Right now I am running 225/70-15's, on my Ford pickup. I'd like to upgrade to stock 16" wheels and tires. Anyone know what sized tires I can use, without throwing my speedometer/odometer out of whack?

(Yeah, I know it's a Ford, but I picked it up for next to nothing...Not a bad little truck however)

If I had to take a guess, you'd have to get 65R16s or 60R16s. But don't take my word for it. Use http://www.tirerack.com and goto their upgrade garage. Enter in your year and model, and they'll give you the stock size and what tires to get if you decide to upsize your wheels.

A 225/70-15 is 27.4" tall (short for a full-size truck). You need to match that height within a half-inch if not offsetting your speedo is critical to you. According to the numbers, a 15" rim is 381 mm in dia, and the 225/70 has a sidewall of 157.

157 + 157 + 381 = 695 overall height.

A 16" rim is 406 mm in diameter- the rest of the tire size ("235/65" for example) can be used to figure out the overall height on different combinations (ie: 235 x .65 = 152. 152 + 152 + 406 = 710... an exact match in the world of tires).

www.1010tires.com has a tire size calculator.

Going to a 16" rim, you would likely need to go to a 65-series profile tire. Watch your load rating if you're hauling/towing.

If I had to take a guess, you'd have to get 65R16s or 60R16s. But don't take my word for it. Use http://www.tirerack.com and goto their upgrade garage. Enter in your year and model, and they'll give you the stock size and what tires to get if you decide to upsize your wheels.

221177[/snapback]

Thanks Z28, for the tirerack site was/is very helpful!

A 225/70-15 is 27.4" tall (short for a full-size truck). You need to match that height within a half-inch if not offsetting your speedo is critical to you. According to the numbers, a 15" rim is 381 mm in dia, and the 225/70 has a sidewall of 157.

157 + 157 + 381 = 695 overall height.

A 16" rim is 406 mm in diameter- the rest of the tire size ("235/65" for example) can be used to figure out the overall height on different combinations (ie: 235 x .65 = 152. 152 + 152 + 406 = 710... an exact match in the world of tires).

Thanks balthazar, for the detailed reply, which helped me better understand the dynamics between wheel/tire dimension/ratio's.

Is there a big difference between a 15 X 6 wheel, versus a 15 X 7 wheel? Can I use the same tire on both wheels?

An early '90s Goodyear tire phamplet I have on hand says a 235/60-15 is approved for useage with a rim between 6" and 9"... so there's a comfortable range there. Keep within the recommended range and you'll be fine; you wouldn't want a 195 on an 8" rim. I ran 225/70s on a 6" rim for years, a 235 on a 7" is fine. The tire manufacturer will have the specs.