The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tires width. The bigger the aspect ratio, the bigger the tires sidewall will be.

What do letters on tires mean?

The number is the load rating, or the amount of weight that it can handle. The letter is the speed rating, or the maximum speed the tire is built for. As an example, a tire rated 90R could safely carry 1,323 pounds and travel at 106 mph.

What do the letters and numbers mean on a tire?

The last grouping of characters, tied to the tire type, size and construction, represents the load index and speed rating. Also known as the service description, the number indicates the maximum load the tire can support when inflated properly, and the letter represents the maximum speed capability of the tire.

How do you read a tire for dummies?

0:121:58How to Read a Tire Size & Understanding a Tire SidewallYouTubeStart of suggested clipEnd of suggested clipThe 109 is the load index which represents a tires maximum load carrying capacity at maximumMoreThe 109 is the load index which represents a tires maximum load carrying capacity at maximum inflation pressure V represents the speed rating which is the maximum speed capability of the tire.

What does R mean on tires?

radial construction P identifies your tire as a Passenger Tire. For example, this aspect ratio of 50 means that the tires section height is 50% of the tires section width. R indicates the construction used within the tires casing. R stands for radial construction.

What does the letter D mean on tires?

diagonal bias ply construction The D indicates that the tire is a diagonal bias ply construction and the R indicates that the tire is a radial tire construction.

Can I use 225 tires instead of 215?

Yes, you can. But only if the rims on your car can accommodate tires that are 10-20 millimeters wider. Bear in mind that wider wheels require more fuel due to their increased rolling resistance. Again, wider tires are more costly than narrower ones because they need more rubber during construction.

Whats the difference between D and R on tires?

The difference between the two trailer tire sizes is that the letter D in the first size you listed ST205/75D15 stands for bias ply and the letter R in the tire size that they put on your vehicle stands for radial. A radial tire will normally run cooler than a bias ply tire, especially when the tire is under a load.

What does the R and D mean on a tire?

R is for Radial, D is for the ply rating (8 ply), generally for trailer tires.

Whats the difference between 215 and 225 on tires?

The 215 tires will provide less grip than the 225 tires due to their different widths. With an increased grip on the road surface, the 225 tires will achieve greater levels of shorter braking distances while increasing traction, especially on wet surfaces.

Can I use 215 50r17 instead of 225 50r17?

To be honest, the difference between the two are so slim youre not going to notice any real advantages / differences. Your speedometer is going to be slightly off and youre going to be paying more for the 225/15s (larger tire, more rubber = increased price). The choice is up to you.

Should I get H or V rated tires?

To support running at higher speeds, V-rated tires will have a stiffer sidewall and slightly firmer ride than H-rated tires. For normal driving conditions the H-rated tire will provide a more comfortable ride and the V-rated should give slightly better handling.

What does the R or D mean in a tire size?

Question: The difference between the two trailer tire sizes is that the letter D in the first size you listed ST205/75D15 stands for bias ply and the letter R in the tire size that they put on your vehicle stands for radial.

Can you mix D and R tires?

Expert Reply: Its fine to use a radial-type tire as a spare (a tire with r in its size code) with a trailer that has Bias ply d tires but for a short distance in the event of a flat tire. But mixing tires is not recommended for everyday use because their internal construction is different.