Engine/Transmission (1998.5 - 2002) Tire Size & ECM Setting

[Dave Ratcliffe]

I noticed the tag on my door jam says my tires are 245/75R16's but the truck actually had 265/75R16's when it rolled off the lot. Does this sticker mean my ECM is set for the smaller tires, meaning my mileage/speedometer is reading lower than it should?

 

[RADdodge]

I think you will have to ask the dealer that question. If they are a good dealer, they will hook up the scan tool and tell you what your PCM setting is. Otherwise, a GPS or mile markers are your best bet.

 

[BrentL]

Is there a way to reprogram the tire size without going to the dealer? I understand they make a unit for the Ford that will reprogram tire size, HP, and a few other things. Do they have anything like this for the Dodge?

 

[JR2]

There are two units that you can use to run bigger tires. One is the abbot box and the superlift tru speed. There are memeber running each box. If I remember correctly the abbot has to be modified for 4 wheel abs and the tru speed does not. The tru speed has two settings so if you change tires often you can switch between settings. I think the tru speed is cheaper too.



JR2

 

[klenger]

My truck is the same way. I think all the new ones are comming with 265's, but they haven't updated the door sticker. My spedo is fine.

 

[Gary - K7GLD]

Mine's the same way - speedo is off by about 8% - dealer service dept seemed sorta confused as to how to check/correct - so I decided to just live with it for the time being...



Don't want no brain-dead high school dropouts messing up MY truck!



With my luck - they'd blame it on the fancy Genos chrome exhaust extension I installed...