Found a good deal on some Goodyear Wrangler Fortitude HT tires. They are 255's not 245's which were stock size on my Envoy. So they are 10mm wider and 6.5 mm taller. It's not very much but will it throw off my TCM or ECM enough to be a problem?
Going from 245/65/17 to 255/65/17 Any problems? Stock Envoy
- Thread starter c good
- Start date
If you're replacing all 4 then no... just your speedo will be off by a small amount - about a mph at 65.
HOWEVER, the overall height of the tire will make it a little close for the upper ball joint. I think the max height is 30.5" and 255/65/17 puts you at 30.1"
You can check the speedo differences yourself here: https://tiresize.com/speedometer-calibration/
Overall height differences: https://tiresize.com/metric-tire-conversion/
HOWEVER, the overall height of the tire will make it a little close for the upper ball joint. I think the max height is 30.5" and 255/65/17 puts you at 30.1"
You can check the speedo differences yourself here: https://tiresize.com/speedometer-calibration/
Overall height differences: https://tiresize.com/metric-tire-conversion/
Matt
Member
- Dec 2, 2011
- 4,022
Very Nice! Did it affect your gas mileage from stock? Speedometer still close to actual MPH?
MPG the same avg 15.5, mainly city driving. On the high way speedo says 70 - GPS 72 much better MPG of course. 4.2i/3.73 w/lockers.
When I bought my Envoy it came with 255/55/18s
A bit smaller than stock at 29.04 vs 29.6 of the factory 245/60/18. The speedo is a bit faster than your actual speed.
16.1 mpg mostly city with the 5.3
A bit smaller than stock at 29.04 vs 29.6 of the factory 245/60/18. The speedo is a bit faster than your actual speed.
16.1 mpg mostly city with the 5.3