Official Thread for posting daily FE updates

[GasSavers_brick]

Originally Posted by SVOboy

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.)