my dad says his truck gets better fuel mileage on the performance setting than the economy. is this common? his truck is a 99 with the auto, muffler deleted and k&n stock replacement.

 

If you can drive it really easy and really nice that can be true. For most of us that is not the case though.

 

I get way better mileage in the performance setting. I really don't see a difference in milage between off and timing settings.

 

You are putting the toggle switch in the middle for timing only correct? If not you are turning the box off!!!

 

correct, thank you

 

Correct, Ihave way better mileage in the perf mode.

 

I do too. I'm talking WAAAYYY better. Gonna have to run a few tanks to check this out but if my figures are even close..this is great!
Mike

 

It's dependent on which program you have loaded. For me, the Aggressive tune does not yield better economy. But it does provide a lot more fun!

 

Mine seems to get better mpg on performance setting as well. I attribute this to not using as much throttle to get the same mph up the hills as when on timing only or off. The hills I have to go up to get home from work are 6%, one of which is 12 miles. Maybe I'm just blowing smoke out my butt, who knows?

 

I'm running the HRVP-44 tune and in L3 (timming & fueling) I'm seeing 14.8 to 16.6 mpg. On L2 (timming only) I'm seeing 17 mpg and better. Of course 99% of the time I'm on L3, so i don't have a lot of data on L2. These are all un-loaded, driving on I-15 up and down several grades per day.

I just up-loaded the newest version of the Aggressive Tune, so I'll be checking the mileage on that.

 

Finally got to check this out with pen & paper. Mileage was very good in the performance mode (23.4mpg) but not as good as my scanner was telling me.
I've re-filled the tank and will run in the mileage mode for awhile. I'll post something when the results are in.
Mike

 

It will probably go down. I too get WAAYY better mileage with the original STOCK AGGRESIVE tune.

 

wow then somethings really wrong with my truck, im getting like 13mpg no matter what. im gona have to get my vp44 checked out next week. unfortunetly thats after my big trip to the dunes.

 

You might want to check/clean or replace your IAT. It can throw your mileage off if it's not working right. While your at it check the MAP sensor. It's in the same area as the IAT. Sometimes just cleaning them both off(electrical contact or break cleaner) will improve performance.
Mike

 

new IAT, and checked map. did that maybe 1000 miles ago