Put my Predator on 120 for the last couple days because a couple people stated they were getting the best mileage with it on the highest setting on the highway. Can't say for sure yet, but the drivability on the brief city driving I have been doing is quite bad. Takes some getting used to. If you don't keep even acceleration through shifts it will jerk pretty bad. Looks like I am getting good mileage though. I drive on the highway everyday to work. Definitly going back to the 65 tune after unless on long hwy trips. The way it shifts on 120 scares me. I get the feeling like when you are a kid and you are doing something you aren't supposed to. I know my tranny is doing :flipa: to me. It is pretty ****ing awsome how much smoke it throws off the line! I had to do it once...and then one more time to show my friend.

The sifting will smooth out a little. 3-4 will be very firm 75% of the time.
You get use to the touchy peddle in time. (be happy that you missed out on the 1800 rmp surge they had for a while....)
Hope your saving for a tranny upgrade....

I would be worried about tranny slippage with the 120 tune. Without modding it at all i would say thats running a risk. The hard shifting however is most likely resulting from the tansmission having not "learned" the shifting yet. With these new allisons they are "smart" and learn to shift with the new horsepower arround 30 shifts per gear. Best bet is to run about 200 miles or half a tank on the new setting to "adjust" the shifting.

-- Rick

It's going back to 65 tune this weekend. Had to try it once though. Gas mileage seems to be about the same as it is on the 65 tune. No excuses to keep it on 120 anymore seeing as my tranny does not have a death wish.

22 mpg was my best and 20 mpg was my worst on the 120 setting going to Estes Park Colorado from Iowa. On the way back I ran the 65 setting to see if there was a diference. Best was 19 mpg and worst was 18.5. Both bests was in the flats in Nebraska. Only thing I hated about the 120 setting was the cruise control was jerky when it would try to coast and keep 70 mph going down a slight decline. 65 setting was smooth. These were hand calculated and filling the tank to the top of the fill neck to keep it acurate.

It's going back to 65 tune this weekend. Had to try it once though. Gas mileage seems to be about the same as it is on the 65 tune. No excuses to keep it on 120 anymore seeing as my tranny does not have a death wish.

Yea, I tried the 120 tune once....for 5000 miles before it limped the tranny. Then I tried the 85 tune once...for 10,000 miles before I limped it again. :lol:

I'm stopping at 400miles.