Let's talk WAI

[drifttec101]

The PT cruiser and the Neon share basically everything including engine blocks! Good job on saving the $$. Yeah 47 is a lot, it would be about a 33% increase over EPA. Plus, I can't really reduce weight because I have to carry supplies back and forth when I make the trip. At the very least monitoring my fuel consumption while driving the long distance keeps me awake.

[theholycow]

Reducing weight won't necessarily help anyway. There's a link in my sig about it. In short, most cars do not gain any FE from weight loss, especially if driven by a hypermiler.

33% over EPA is easy in my VW, and not impossible in my GMC (which has an automatic).

[Jay2TheRescue]

Originally Posted by drifttec101

What I'm going to try is this... remove the fenderwell air box and close the hole that is left there between the engine and the fender. Then take the stock underhood airbox top off. Now my filter will be exposed to underhood air. The only problem with that is the the crankcase valve line requires suction that will be reduced if I unseal the top of the underhood box. Will that be a problem?

I did this on my 98 Sierra. Better than nothing, and the only expense was a few pieces of duct tape to cover the original intake. I've been meaning to fab up a better WAI, but I've been lazy.

[Ford Man]

I've seen people reroute the intake air tube from the fender well to a warmer area underneath the hood and use that as their WAI.

[Project84]

I got 46mpg for a tank average after a HAI and interstate driving. The SG was reading like 47.7 or something before the off ramp, but then a little city driving pulled me down to 46 for the tank.

My car is supposed to do like 31 highway... so quite a jump. I was driving from Cleveland to Cincinnati which geographically is a slight downhill slope I think. I did mild drafting and kept the car in gear the whole time. No A/C and ambient temp was like 80-85 w/ AIT being 140's I think?

The detailed info is in my gaslog.

[severach]

My two theories are:

1) The increased temperature makes more of the fuel charge burn early in the stroke making a higher percentage of the energy produce forward motion.

2) The increased temperature shifts the Scangauge MPG higher even though there is no real increase.

Why move the IAT sensor? Run it with a variable resistor and set the temperature to anything you want. It won't take long to figure out what the IAT does.

[GasSavers_BEEF]

many of us use the scangauge as an indicator but use our gaslogs to verify a change (negative or positive) of a particular modification.

many things throw the scangauge off but pen and paper calculations are pretty accurate (especially over many tanks)

the IAT sensor reading doesn't mean much. it is part of a closed loop system where the 02 sensor adjusts the feedback. regardless of what the IAT is reading, the 02 will adjust the A/F ratio to a stoich mixture (or go to open loop where you are running rich)

[Jay2TheRescue]

I think the intake air temp sensor just helps the engine cope with varying temperatures more quickly. Adding a resistor will only produce a short term gain as the engine computer will start to get lean readings from the O2 sensor, and it will relearn how to operate with the skewed data.

[theholycow]

Originally Posted by BEEF

many of us use the scangauge as an indicator but use our gaslogs to verify a change (negative or positive) of a particular modification.

many things throw the scangauge off but pen and paper calculations are pretty accurate (especially over many tanks)

The Scangauge is great for giving you live data and encouraging you, but it is NOT an dependable way to record your fuel economy.

Pen and paper calculations are not merely "pretty accurate" over many tanks; they are 100% accurate. After all, they are based on the actual fuel you used and the actual miles you drove. What could be more important than the fuel you used and the miles you drove?

[GasSavers_BEEF]

nothing is 100% accurate.

the gas pump only goes down so many significant digits as does the trip odometer. the degree of error is very, very small but there is still degree of error.

some portion of the gas is either not accounted for or fabricated and some mileage the same. even though it is 0.000X of a gallon and 0.0X of a mile

the assumption is that in averaging the numbers, they will even out but there is always some small fraction of a percentage that you are off from the actual.

sorry for overthinking this one