Mountain driving w/auto Opinions?

[Ramblin Fever]

Ok, I've been living back in Colorado for 4 yrs. The truck in signature below has been in/out of the mountains, over Loveland Pass/Eisenhower tunnel more times then I can count.

For those that are unfamiliar with Eisenhower/I-70 corridor, it's a stretch that climbs to 11K+ at the Continental Divide.

I've always had the impression that for hilly/mountainous terrain, without towing, one should leave the auto in D with the "Power" mode ON to allow the engine/transmission to decide what gear is best.

The truck is always put in "Power" mode a good 2 miles before entering the mountains, and stays in "Power" mode our whole mountainous drive.

Toughest part for the truck, as you can imagine, is the climb in towards the tunnel. The truck flies up the first 3 miles at 65mph & 3K Rpm's or so, the last 1 1/2 miles before the tunnel it typically drops to 50 MPH, 3500 - 4K RPM's.

Rarely will I allow it to go over 4K, if it tries to, I let off the gas a bit. Basically, I don't like to push the truck, and I never use Cruise.

I've never encountered any kind of issues, I'm just personally double checking my own driving characteristics.

Am I revving truck too much? And have I been using the right mechanizms, i.e. gear selection "D" and "Power" mode?

FWIW - whenever I have a heavy load, more then 450# inside truck, and/or pulling the boat, I then keep the truck in the "3rd" gear, and "power" mode.

If I'm understanding "Power" mode correctly, it's kind of like turning OFF O/D on other Auto's? Basically saying that it will gear down when it needs to, often times before ONE thinks it needs to?

If it's any big importance, I run tires that are 1.5" bigger then stock, with a good 300# pushbar on the front as well.

[amigo-2k]

Sounds like you are doing all the right things.
This is what I can recall from a disscussion some guys were having about driving from the East coast to Moab:

One of the main reasons for the higher RPM towards the end of your uphill climb is due to the higher elevation. If you could pull over, wait a minute or two and then start again the ECU will recalibrate itself due to the thinner air

[Ramblin Fever]

Didn't know that, that's interesting.

By pulling over, would that also mean to shut off the truck, or just let it idle?

Do you personally think that the RPM range of 4-4500 for a very short matter of time is harmful? I believe the truck gears itself down to 2nd when it does this, but I won't let it hold there for long before I back off the gas pedal.

Thanks for your reply.

[amigo-2k]

yup, shut'er down.

The last time I was in the mountains was in a 99 Trooper, and we shifted it down into 3rd to make it up the moutains. The same guy took his trooper again (to Moab) pulling a popup camper and it was the same deal (drop it to 3rd and climb).

I use to drive around the city in 3rd for a couple of years, to help stop the gear hunting around town.

[Cat Fuzz]

The power mode changes the shift points of the transmission. Overdrive still works, but the tranny will shift later while accelerating and will downshift sooner when you are passing or climbing hills.

[rodeo02]

Let the tranny do it's thing in drive/4th/OD *automatically* unless it is doing a lot of hunting in/out of OD, or the torque converter keeps locking/unlocking. The 4L30E will hold itself in a lower gear after a few minutes of stop & go driving as predetermined by the PCM.
G/luck
Joel

[Ramblin Fever]

Great, thank you all for your replies!