I just installed a quadzilla xzt on my truck with the stock/mileage/performance 3 way switch and can't tell the difference between stock and mileage whatsoever. I can definately tell the performance position though. I have a couple of questions...is stock in the middle position or is mileage setting in the middle switch position, and has anybody else noticed there is not much difference or is it just me or my chip? Thanks.

 

The middle position is the "timing" postiton. I don't notice any difference, but trucks react differently sometimes.

 

Alright, glad someone else doesn't notice a difference either. I'm going to try it on the timing position and see if i get much better fuel mileage.

 

Yep, the middle position should be timing only. Down will be either off or high idle (if you've down loaded the proper tune) and up will be performance mode.

 

ditto. stock and performance are complete opposite positions - timing is in the middle.

i don't notice much difference in timing either, but there is a mild difference.

also, i haven't really noticed much if any mpg gain in the timing mode.

others in different threads have also stated little to no change in economy.

 

On straight highway I noticed a good difference in fuel mileage (was getting 24 with #1 Diesel with my 99 Cab and Chassis, 4X4 and added weight on the frame for winter driving) In town I didnt notice much of a MPG change, however I could tell that there was a change in timing. Engine ran a bit smoother throughout acceleration. And when I had a stock tranny/engine you could get pretty bad timing surge in the cold weather.

 

Yep Middle is "economy mode" I notice not as quick to accelerate and drops the temp by about 50 to 75 degrees. I have only gained about 9 tenths of a mile per gal "Hand Calculated" but that is better than nothing.
Best way to see the difference is to be on the highway in cruise and notice all settings then flip from one setting to the next and record the changes in fuel pressure and temp.
There is slight changes.
Tough to save MPG in the performance mode though : - )

 

I wouldn't hold my breath on the increased mpg. Your right foot would have more of an impact. JMO

 

That's the main reason, but I think the timing does help out on highway (for a long ways). I drove 200km, turned around and came back 200 km at a steady 100-110km/h..which is why I netted good mileage.