Tire Sizes

By admin, 10 August, 2005
Topics

Member for

16 years 2 months

Balandar

18 years 3 months ago

Recommended Cold Tire Inflation for the GTO

Occupant and Cargo
Weight: 470 lbs. (210 kg) or Less

245/45ZR17 95W Front: 30 psi (210 kPa) Rear: 30 psi (210 kPa)
235/40ZR18 91W Front: 33 psi (230 kPa) Rear: 33 psi (230 kPa)
T145/70R17 96M Front: 60 psi (420 kPa) Rear: 60 psi (420 kPa)

Occupant and Cargo
Weight: Up to 740 lbs. (330 kg)

245/45ZR17 95W Front: 35 psi (240 kPa) Rear: 35 psi (240 kPa)
235/40ZR18 91W Front: 33 psi (230 kPa) Rear: 39 psi (270 kPa)
T145/70R17 96M Front: 60 psi (420 kPa) Rear: 60 psi (420 kPa)

Member for

16 years 2 months

Balandar

18 years 3 months ago

Also, If your vehicle has 235/40ZR18 91W size tires, and you drive 100 mph+ you'll need to have a higher psi in your tires. Check your manual for specs.

Straight from the manual (note that this is not the size of the GTO tire!).

P215/70R15 97S
A B / C D E  F

(A) Passenger (P-Metric) Tire: The United States
etric tire sizing system uses the letter “P” to designate
a passenger vehicle tire. The European metric tire
sizing system does not use the letter “P” to designate a
passenger vehicle tire.

(B) Tire Width: The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.

(C) Aspect Ratio: A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is “70,” as shown in item “C” of
the illustration, it would mean that the tire’s sidewall is
70% as high as it is wide.

(D) Construction Code: A letter code is used to
indicate the type of ply construction in the tire. The
letter “R” means radial ply construction; the letter “D”
means diagonal or bias ply construction; and the
letter “B” means belted-bias ply construction.

(E) Rim Diameter: Diameter of the wheel in inches.

(F) Service Description: These characters represent
the load range and the speed rating of a tire. The
load range represents the load carry capacity a tire is
certified to carry. The speed rating is the maximum
speed a tire is certified to carry a load. Speed ratings
range from “A” to “Z”.