2nd Gen Non-Engine/Transmission Tires size vs distance traveled...

[Gary - K7GLD]

OK, this subject has been discussed before - my truck door sticker specs 245 x 7. 5 size tires, but it came equipped with 265 x 7. 5 - and some here claim proper speedo and odometer adjustments have been made for the different (larger) diameter tires...



BUT, when I made my trip from my place to my folks up in Payette Idaho - a trip that USUALLY registers 650-660 miles on OTHER vehicles, I find that same distance has SHRUNK down to just under 600 miles on my NEW truck...



Strangely, when I calculate the DIFFERENCE in circumference of the tires specified on the truck's door sticker against what it ACTUALLY has - guess what? I find that if I allow for the difference, I would have actually traveled a hair less than 650 miles just like always...



Someone wanna tell me AGAIN the our speedometers have been calibrated for the upgraded tire sizes...



Guess what that does to yer fuel consumption calculations - regardless of whether ya use the vehicle computer readout, or figure it manually!



8. 2% makes a pretty BIG difference!

 

[WadePatton]

Gary, I never told you squat about YOUR odometer. I might have stated that MY odometer is perfect with 265 tires. But mine was OEM'd AND stickered for 265 tires. It took you a 650 mile ride to figure that out? I've run off-sized tires and different FD ratios often enough that it's just a habit to check my odometer against mile markers any time I'm on a road marked with them. Which ain't often.



If it was spec'd with 245's and came with 265's then the dealer owes you for an odometer calibration.

 

[Diesel Freak]

enter your tire size and final drive ratio in the appropriate box.



Tire calculator

 

[Gary - K7GLD]

Wade sez:



"Gary, I never told you squat about YOUR odometer. "



UMMmmm - strange, I don't see any names mentioned in my lead post above - fact IS, YOU never even came to mind as I posted above - why would you even assume I WAS referring to you? (the song "you're so vain" comes to mind)...



" I might have stated that MY odometer is perfect with 265 tires. But mine was OEM'd AND stickered for 265 tires. "





UMMmm again, this WASN'T about YOU!





"It took you a 650 mile ride to figure that out?"



Yeah, well, unlike some of the other "sharp fellas" here, I usually wait for a long trip over a pretty well known course and speed to make checks like this, and it IS a new truck - but like I said I'm not as sharp as some...

 

[roadbyte]

Tires

Thanks for the percentage now I can figure out what my MPG will be when I go from the stock tires to the 265.

 

[klenger]

My truck was spec'd with 265 tires, but the door sticker still says 245's. I think that 265's are standard now, even with the basic tires. My odometer is right on.

 

[Shovelhead]

Gary, it looks like you just received 8. 2% more warranty coverage (milage) for free.

 

[jbone]

Gary, I think the 'stealer' can adjust your ratio in the computer for you--of course that means he gets one more shot at screwing things-up!!!! But might make you feel better with correction??

R, J. B.

 

[thepitts]

Try here

This site is easy

http://www.sgmotorsports.com/tiresize.htm#ustires



Shows my diff between 265 and 285 at 3. 73%

 

[WadePatton]

I am part of the collective--that you imply led you astray. I did post on a 245/265 thread before. I thought maybe you read it.



I'll restate the odometer checking method that I've found very quick, easy, and cheap.



Find a road that has mile markers. The farther you travel along this marked route the more accurate the comparison will be, but ten miles is a good run.



Note the trip odometer reading or reset it exactly on the first MM then you watch the MM's. At the tenth one, record your trip odometer reading.



If the trip odometer has indicated ten miles you can worry about other stuff. If the trip odometer has logged something different from ten miles, then do some calculating.



If it reads 8. 4 miles then you're off 1. 6 miles per 10 or . 16 per one mile, or 16 per hundred or 160 per 1000. See why I use 10 miles?



Then, if necessary, I play with ratios and calculaters to make a MPH reference chart for the vehicle in question.



Matter o' fact I think a TN state trooper suggested this method to me once. And he gave me a court date too!

 

[Gary - K7GLD]

All comments appreciated - I primarily posted the lead as an intended "heads up" for others who have differences between door sticker spec and actual tires/wheels... My truck had been upgraded, presumably at the assembly point, with the larger wheels and tires - and while some trucks are possibly adjusted in their computers, looks like mine was not...



Obviously, there are methods that can be used to check actual vs indicated distance traveled, MY truck is new, used mostly between our rural home and town to get the daily mail - the longer trip I just returned from was the first opportunity out on the open road, empty, to check things like odometers and fuel mileage...



And just because SOME of us have access to roadside mileage markers in their daily travels, doesn't mean we ALL do... The rest of us then must use other means as they present themselves...



It ain't rocket science - and I'll be checking with my excellent local DC dealer to see about adjustment.

 

[baby.driver]

For those who don't know

California really sucks as to road mile markers.



Jay