Example tire size: P195/65R15
means it' s a passenger
"195" is the width of the tire from sidewall edge to
sidewall edge.The larger the number, the wider the tire is.
"65" is the tire's ratio of height to width.
Numbers lower than 70 would have a shorter sidewall for
better steering and handling.
simply means it's a radial tire, which has been the
standard construction for
the last 20 years.
"15" is the wheel (rim)
diameter in inches.
That takes care of the tire size, but what are those
numbers and letters after that?
the tire size or somewhere on the tire's sidewall you'll
something like this: 91T
"91" is the tire's load index, which indicates how much
weight the tire can support.
indicates the tire's performance rating.
This is what the manufacturer of the car says the car
should have for optimum performance. The ratings range
from 99mph to 186mph (some people refer to this as the
"speed rating". It is possible that this set of
numbers/letters would not
be on your tire, as it is not required by law.
Tires have a lot of other information on them, like maximum tire
pressure, the traction, treadwear, and temperature rates, U.S. D.O.T ID number,
ply rating, etc.,
but to keep it simple, the above only lists the info
you'll need when you call us for a tire
Information compiled from a
brochure by the
Rubber Manufacturers Association (RMA)
Hervey's Tire Company ~ 22 Union Street Rochester NH 03867 ~
Web Site by Tanya Hervey
Truck Tires are slightly different:
Example tire size: LT245/75R16
"LT" means it's a light truck tire, and the rest of the
info is the same as for passenger car tires
Somewhere on the sidewall there should be a "Load Range"
with a letter. Ex: Load Range E.
The load range indicates the tire's load carrying
capabilities and maximum inflation.