I know this sounds crazy, but my fuel mileage recently jumped from 13-14 mpg to 17-18 mpg.
The ONLY modification was.........
Switching from Shell to Chevron.
Who would of thought that the brand of gas would make such a HUGE difference ?

 

Ha. Right. You're calculations must be off. You're not going to gain 4 mpgs from switching from Shell to Chevron.

 

Is this by pencil, calculator, information center or other? I use a Scan Gauge II which will do instantaneous or any other type of MPG calculation you want and since it operates off the OBD port, I trust it completely. I too, have my SERIOUS doubts about the change in mileage from Shell to Chevron. Maybe .5, but 4.0 MPG, I don't think so.

 

Must have been some pretty poor Shell gas, water in tanks, maybe loaded with extra alcohol, etc .... to jump like that. I find that the 17-18 is easy to do with BP with "invigorate" .... it's what I use about 90% of the time with some Exxon thrown in. Road trips of 20 miles or more, I often see 20-21 in my '07 5.4 w 3.55 rears and stock Perellis. I also run 1oz. per 4 or 5 gallons TC-W3 in my fuel now.

I find that the ScanGauge II in AVG MPG readings, if one travels keeps it on from fuel stop to fuel stop without causing it to reset .... is always within a tenth of a mpg of what I compute using old school math and my miles devided by gallons. It s reading GPH and MPH so if tires and veh are calibrated, and time is constant, it should be right.

 

It is also the time of year that they switch from winter to summer blends. That could have something to do with it. I average 12-14 in winter time and 14-16 in summer.

 

I believe him because I have had an increase in MPG also as I use both brands but noticed an increase when I used more Chevron. I thought it was winter gas or something but I am getting 15 mpg all the time versus 13 to 14.5.

 

Oh, I believe him too. I've used some "not so good" gas before, got a tank that you'ld swear was water .... and I've seen times when one tank just seems to be "super gas".

 

Could be the difference in the percentage of ethanol in the fuel. It says on every pump that the range is anywhere between 1 and 10 percent

 

There are a lot of things I like about the SGII but one that I really like is the instantaneous MPG. It will really show you where your bad mileage habits are. It also shows what it takes to get that behemoth rolling. In town mileage is not good. With very many stop lights you can get about 10 MPG. On the open road, flat and a steady 70 MPH I can get an instantaneous of at least 20 MPG. That is absolutely ideal conditions W/ 5.4L & 3.73 axle. Anything at all touches that ideal and it drops. You probably wouldn't enjoy the ride much if you were trying to keep it on that 20 MPG continuously.

 

Instant MPG is like the vacume gage I used in other vehicles to "tune my right foot" for max MPG, it will improve your "bottom line" $$$ wise.

Instant MPG is "top left" on mine, AVG MPG is "lower left" and I leave "top right" on speed so I see it as I see mpgs, and "lower right" is engine temp usually. I play with the ones on the right, cycle through things like trans temp, cyl head temp, OSS, percent slip, gear ratio, etc .... some as I drive though. Have all 24 X-gages with codes for older and newer FoMoCo OBD II readings. Amazing, and with a splitter one could see 8 at same time with two SGIIs if so inclined.

I never use that "miles to empty" feature as I stop and fill up at about 1/2 tank as a general rule. In many instances, over a couple hundred miles runs fill up to fill up, with steady foot, 5.4 and 3.55s with SC FP 1865 87 Perf Tune .... I've seen 20-20.5 mpg by SGII and math.

 

I believe my wallet.
It is heavier these days due to the lower fuel consumption.
I am going by the information center.....AND the pump readout.

 

12.2 all day long, uphill...downhill...with trailer or without.... least my truck is consistent.. LMAO

 

i just changed my fuel filter.....

 

I have noticed my mileage went up recently as well. I actually had my best tank yesterday. I got over 370 mi for that tank. For some reason using Kroger gas has extended the mileage. I was averaging around 15 or now I am doing over 16. Which in these trucks is big.

 

Agreed...