Interest in AFE Group Buy????

Yes. I manually check the car when I fill it up and it's accurate enough for me (given a couple decimals and rounding differences) when I fill it all the way. Thing is, the manual option is ONLY accurate when you fill the tank full. If you put $10-$20 in here and there when you get cash, then the manual method goes out the window. Same for the tank-specific options on the scangauge, but that's irrelevant. I use it more as a NOW gauge to adjust driving habits to maximize mpg. If you can do all that in your head while driving then you're a better person than me.

And honestly, driving 300-400 miles before seeing your MPG results is almost useless. Do you remember how you drove the entire time? Sure, 1 long trip maybe, but that's 5 days worth of commuting for me. I don't remember if I was stuck behind someone doing 45 on Monday by the time I fill up on Friday. Or if I passed people, or was in a hurry one of those days. Having the number right there in front of me whenever I drive is better, and gives me more consistent results. Instead of trying to drive the same way 1 tank at a time to see what helps. And to me that's more accurate because I can monitor myself and keep things more consistent. Like if I see mpg drop, I'm driving too fast or accelerating too hard.

 

The manual method doesn't go out the window if you only partially fill. As long as you keep track of what you put in and don't reset the odometer until you do fill. Then you add all the gallons you pumped and use the total miles travelled from the last fillup when you finally do fill.

For example, lets assume you get 20mpg from previous calculations. Lets also assume you used 10 gallons and travelled 200 miles. If I put 5 gallons in one day and the odometer read 300 miles, then 10 gallons in another and the odometer read approximately 500 miles (100 miles from the first 5 gallons + 200 miles from 10 gallons + 200 miles from your last fillup) and then fill with an additional 10 gallons later on, the total miles on the odometer would read 500 miles and you would have pumped 25 gallons (500 miles/25 gallons is 20 mpg).

No one is saying that the scangauge's instantaneous mileage calculations are not valuable. I think they're very valuable because it shows how you're driving at any one moment in time affects your overall average mpg. But that doesn't mean the scangauge is more accurate when calculating your average mpg.

You're really arguing a different point here. You're saying the manual method can't help you to adjust your driving method because you can't remember how you drove over every point in time. I don't think anyone made that claim. The tank-fill method is an average to be sure and differences in driving style will affect your overall average mpg (which will be reflected in the average). Those are usually just small points in time which get smoothed out over the whole span of the tank.

When you calibrate the scangauge with your actual fillup numbers it gets more accurate. The curve it uses to calculate your instantaneous mileage will improve as you enter more data in. The scangauge can't take into account inefficiencies in your burn rate. It also just has a couple engine size parameters. Our truck is a 4.0 liter but that's not necessarily exactly 4.0. It could be a slight difference that is rounded to 4.0 for marketing sake. Some engines have a different number of cylinders yet are still 4.0s. For example BMW has a 4.0 Liter V8. That cause the gauge to be off. It's probably a good guess, but that's why you need additional info, so it can adjust.

As for the v6 4.0 liter vs. 1.8 liter, there is some logic built into the scangauge which guesses approximately how much you're using. When you enter new information from your fillup, it's able to get closer to what you're actually using in any moment in time (it adjusts the curve). However, moving your scangauge from one vehicle to another will definitely mess up the accuracy of the instananeous data as you're mixing data from one engine with another. The scangauge doesn't have separate data points for each engine type (separate fudge factors but not separate historical data). It's possible it resets the historical data when you change the engine type but it's an unknown.

 

To update my mileage since the AFE, I was about to put the old filter back in, but decided to reset also. My first tank was back to my old mileage numbers, about 27 MPG. It had dropped to about 25 or so. Me happy now.

I feel every one should unhook the neg battery cable. This seems to be the ticket. Also I noticed that my rough running for a few minutes just after startup has disappeared.

 

^it's good to know your mileage is coming up. Odd that you had to reset though... I never did that with mine.... Just swapped one night after work, drove to work the next day, and noticed the difference on the fill up at the end of week.

 

Maybe someone with a descent number of miles on it and who hasn't swapped out the filter for the AFE could reset their computer to see if it affects gas mileage. Maybe reseting the computer forces it to recalculate something (air fuel mixture?) that wasn't changing over time like it should. It could be a bug in the software.

 

I finally did a mileage check after having a few tanks through my AFE. Today I clocked 19.7 mpg on the highway on my 06 DC 4WD V6 auto w/ 21k. According to my sorta organized records, that is the best I have done. Oh my secondary is still installed fwiw. Not sure where that lands in the grand scheme of things, but I like the AFE. Never reset the ECU either.

 

Where is the best place to purchase an AFE Pro Dry Filter for my 2009 4.0L V6?

eBay has them for $65 shipped. Any other options?




Sorry, I just realized I resurrected an old-ass thread

 

any difference in just replacing the stock air filter with afe drop in?

 

Other than not spending $20/air filter every time the OEM one needs to be replaced? I picked up 1-2mpg with it. Might be a little more responsive now. I mainly wanted to say $$$ on air filters. The mpg increase, and better response are just bonuses.