I had a blowout yesterday. I decided to be somewhat frugal and investigate which new tire to buy. I checked Consumer Reports, and they have some ratings to work from. They also say, “You’ll usually find the proper size on the doorjamb or inside the glovebox or fuel-filler door. Be sure new tires are the same size with the same speed and load ratings.”
My certificate says p205/65tr15. My remaining tires (original from dealer) say p205/65r15 92H. There is no load/speed rating on my car’s certificate or in the user’s manual.
Questions:
Does the new tire have to match the speed and load rating of the other three, or just be at least the minimum for the car?
What is that “t” in the “65tr15” on the certificate about?
How do I find out what the minimum speed and load ratings are for my car? I’m going to try calling the dealer, but who knows if I’ll get someone competent.
Well, I’m no expert, but I’m pretty sure the speed rating of the new tire doesn’t have to match the other three. However, it will be the “weakest link.” So if your new one is rated lower, say, S, you can’t take the car past 112mph (which is the maximum speed you can take an S-rated tire to (and then I think only for ten minutes, technically)). H is rated to 130mph.
The load rating tells the weight capacity per tire. So I guess in this case you’re interested whether the total rating of the four tires is enough to support the car plus cargo/passengers. Here it might make sense to stick with the 92. It’s not like you’d save a lot of money going with something slightly lower, anyway.
Of course, many people will tell you that matching wear on the tires is important, i.e., you really ought to replace tires in pairs. In your case you can keep one of the three remaining as a spare and buy a new pair that matches across the board.
Never heard of the “tr” code. Usually, it’s just “r” for radial.
Either way, it’s the same size tire specified on your door jamb as what’s actually on the car.
If this is just a “grocery-getter” and commute car, don’t sweat the load and speed ratings. Even the cheap ones carry an S rating as well as a load rating of 92.
If the blowout was on the front, you might want to get two new tires, or at least have one of the existing tires swapped from the rear. Different tires on the front wheels might lead to unpredictable changes in handling due to differences in tread type and wear.