That is why I am going to make my trip next week, towing my 5,000 pound travel trailer 1,000 miles round-trip, with the stock tune. There is no sense in using 91 octane if I am not getting any more power over stock.

I brought my trailer home yesterday from storage. I live in the mountains and I have to go up a 6% grade for 8 miles. I usually have the Tow Tune programmed and 91 octane in the tank. Yesterday, I had 89 octane and stock tune. I crested the top of the last hill in second gear, manually held in second gear the whole way up the hill, and the accelerator pedal to the floor. This is exactly the same scenario as when I am on the flashpaq Tow Tune. I topped out at the same speed as I do on the Tow Tune. The only difference I noticed is that the truck maintained second gear all the way to the end. With the Tow Tune, on the last 500 yards to the crest of the hill, the transmission will many times downshift into first gear, wanting to build up r.p.m.s and speed I suppose.

The fellow, on the flashpaq forum, that works for Superchips stated that they recommend 91 octane with the Tow Tune to reduce any chances for pre-detonation since their programming reduces the torque management a little bit.

 

I use the 93 octane Predator tune for daily driving and towing. Does the job well for both and when not towing gets enough better mileage to save about $1.26 a tank full paying $.20 more a gallon for the 93 octane. This is with the MDS turned off.

 

Wow, I wouldn't have expected that. I wonder if the fuel economy would be better (enough to make break even) buying 93 over 89 on a stock truck? There are a few placed around here that you can still buy ethanol free gas. That might help as well.

 

I've always gotten enough of a gain on the performance tune with my Superchips to more than make up for the cost difference in the gas. I found that the most economical as far as cost per mile driven is the Perf Tune with 93 octane gas. I actually come out WAY behind running the economy tune with 87 octane gas...

 

I just returned from my trip, 1,000 miles round-trip, pulling a 5,000 pound travel trailer. I have always used the Superchips flashpaq Tow Tune in the past but on this trip I was stock.

My observation:

I got the same fuel mileage. Around 8.0 to 8.3 m.p.g. (according to the overhead computer).
I saved money. Purchasing the factory 89 octane versus the Superchips recommendation for 91 octane with the Tow Tune.
The best part...I had better control of the transmission gearing. I was able to modulate the accelerator pedal to maintain 3rd gear (2005 without Electronic Range Select) for longer periods before the transmission kicked down to 2nd gear. Even after a downshift to 2nd I was able to get it back up to 3rd again and hold it for a while.

With the Superchips flashpaq I was not able to hold 3rd gear for very long. The slightest application of the accelerator would always force a 2nd gear downshift. I would end up pulling the whole grade, from the bottom, in 2nd gear. Manually shifted into second to prevent back and forth shifting between 2nd and 3rd. Without the flashpaq Tow Tune I was able to get 1/4 to halfway up a grade in 3rd before the transmission would downshift into 2nd.

From now on I will only use my flashpaq (#3815) for the 91 Performance and 87 Octane tunes. I really like how it performs. The MileageXS tune hurts my mileage and the Tow Tune is too aggressive with wanting to downshift the transmission and requires 91 octane.

 

I just got my sc and I love it