Need help on Tire Calibration..
 

Hello Everyone in WA,

I upgraded my 17 inch stock tires and rims (LT 265 70 R17) to 18 inch tires and rims (LT 275 70 R18). I've notice that I have lost 2 miles per gallon when I changed tires. I know if I change to a 275 65 R18 I could get close to my original tires and mileage. The tires are fairly new and I don't want to wait till I change them. Gas is getting high.

I wanted to know if anyone has a Tirepaq calibration unit for a ford F250 that could help me out. I don't want to purchase a unit for a one time calibration. I know I will keep this size tire and rim for my truck. Again I was just hoping if someone could just change infomation on my truck and let me know how much you will charge.

I could meet in the Kirkland, Redmond, Bellevue, Woodinville or Seattle.

Could anyone help me out.

Thanks,

The 70 and 65 are width of tire. Changing those really won't do much. May think about going back to the 265s if you're really worried about 2 miles. If you have 315 or 325s, then a calibration is needed.

Called a few tire shop and they told me that if I change to 275 65 R18 then I could get close to my mileage by 1 mile. Because I have larger tire size I'm losing about 2 miles. I know is not much but when you add it all up 2 miles times 39 gallon = 78 miles lost.

I have access to an AE. We can make the adjustment. Quite simple to do.

I would guess that you aren't really getting worse gas mileage by swapping tires, especially to larger ones. What is happening is you're not registering as many miles as you did previously with shorter tires, so your odometer isn't registering all the miles you're driving. You need a speedometer calibration so it reads correctly. Either way, it's not affecting your actual fuel consumption.

On the plus side, you'll have fewer miles on it showing, at trade in time. lol

I agree with Merc. Grab a gps and go for a drive. Verify your speedo and miles driven.

Very true. The AE will fix the issue. My OD reads 189,000+ I know I've got more miles due to the size of tire. That was before making the adjustment and live tuning. I adjusted to show that I'm going slower than I am.

Sorry I didn't respond sooner. I was searching around and I found out I need to adjust my speedometer for my size tire. I found in my search that a Superchip Tirepaq programmer SC-1846 will recalibrate the speedometer. You metion you have a AE unit that will help recalibrate the speedometer. What is a AE? Where do we have to meet? Please let me know.

Thanks, Mike

AE is an auto enginuity. It does just about everything for our trucks, pulling and reseting codes, speedo adjustments, buzz and cct tests. I can meet you on the eastside if you'd like. Bellevue up through Lynnwood if you'd like.

lostmybeer,

That will be great. What day or evening will work for you? I live in the Kirkland Area, let me know when/where you would like to meet up. Is a quick thing to do?

Mike