I know there was a thread a while back that had a link to a website that you could enter your tire size and it would tell you the rev/mile that the dealer needs to know to reprogram the computer. Anyone know what thread that was?

As soon as I find out the rev/mile for my pro comps I think I'm going to the dealer to see if they will reprogram my truck. What is a fair price for this service? Thanks.

 

305x.65=198.5
198.5x2=397
397/25.4=15.63
15.63+17=32.61
32.61xpi(3.14)=102.396

5280x12=63360

63360/102.396=618.774 revs/mile

I think my math is right?

I wouldn't pay more than $25 for it.. and that is if they aren't allready doing any other service.

 

Or, you could go to the manufacturers website and they usually have that info posted for each of their tires. Each brand is a little different, so the math doesn't always work.

It's like shoes.....a 12 ain't always a 12.

 

my dealer showed me the programmer. the programmer has all the tire brands, models, and sizes and it programs to that.

 

hmm.. I guess my method is not needed .

 

Thanks for the input. I haven't had much to do with the dealer, so Idon't really know what to expect. I just heard that they would say they couldn't program for anything bigger than 285/70/17 unless you know how may revs/mile.

$25 sounds good. Hopefullythe dealerwill do it for that. We have two here in town so I do have options. I'm probably going to go tomorrow after work.

The reason I am doing this is because I have driven by 4 different road side radar guns and they are consistently 5 mph faster than my speedo at 60 mph. That would make a significant difference is shift points for the tranny, I think.

 

it would make a difference in the cost of the speeding ticket also!!!!!![sm=gears.gif]

 

Good point.

BTW I found out that 618 rev/mile is about right.

 

It is also illegal, doing what you are doing. I guess technically by changing tire size you are tampering with the odometer. You are putting more miles on the truck than what is registering on the odometer .

 

I called both dealers today and one wanted $85 and the other $45 to reprogram the speedo. They both told me that they didn't think they could program for my tire size. They said they only had 3 options. I'm not really sure what to do. They said they couldn't tell me for sure unless they hook it up to the computer and they would charge me no matter what. What do you think?