when you guys say "way more" mpg ...can you quantify that...is that like 2 mpg better or 5 or what? What would be helpful is noting

(1) mpg improvement seen in the timing setting (fuel saver setting)

and

(2) mpg improvement seen in the timing + fuel setting (performance setting)

Both with quantitative numbers i.e (1) 2 mpg and (2) 3.5 mpg

 

when you guys say "way more" mpg ...can you quantify that...is that like 2 mpg better or 5 or what? What would be helpful is noting

(1) mpg improvement seen in the timing setting (fuel saver setting)

and

(2) mpg improvement seen in the timing + fuel setting (performance setting)

Both with quantitative numbers i.e (1) 2 mpg and (2) 3.5 mpg

 

I was seeing like 27+mpg in the performance (timing+fueling) setting. This reading was coming from the ScanGauge II (scanner that plugs into OBDII) so I wasn't convinced. When I re-filled and checked by hand the mileage was closer to 23mpg. Still very good but not what I thought.
Anyway, I'm going to run the next tank in the mileage (timing only) setting and check it by hand also. I think what's happening is the XZT+ is fooling both the engine ECU and my scanner.
Mike

 

23 is still very good

Is there a way to reset the overhead MPG reading on my '01 ...it computes over the life of the truck and I'd like to re-set it when I refill so I can get a measure of my mpg more accurately...

 

Hold the mode button and the metric/american button at the same time until it resets.

 

The overhead is not very accurate. The more box power you have, and or the bigger injectors you put in, the more falsely it reads. That is why the XZT+ guys think they get better mileage with the fuel and timing aggressive mode. Heck, with my Jammer 5's and Edge Juice turned up to level 6, my overhead will read 30-32 mpg when I cruise down the freeway at 70 mph. When I fill up and hand calculate, i really get 19-20. Before when I had RV 275 injectors, my overhead would read 26-28 mpg, and hand calculated at fill up was usually around 20 mpg. The more juice you flow without the ecm knowing it, the more incorrectly the overhead will read.

When my truck was bone stock with 265 highway tires, overhead would read 24.5-24.9 mpg and hand calculated at fill up would always be 22-22.5 mpg. My point is that when you add fuel, the ecm usually does not know about it.

 

I agree with Big Blue24......I hand calculate every tank full and thats how I know I get better fuel mileage on the timing only setting than I do on the Timing / fuel setting. Besides' my truck didn't come with one of those niffty overhead computers.........

 

Thats because only the cool kids got 'em