hmm, should i go get a reprogram? i had the 16's stock rims on the stock wranglers.

i now have 15" rims on 32" tires.

 

It hurts other things too, beginning with your pocketbook, the bigger the tire, the more it costs. And you multiply the added cost by 4.

The bigger the tire is than the stock size, the more it decreases braking efficiency and the result is that it takes more distance to stop. This is a big safety issue. Tires 2 or 3 sizes larger than the stock size weigh a lot more than the stock tires, and your brakes are designed for the stock tires. The extra weight of the oversize tires is more than the brakes can compensate for.

In addition, your mpg goes down and you can't accelerate as fast as with the stock tires.

 

re-gearing will alliviate the acceleration problems and will help somewhat with the braking efforts. it will also bring MPG back up to near stock.

 

how will regearing help with the braking issue?

 

I bet he means via engine braking.. It's still a safety issue though..

 

^---u got it. engine/compression braking helps somewhat. there are ways around the braking problem like turning the OD off when going down steep grades and in a manny tranny downshifting.

even still, stepping up one or two sizes larger and not driving like a maniac, the brakes will still work pretty effective.

 

Yeabut what when that jackass pulls out in front of you and you've got to panic stop! Engine braking won't help much there..

 

well then engine braking would be less effective with a regear since that compensates for the larger tire
having a larger tire spins the tire and the drivetrain less to cover the same distance compared to a stock circumference
when coasting down engine braking would be increased if you left the gears alone and did not allow the engine higher revolutions

or am I missing something here

 

Sounds right Neil...as for your tranny being programmed for stock tire size...its a learning unit. If you drive Highway alot...it learns that shift pattern and shifts sooner, if you drive city a lot it waits and shifts later...it should only take a week or two for it to "relearn" the new tire size and change shift patterns appropriately.

Neil did you notice this when you upsized? Was there a noticeable difference in acceleration, shifting, etc.?

 

there was a noticable difference in off line acceleration and braking power
the shift points seem to be OK though
can't for the life of me see how 4 bangers or even a 3.0 will perform well with 33" tires
even though 207 HP and 238 ft lb of torque are not that much it is more than the smaller mills put out
I noticed a difference as soon as I pulled out with the new skins