First full tank with ScanGauge!

[ThermionicScott]

...and also my first full tank since joining EM and adding a few tips/mods to my repertoire. I saw the gas light on my way to work today and knew it was time. Filled up on my way home (it's only 5 miles each way) and got 24.8 MPG. Looking back through the log book, my previous first fills of the year were 22.3 (2016), 23.5 (2015), and 17.9 (2014), so I'd call it a success.

Usually, January has my worst tanks of the year, but my last few tanks have been trending upward. I credit the added lower grille block and regular use of the block heater for getting my engine up to temp faster and keeping it there, and the ScanGauge for showing me how much further I can coast in neutral before the waste of idling overshadows my forward progress. Previously, I didn't let my speed sag too much before figuring I should add more momentum.

Subarus make it tough to achieve good gas mileage for a lot of reasons, but I think a goal of averaging 25 MPG over the winter and 30 over the summer may be doable with more practice.

- Scott

P.S. I have to give myself a demerit over the ScanGauge "fillup" procedure, though. It underestimated my fill by more than a gallon, but I accidentally saved the fill before correcting it. D'oh!

[Daox]

Congrats Scott. To see an average increase during some of the worst winter weather is a great start!

[ThermionicScott]

Thanks Daox. I was going to mention that without rigorous A-B-A testing, I'm not sure which mods/techniques are helping me the most, but after joining here, I got too excited by the possibilities to test everything individually. I just figured I'd do well to start applying the proven stuff ASAP.

[skyking]

the A-B-A thing makes for great science, but I personally go A-A-B-B-C-C-C-D and so on. I don't allocate time for that "going back" thing, when we have a great repository of working mods here.

[JRMichler]

I'm another user of the A-B-C-D-E-F-G method of modding and testing for the same reasons that Skyking gave. I'm up to mod H if I count the vacuum gauge as a mod.

[skyking]

Thanks to the solid numbers you got with your beautiful aeroshell, people build them with confidence. That recent wood one is a great example of that.
If a person follows along, bellys when they can, keep the diffuser angle below 4~5%, reduces unnecessary cooling flow, they will get results.

[ThermionicScott]

Second full tank under the tutelage of my ScanGauge. I scored just shy of 25 MPG. Was hoping for better, but I'll take it.

I had used the ScanGauge on my dad's pickup when I borrowed it to haul some things last month, and so the SG estimated I'd used a few extra gallons of gas. Without really thinking, I adjusted the fill amount downward. In retrospect, I shouldn't have done that -- it'll probably overestimate my MPG now, won't it?

[ThermionicScott]

Both excellent points, Old Tele man. I did reset the engine size both times, and I should have gone halfway on the adjustment at the very least! I ran some errands this afternoon, and the MPG readings were quite literally unbelievable. I wish it were possible to adjust the calibration between tanks...

[oldtamiyaphile]

Originally Posted by ThermionicScott

Second full tank under the tutelage of my ScanGauge. I scored just shy of 25 MPG. Was hoping for better, but I'll take it.

I had used the ScanGauge on my dad's pickup when I borrowed it to haul some things last month, and so the SG estimated I'd used a few extra gallons of gas. Without really thinking, I adjusted the fill amount downward. In retrospect, I shouldn't have done that -- it'll probably overestimate my MPG now, won't it?

Personally, I prefer to adjust the engine size parameter to get my SG as close as possible, then use the tank calibration for fine tuning.

It's a good idea to write down the calibration when swapping to another car so you can always go back to it.

[ThermionicScott]

Originally Posted by oldtamiyaphile

Personally, I prefer to adjust the engine size parameter to get my SG as close as possible, then use the tank calibration for fine tuning.

It's a good idea to write down the calibration when swapping to another car so you can always go back to it.

How far off from the actual engine size are you willing to go before leaving it up to tank fills for calibration? I've just been using the spec size of whatever vehicle I've had this thing on. If the SG reports optimistic MPG numbers, would you fudge the engine size up or down from reality to steer it in the right direction?

Thanks.