Imperial Home Page -> Repair -> Wheels & Tires -> Purchasing
For a really excellent overview of tire types and sizes and classifications (for all types of vehicles), make sure you check out the Bridgestone/Firestone website. They have a comprehensive index of what to look for and how to best chose your new tires.
Another excellent website is the Tire Rack website. They are also a great source for purchasing tires...they allow you to "order" through them and also support a local tire dealer in the process. Very good resource!!
There are a number of things you should consider when purchasing a new set of tires:
1) First determine how many tires you need:
JUST ONE TIRE?
If your tires have a lot of remaining tread depth, but you need to replace just one that has been damaged by an accident, road hazard or a vandal, you should replace it with a tire that exactly matches the others. Select a replacement tire of the same brand, line, size and speed rating. While there may be a less expensive tire available, it wouldn't be a bargain this time because it would be different than the other three tires on your vehicle.
A PAIR OF TIRES?
If two of your tires have a lot of remaining tread depth, but you need to replace the other two because they were damaged or have worn out, you should replace them with a pair of tires that come as close as possible to matching your existing tires. While identical new tires are desirable, others of the same size and type can also provide good results. Only consider selecting new tires that are from the same tire category as your existing tires. New tires should be installed on the rear axle.
While your vehicle is being serviced ask your mechanic why one pair of tires have worn faster than the others. Was it caused by a lack of tire rotation, out-of-spec wheel alignment or loose mechanical parts? Once the problem has been found, it can be corrected before it damages your new tires. Keep in mind that your ultimate goal is that all of your tires always wear out at the same time so they can be replaced as a set.
A SET OF TIRES?
If all of your tires are wearing out together, you have the greatest flexibility in tire selection. If you were happy with the original tires, simply replace them. If you want longer tread wear, a smoother ride or more handling, there are probably tires that will help you accomplish that. Review the tire category types until you find a category description that describes a tire that fits your needs.
2) What is the right size for your Imperial?
3) Do I need summer tires, winter tires, all-season tires…?
4) What will be your typical driving conditions...should I chose bias ply or radials for my Imperial?
5) When should I change my tires?
As a tire wears it is important to realize that while its dry traction and handling will improve…its ability to perform in rain and snow will diminish. At 2/32" of remaining tread depth, resistance to hydroplaning in the rain at highway speeds has been significantly reduced and traction in heavy snow has been virtually eliminated.
If rain and wet roads are a concern, you should consider replacing your tires when they reach approximately 4/32" of remaining tread depth. Since water can't be compressed, you need enough tread depth to allow it to escape through the tire's grooves. If the water can't escape fast enough your vehicle's tires will be forced to hydroplane (actually float) on top of the water, loosing traction.
If snow covered roads are a concern, you should consider replacing your tires when they reach approximately 6/32" of remaining tread depth to maintain good mobility. The reason that you need more tread depth in snow is because your tires need to compress the snow in their grooves and release it as they roll. If there isn't enough tread depth, the "bites" of snow your tires can take on each revolution will be so small that your traction will be reduced. Because tread depth is an important element for snow traction, winter tires start with deeper tread depths than standard all-season or summer tires. Some winter tires even have a series of wear bars molded in their tread pattern indicating approximately 6/32" remaining tread depth.
This page last updated October 3, 2003. Send us your feedback, and come join the Imperial Mailing List - Online Car Club