I got antsy and decided to fill today instead of waiting until tomorrow.
That's...an interesting finding. The ScanGauge reported 40.0mpg on this, and the result was higher as expected. (Tested engine braking and zero key starting after FAS on this tank, to recap.) Thing is, it's way higher. I need to do some serious sanity checking and probably another test tank or two before I actually draw a result from this. The needle is well above the "F", at least, so I know it wasn't a dramatic underfill. Hand calculations, hooo.....
Might have already done it but check you parameters on the setup in the SG. Mine reset once and it reset the engine size to the default setting which made the MPG inaccurate.
Does your SG die when you EOC or is it hot wired?
Did my monthy trip to the adjoining town today. Segment high on the FE 41.8. Previous best 40.5. But I left the fishing pole at home this time. Lucked out with the traffic, no pile ups that are usually scattered along the route.
So you cut out key starts but still bump started? Just making sure I have things correct here.
And also, previously the scangauge was overregistering but now it's underregistering? Muy interesante.
I cut out key starts entirely (except for when I begin a trip) and only bump started when I did cut the engine, but I also cut the engine far fewer times. Instead, I took a neutral ICE-on coast and used engine braking when I needed to dump speed or stop.
I did some hand calculations and I think the whole thing may just be stupid measurement error. See, my previous tank showed 42.0 on the scangauge but 40.4 on the hand calc, which I figured out might be attributable to the ~220 or so key starts over that 552 miles. But now I have a tank that was 40.0 on the SG and 43.2mpg with hand calc, which would mean that the ScanGauge failed to register ~0.76 gallons over 412mi. The problem is there's no way to attribute that to the ScanGauge measuring idle consumption rates rather than zero consumption. That 0.76gal is equal to roughly 2.5 hours of idling, and there's no way on earth I spent 2.5 hours moving with the throttle closed.
The other troubling (though telling) bit is that the 40.0mpg for this tank and 42.0mpg for the last tank average out to 41.1mpg, and the hand calculated 40.4 and 43.2mpg average out to 41.6mpg. (Yes, I did those averages the right way by calculating gallons based on average consumption.) That's very close...a 1.2% underreading on the part of the ScanGauge, which is in line with what I have observed in the past.
I regret that this whole thing is likely to be badly confounded by pump error. It's usually very consistent, but appears not to be in this case. I don't see how I can draw any conclusions at all about key starting or engine braking even though the numbers support the theory. I'm back to square one, and I have half a mind to average those numbers in the gaslog so that I don't have this probably errant personal record tank sitting there. (In all likelihood, the last tank was.)
I've decided to declare pump error as the cause of my weird tank averages. As a result, I've gone into the gaslog and re-distributed the gallons the way I think they were actually burned according to the ScanGauge averages. Turns out the previous tank was a PR of 42.5mpg (as I thought it should have been) and my "experimental" tank was a ho-hum 40.4mpg, which makes perfect sense given the lousy condition and half-hearted hypermiling.
I'm back to pushing it as of this morning. I'm slightly less aggressive about codfishing/fas/EOC/whateveryoucallit but that just means I'm eliminating the few engine kills that result in a very short coast followed by a key start. That's more to mitigate wear on the clutch and starter than anything else. I'll be saving the brakes a bit as well because I have started using the bump-start-->engine brake-->stop-->go routine. Makes for busy hands and feet but it should result in some killer numbers.
I've decided to declare pump error as the cause of my weird tank averages. As a result, I've gone into the gaslog and re-distributed the gallons the way I think they were actually burned according to the ScanGauge averages.
That's fair - I've done it before. An erroneous small, "under fill" gave me a record tank, and a lousy subsequent tank. So I added the 2 together and split the difference. It all works out in the end (this was with my previous car).
Anyway, you're quite a consistent driver, looking at your MPG chart.
I've stayed silent to now, but no longer: we shouldn't really be calling it EOC, because then what do you call engine on coasting?