I have a 2002 Trooper very well maintained with low mileage. I recently purchased a 3000lb RV and towed it about 300 miles. Although the tow rating is 5000lbs I found that the trooper struggled with the load. I ran in 3rd gear as it was difficult to maintan crusing speed (60-65) without the trans continually downshifting. At about 60mph in 3rd I am turning about 3000rpm which I know happens to be at peak tourqe rating (215foot lbs). I would prefer not to spin the motor that fast for an extended period of time but now have no other choice. I have 245/75 16 tires and was woundering if I might put 15in wheels and say 225/70 15s on to effectively raise the gear ratio. Does anybody know if that would change much. I want to be able to stay in 4th most of the time. Any other ideas would be appreciated.