I have had my new toys for about 2 months now and have some questions reqarding the readings I get on my EGT gauge and Trans Temp. I have an '02 and my new toys include 6.5" lift, 37" tires, DP Tuner, 6637, and 4" turbo back exhaust.

While climb colorado mountain passes (5-7 miles up 8% grade up to 11,500' in elevation) empty, overdrive about 70 mph (1800 rpm with the 37's) the egts climb to about 1200. If I take it out of overdrive and reduce speed to 65 (2400 rpm) they stay around 950 to 1000. While driving on flat terrain at 5000 - 7000 ft at 80 mph the egts are also about 850 - 900 with about 6 - 8 lbs of boost. This is typically the 80 econ setting. When towing a small trailer with 4 dirtbikes, and a bed full of camping gear they would be higher, if I did not let up. Do these seem normal?

My transmission temps average about 80-85 degrees above ambiant air temp when driving on the interstate on even terrain. They climb to as much as 100 degrees over ambiant when climbing the previously described mountains, or driving in town for extended periods. I have experienced 190 degrees on 90 - 100 degree day. Do these seem normal? Do the larger tires impact the trans temps?

Any input would be appreciated.

 

Yep, I easily saw those same temps last summer. The three things that had the most effect on reducing EGT's when climbing up mountain grades was 1) ball bearing turbo 2) 6.0L intercooler and 3) 4.30 gears. With the rpm's up in the proper range and more cool air and less exhaust backpressure, I now cruise up grades with EGT's below 1000 in overdrive. With what you've done now to your truck, those are normal temps.

Again that's normal. Larger tires do create more rotating mass, so there is additional strain on the drivetrain now, and that equals more heat at the transmission.