Interest in AFE Group Buy????

I avg. 500 miles a week, almost all highway

 

Surprising results. I haven't lost any mpg with either.

 

My mileage seems to be down a bit(more than 1 MPG over several tanks) since removing the secondary air filter and installing the AFE. Will continue to monitor for a few more tanks before reinstalling the old setup.

 

About 2.5 tanks on the AFE ...and I haven't seen any mpg benefits.

Traveling hasnt' been consistant enough this past tank to justify positive mpg results (if there are any).

 

My travel has been consistent and I've seen no MPG benefit after 3 tanks. I immediately noticed that the engine doesn't lug as much at the low end. I would think that the MPG boost would happen immediately also if it exists. It doesn't make sense to me that the engine would take a while to notice that I had an air filter in it before using less fuel since the injection mixture is computer controlled.

Same thing for synthetic oil. If I've replaced the oil with gas-saving synthetic oil, it should be evident the moment I put it in. If it's not, something else is going on to boost the mileage of those who testify otherwise.

 

hard to duplicate results based on conditions. only a scangauge can prove if your getting better MPG and according to some members it does....I'm already getting a bug to sell the AFE drop in and get an AFE stage 2

 

I'd have to disagree with you on that one. I've driven back and forth on the same route to work for over a year, monitoring my gas useage at fillups, and my mileage has been consistent (15.5-16.5 if I baby it). With the air filter in, it's in the same range. A scangauge shows instantaneous MPG. That's much more variable than calculating MPG because you can affect it just by involuntarily adjusting your foot while you drive. The best way is calculating from tank to tank based on the number of gallons you pump in and the number of miles travelled. It doesn't matter what the scangauge says because those two are hard numbers that don't depend on a device (given of course that you haven't changed the wheel size). I believe the scangauge can show you where you could improve though.

 

Scangauge also shows avg mpg for the trip, day, previous day and tank.

I think that would be more accurate than just tank to tank gallons to fill. Maybe you park at an angle one day and the pump clicks off sooner putting in a gallon less than last time. There's no way you can drive EXACTLY the same way each time or pump gas exactly the same each time either.

 

95% of the time I fill at the same gas station and almost aways at the same pump, as it's near my place of employment and it's usually uncrowded when I'm there.

As for it's accuracy, the scangauge can't be more accurate. Your scangauge has to be correctly calibrated as it's result is based on an average of your instantaneous mileage numbers (it's an estimation). It's using a curve fitting function. You're supposed to use your actual gallons pumped to calibrate the device at each fillup (which is no different than the manual method). It will then introduce a fudge factor to get the device closer to the actual usage.

So [actual mileage travelled]/[gas pumped] will always be more accurate since that's the number the estimation is supposed to be based on. The scangauge may get close to the real number but it will always be off. If you're not calibrating at every fillup, then your readings are not accurate. If there is error in your fillup method, the scangauge will only compound that error.

See page 18 of your manual for the procedure. From the manual: This screen should be used every time the vehicle is refueled.

http://www.scangauge.com/support/pdfs/SGIIManual.pdf

 

So? Do you control air pressure? Temperature? Humidity? Anything else than can alter one pump from another? Do you use the same pump each time? If you can do all that, more power to you. If not, a more accurate system would use constant monitoring of the fuel actually used, not put in the tank.

 

I probably modified the original post you quoted when you posted. I answered it there.

 

To update:

I initially did not have an increase. However, two weeks ago I reset the comp and I've gotten 18-19mpg vs. 17-18mpg prior, a 1mpg increase. It's pretty small but we'll see how it is as time goes on.

 

The scangauge doesn't know how much fuel is actually being used either.....

 

So how does it figure it out then?

 

YOU HAVE TO KEY IT IN... that right there is why i havent' bought one.

 

That's only for the fillup. It that would affect how much gas is IN the tank, but without some other factor would NOT tell you much much has LEFT the tank or how fast it leaves.

 

After doing hook-up and setup....you have to run some gas through the tank and fill it up again to get a *fuel adjustment* percentage (baseline %). Without that initial baseline run of fuel through the tank - the Scangauge will only GUESS your fuel consumption and the MPG's won't be accurate at all.
Don't ask me how it GUESSES fuel usage. It's hooked up to the truck computer, so it's got all sorts of data available to use.

And even after that baseline % is set....each and every tank after that... you need to *fine tune* that percentage as you go to get it the Scangauge more accurate. That Fuel adjustment % changes based on the galloons the scangauge guesses you've used versus what you actually put in the tank.

 

The Scangauge accuracy is still based on the amount of gallons you've put in the tank each fillup. The inaccuracy of the scangauge versus manual calculations....is that the Scangause is using the PREVIOUS tank fillup to calculate the future/current tank MPG.

When doing it manually - you're getting a realtime MPG for the last tank (just getting that data after the tank is empty).

 

I'm just thinking it must get a figure from somewhere since it'll do realtime mpg readings fresh out of the box without entering any fillup info. As in, just plug it in, and enter engine size. I've switched mine from the truck to the car and forgotten to change settings. IIRC, the mpg was off at first until I remembered to change the engine size from 4.0 to 1.8 (and a couple times since then from 3.0 to 1.8 after reading engine codes for a friend). So obviously it's not a straight mpg or gph number from the ECU, but must be some other figures it uses to do the calculation.

I doubt it uses the last tank for real time readings as I've gone from the truck (20mpg) straight to the car (40+mpg) without entering a fillup, or reseting anything other than engine, tank, and tire size. If it used the previous tank for readings then I would think it would take at least 1 tank to adjust to the car's higher mpg.

 

When you used the Scangauge on the car - did you calculate the MPG manually and compare with what the scangauge was reading?

I always calculate my MPG manually each tank. I'm old school. It's just a way for me to see MPG and verifies the accuracy of the scanguage.

Last winter when I was hauling 200lbs of sand in the bed for 3 months - The scangauge wasnt' accurate at all and I was adjusting the fuel % each month as I was suppoed to. It was frustrating and I was ready to complain about the unit. Then - after removing the weight and making one final adjustment to the fuel % - it's been pretty accurate ever since. Again- another reason why I always do MPG manually at the end of each tank.