A great deal on the wrong tires is not a great deal. The most common problem we see with tires bought online around Edmonton is a size that is close, but not right. Here is how to check fit before you pay.
Step 1: get your vehicle's spec
Find the tire placard on the driver's door jamb or in your owner's manual. Write down the full size, load index and speed rating, for example 215/55R17 94V.
Step 2: match the rim diameter exactly
The number after the R must match your rims. There is no stretching a 17-inch tire onto an 18-inch rim. If you are buying tires only, this is the first thing to check on every sidewall.
Step 3: match width and aspect ratio
The safest choice is the exact size on your placard. Some vehicles can run alternate sizes, but there are limits:
- The overall diameter of the tire should stay very close to the original, generally within about 3%. A bigger or smaller tire changes your speedometer reading and can affect traction control and ABS.
- A wider tire may rub on suspension parts or the fender liner, especially on full lock or over bumps.
- The tire width has to suit the rim width. Every tire has an approved rim-width range from the manufacturer.
Some vehicles list an approved winter size in the owner's manual, often a narrower tire on a smaller rim. That is a good, safe option if your brakes clear the smaller rim.
Step 4: load index and speed rating
- Load index: equal to or higher than your placard. Never lower. This matters most on SUVs, vans and trucks that carry weight.
- Speed rating: ideally equal to or higher than your placard. Winter tires are often rated lower, and many manufacturers allow that. Check your owner's manual.
Step 5: match the set
- Same size on all four (unless your vehicle uses different front and rear sizes).
- Same model and similar tread depth, especially on all-wheel-drive vehicles. Some AWD systems are sensitive to small differences in tire diameter. Your owner's manual will say.
- Never mix LT (light truck) and P (passenger) tires on the same axle.
Your responsibility as the buyer
When you bring your own tires, you are responsible for confirming they are the correct size and type for your vehicle before work begins. We check the size and condition of every tire before mounting and we will flag anything that does not match your vehicle's placard. But we do not sell you the tires, so we cannot guarantee a part we did not choose. If something does not fit or is not safe, we will stop and talk to you before going any further, and we will confirm any charges with you first.
The easy way to avoid surprises: when you book at our garage in Laurel, South Edmonton, send us a photo of your door-jamb sticker and a photo of one tire's sidewall. We will tell you if anything looks off before you drive over.