest of the tread. If the rest looks okay, there is a broken belt. You'll feel that in the seat and or the steering wheel. If the rest of the tread is worn to the end of its life, you likely have a pretty significant alignment problem. The tire salesman and the installer should be able to "read" the wear patterns. There are three things of significance and you can do two of them. The steering wheel should be centered when driving on a straight road. There can be a misalignment problem yet, but if the steering wheel is off-center, you KNOW there's a problem.

The car should go straight on a straight and level road when you let go of the steering wheel. If it pulls either way, there's normally an alignment problem, but that pull can be caused by mismatched tires too. The third thing is those wear patterns but that takes some miles to start to show up. You also need to look if both tires have the same pattern or if only one has a certain pattern.

Be aware too that some tires tend to develop broken belts, and that resulting horrendous thumping, when they're near the end of their tread life. This applies to Goodyear tires in particular. That happens even when there is no underlying alignment problem.

Wheel bearings normally start to fail by becoming noisy. They'll sound like the buzz of an airplane engine. In addition, if you have anti-lock brakes, GM has a real big problem with their front wheel bearings. The bearings don't actually have a problem. They cause a problem. They develop a little normal play, but that play causes the wheel speed sensors to develop a reduced signal. Those sensors develop a rather wimpy signal to start with, so anything that causes it to get even weaker will cause it to get so weak that the computer can't read it. That can cause false activation, typically when you're approaching a slow speed while slowing down, or it can cause the yellow warning light to turn on while driving, and that will deactivate the system. The aggravating part is a new wheel bearing can cause the same problem in as little as 15,000 miles.

If you do not have anti-lock brakes, and you need to replace the wheel bearing for some other reason, compare the prices for that bearing with and without the built-in wheel speed sensor. It's the same bearing. We found that for some applications, the bearing WITH the sensor cost less than the bearing without the sensor. Buy the less expensive one with the sensor and just don't connect it.

From Csymons712

The check tire pressure light has been on for awhile and I have checked the air in the tires and they are all good. What else could it be?

Mandated tire pressure monitoring systems came along after I left the dealership so I only know what I read and hear from other people. Everything has to work properly so the pressures can be monitored and reported to the computer, THEN you also must have the correct pressures. Just because the pressures are right doesn't mean there can't be some other problem.

The things to consider include driving on a flat tire will destroy the sensor in that wheel, special valve cores are used to prevent corrosion between parts made of different metals, and the computer has to be taught which sensor is where. That can require special tools and / or a scanner. You may also have to do a relearn procedure when a new sensor is installed.

There can also be a receiver for each sensor, and those are in the body but very near to that wheel. Some people, I've heard, would drill three extra holes in the spare wheel so they could mount all the sensors on it, then install aftermarket wheels and tires of their choice on their cars. That doesn't work with all car models if each sensor has to be right by its receiver at that corner of the car.

Sensors can be damaged too by dismounting or mounting a tire onto the wheel without following certain precautions. I've never run into a pressure sensor myself so I can't elaborate more on that.