Steve,
Nevermind I found the engine info earlier in the post. Your maximum H.P. is at 1800 rpm but at that rpm your torque is at 1503 lb-ft. Maximum torque of 1650 lb-ft is produced up to 1500 rpm. I am assuming that you are noticing more pulling abilty when you are shifting down into 9th?

 

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Steve,
The data indicates the ideal cruising range for fuel economy and power to be between 1400 and 1600. Your are probrably noticing the increase in horsepower at that 1800 mark but I am concerned that you may burn more fuel than necessary.

 

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that's the reason I'm a proponent of 13-18 speed transmissions-You have a "Tweener" gear so you're not lugging or over revving.

 

I have found while pulling a hill, especially with a heavy load, my turbo will get very very hot if I don't drop a gear and get the rpm up. Keep an eye on the engine temp too. The fan should kick in before it gets too hot, but I sometimes turn on the fan manually if I have a long pull ahead.

 

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Assuming you aren't gelled up, then it will run really crappy for about 15-30 minutes, and then the idle will settle out. Just make sure your wheels are turning when you take off, as they like to freeze when they are parked. A large hammer will solve this problem.

If the truck will be sitting for an extended period of time, then I suggest you have full tanks when you park, and put double the additive in that you normally would, as the tanks will likely do some settling.

 

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