I just bought my 1st Jeep. It's a 2011 Unlimited Sport. I love it in almost all aspects. All but one. It does great on rough trails. It looks great and it's not a bad ride either. BUT, overdrive absolutely sucks unless i'm on a level road or going downhill. whether i'm going 45 or 75. If it goes into overdrive, it won't be there long. If i go up ANY angle of an incline, it slows down constantly. and then has to downshift. I have a friend with a 2007 and he doesn't have that problem at all. His is just as stock as mine. Just has a lift with tires. So i bought the Superchips Traildash. I've heard all kinds of good things about it. I can't tell a difference in power whatsoever. The only difference that i know of between my Jeep and my friend's Jeep is he has the towing package which i'm being told has the 4:10 ratio where mine has 3:73 ratio gears. does that really make that much of a difference???

 

Not sure which Jeep, yours or your buddies, had the tires & lift. But in any case, larger diameter tires will lower the RPM's just like changing to a numerically lower gear ratio -- One can use a Procal or equivalent to reset the tire diameter in the PCM so the shift points and speedometer are at least accurate. 4.10 gears don't sound that different than 3.73, but it's a full 10% difference. Larger tires + 3.73 gears will seem much different than 4.10 with stock tires.

Regarding not feeling any more power with a tuner (superchips), welcome to the club. Marketing is always better than reality.

 

3.8 + 3.73's + tires too big + incline = fail. Since you have the tuner make sure you reset the shift points for the new tire size.

 

Congrats on the Jeep and welcome.

Yes, gearing makes all the difference.