Got 285s, recalibrate speedo or not?

[98ramtough]

I got 285/70/17s put on my truck. The computer seems a little off, or I am getting quite a bit worse mileage. Should I bring it to the dealer to get the speedo calibrated? They said the charge is $70. Seems high to me, but the dealers around here are less than good IMO. Does it just change the speedo or does it change the shifting etc at all? Worth the $70?

 

[hearingyourlies]

From an economic standpoint, I wouldn't bother. Think about it, there is a 3. 49% difference. That means if you drove 100 miles (according to the computer), you really drove 103. 49. 1000 miles is 1034. 9 miles. 10000 miles is 10349 miles ... etc ... you get the point. You're actually saving yourself some warranty time, really. So when you calculate your mileage, remember to add in another 3. 5% in miles ... over 500 miles, it don't seem like much ... until you stop and think that it's really 517. 5 miles. My two cents.

 

[231jasonS]

When i had mine, 285's i could not detect a difference.

 

[rbattelle]

I would. But I'm kind of obsessive.

Problem is, I don't want to go near the dealer. So I'm not sure how I would do it. Maybe see if there's a generous person nearby with a Smarty who'd do it for $20?

Ryan

 

[BGott]

My speedometer is two MPH fast anyway, when I go to 285s it will be closer to correct than it is now.