I bought my truck used with 20" wheels. Recently found out the computer was not reprogrammed result being inaccurate speed, mileage, etc.


The dealership has offered to reprogram. My Dodge gasser had a new flash downloaded and reduced my mileage by 20-25%!


Can anyone give me an idea what to expect?





Thanks.

Wheels don't matter, tire size does.


What size tires are u running?

I haven't actually measured the tires but they are big. The OEM wheels/tires were 16" and when I put the spare next to the tires installed, the difference is huge!


Hope this helps ....

Tell us what the tire size and make is and we can look it up.

The Tires are Falken Ziex S/TZ01 P275/55R20 116M+S ....

It shows they are 31.89" dia. and stock is 31" so they are wider but not much difference in height.


U shouldn't be off more than a couple of mph at 60.


I wouldn't mess w/ it.


BTW they are passenger tires and I didn't get to see the weight rating but I'll bet there aren't heavy enough to tow your camper.


Nitto tires in same size only have 2750 weight rating.Edited by: Dmax Tim

Stock w/16" wheels have 31" tires? They look much bigger sitting next to each other.





You have me really curious now. I'm going to go home and physically measure them. I'm comparing to the spare tire since I don't have the OEM wheels and tires. Would the spare be any different?

nope, spare is full sized 245 75 16 is what comes stock

Go here and you can compare the tire sizes:


http://www.discounttire.com/dtc/brochure/info/tireMath.jsp


From that site it looks like your new tires are 1.44 inches taller

I don't think you new tire and rim combo is going to support much weight. I would check out the ratings on both before you hook to your 5'er or you'll squash those wheels like a bug, along with your truck.