Tire Size Question, Tire Experts
TECH Fanatic
Joined: Jul 2006
Posts: 1,179
Likes: 0
From: North Bay, Ontario
Your current tire has a diameter of 26.681 inches and a sidewall of 4.3405 inches
A 245/40/18 will give you a diameter of 25.716 inches and a sidewall of 3.852 inches
Or... for an even lower profile u can go 245/35/18 which gives you a diameter of 24.751 inches and a sidewall of 3.3759 inches.
Keep in mind that when you change diameters from your stock wheel, your speedometer will not be correct, if you go to a smaller size than stock, your speedo will say your going faster than you really are
For an example if you switch to the 245/35/18's, when your speedo says your going 60mph your actually travelling 55.7 mph which isnt that much of a difference, but just keep it in mind
A 245/40/18 will give you a diameter of 25.716 inches and a sidewall of 3.852 inches
Or... for an even lower profile u can go 245/35/18 which gives you a diameter of 24.751 inches and a sidewall of 3.3759 inches.
Keep in mind that when you change diameters from your stock wheel, your speedometer will not be correct, if you go to a smaller size than stock, your speedo will say your going faster than you really are
For an example if you switch to the 245/35/18's, when your speedo says your going 60mph your actually travelling 55.7 mph which isnt that much of a difference, but just keep it in mind
Staging Lane
Joined: Feb 2006
Posts: 66
Likes: 0
From: Scottsdale, AZ
right now the 245/45/18 has a rev per mile of 777-779 depending on brand. to equal the same rev per mile in a smaller size you would need a 225/50/18. the real question is what size rim you have because most 245/45/18 will fit on 7.5"-9" and most 225/50/18 will fit on 6"-8" rim widths. sooo, if you have your 245/45/18 on a 7.5"-8" wide wheel then you can install 225/50/18 on those wheels and retain similar tire circumference.
