Tire sizes not making sense

[AdamG]

I am currently tire shopping...

the door sticker says to use 235 75 16

I bought the truck used and it has 245 75 16 that are now bald.

While shopping at Walmart, Costco and a few other web sites, it says that the truck can use 255 70 16 and well as what the sticker said.

 

This doesnt make sense.

wouldnt the 255 70 16 tires throw off the speedometer?

[lowrider]

235/75/16 should have the same OD as 255/70/16. So, no, your speedometer should not be off.

 

Lou

[dizzy]

while it can vary by MFG, the 245's are 30" diameter same as the 255's but the 255's are a .25 wider as mentioned.

 

Too bad you were not out in Central Valley CA, I'd make you a heck of a deal on a used set of 4 Bridgestone OEM 245's I removed them with only 5,000 miles on them. I only removed them to install the BFG's, I couldn't see giving those take offs to Xyz's Tire, have them charge me to dispose of them, knowing full well they would turn around and resale them. I figured I could sell them at a swap meet for $150.

[mooreapi]

AdamG,

I am currently running 255-75R16s on my Silverado. My speedo has been 2-3MPH off (reading 70MPH when GPS/police radar say 73 ) since, I think originally they were 245-70R16s.

Also remember that OEM speedos are made with some error built in.

 

Matt

[redvett]

Also remember that OEM speedos are made with some error built in.

 

The MFR's try to keep the speedo correct as possible but the stackup between the tires,calibrations & speedo head will sometimes cause a few MPH difference. Remember that the goverment allowed varance is +- 7 MPH.