The single most important improvement to FE you can ever do. FREE.

[CO ZX2]

Originally Posted by diamondlarry

This is the conclusion I came to soon after I got my first SG. The SG is a great tool but, as great as it is, there are so many variables involved that you can't get an absolutely 100% accurate reading ALL the time. You can get it dialed in pretty close but you'll never always be dead on. I use the SG for measuring improvement over different segments and the hand calcs when topping off the tank as the final word. As for those who were criticising CO XX2 recently, Carlos is right, when you analyze things as carefully as Carlos has, CO ZX2 is doing even better than he was reporting. It's all about the commute conditions.

diamondlarry. Are you still using your injector shutoff? If so, does your ScanGauge go to 9999 MPG in Gauge Mode when you shutoff to coast? If not what do you see? It would also be interesting to know your MPG reading in Current Trip mode during shutoff. Do you show any GPH used during shutoff?

According to Ron DeLong 9999 is the expected preferred reading and they work to achieve that in cases where needed. I appreciate your info, just trying to understand how a few various cars are different than most.

[diamondlarry]

I only see 9999 in instant mpg mode for a very brief time right after I bump-start the engine at the end of the glide. While it is gliding, I see what appears to be the speed x* readout. Current trip mode just shows accumulating mileage as usual.

[CO ZX2]

Originally Posted by diamondlarry

I only see 9999 in instant mpg mode for a very brief time right after I bump-start the engine at the end of the glide. While it is gliding, I see what appears to be the speed x* readout. Current trip mode just shows accumulating mileage as usual.

diamondlarry. Thanks. What do you see for MPG during your glide before you get 9999? What I meant to ask of in Current Trip mode is the MPG reading during glide. You should be showing a steadily rising MPG number as you glide. Also do you show a reading of GPH in Gauge mode when injectors are shut off.

Have you talked with DeLong about your SG? What does he say?

[diamondlarry]

Originally Posted by CO ZX2

diamondlarry. Thanks. What do you see for MPG during your glide before you get 9999? What I meant to ask of in Current Trip mode is the MPG reading during glide. You should be showing a steadily rising MPG number as you glide. Also do you show a reading of GPH in Gauge mode when injectors are shut off.

Have you talked with DeLong about your SG? What does he say?

In instant mode I see, for example, 550, 540, 530, etc. as my speed falls. It seems to be .1 gphX speed. In current trip I see a rising mpg number as you mentioned. When I'm gliding with the engine off the GPH shows .1 GPH. I haven't contacted Ron but it sounds like it may be a good idea.

[BumblingB]

Now if I just had hills big enough to do this on, our hills are very gradual around here. Enough to suck up gas going up, but barely enough to glide down and see much of a difference........... I have ONE hill that I can drift down .7 of a mile IF no one is behind me because at the end I am at a crawl - again, very gradual. That being said, I do live in the highest point of Florida - yep, the Florida mountains.

[skewbe]

Originally Posted by BluEyes

...I think the best way to run this test would be to do the neutral coast first. Mark where the car falls below 30mph and then on the engine-off, in-gear test, restart the engine and continue driving to the point where the neutral coast ended (but at what speed???)...

I think you are homing in on it here, the trip back up shouldn't really factor into it if it was a different trip for each test. Even just in practical terms, the store isn't going to move 3.6 miles farther away just because you are coasting in neutral, and you are not going to just fire up the engine and turn around if your engine in gear coast didn't make the distance.

I retract my suggestion of firing up the engine on test 1, a matched terminal speed if only examining the downhill legs is a sufficient reference point.

The fact that it went 3.6 miles farther is significant.
The fact that the second test averaged 20mph faster is also significant.
The fact that it was on top of a mountain is also significant
I don't know that we learned enough to make a mpg comparison though (didn't actually use any fuel).


CO, I'd love to get your mileage ratings. You have to cover a lot of ground out there so it's especially awesome that you are making those kind of numbers.

[The Toecutter]

I wonder if a diesel or electric would respond this way?

My hunch is that a diesel would, but an electric wouldn't. The losses for an electric drive tend to increase with load(P=(I^2)*R)

[cfg83]

diamondlarry -

Originally Posted by diamondlarry

I only see 9999 in instant mpg mode for a very brief time right after I bump-start the engine at the end of the glide. While it is gliding, I see what appears to be the speed x* readout. Current trip mode just shows accumulating mileage as usual.

That's exactly what I see. I wonder if the instant RPM jump from 0 to 1000+ throws off the implied "0.1 GPH" failsafe in the software.

I think this is a question for the ScanGauge guy. Also, why not go to 0.01 GPH? Is this just a display thing where we ScanGauge only wants to express x.x digits?

Question : Would switching to metric units for ScanGauge usage yield better accuracy in the ScanGauge because the liter as a unit is smaller?

Todo List : 1.00 Gallons equals 3.79 Liters. Therefore, 0.1 Gallons equals 0.379 liters. This would imply that for the "0.1 GPH" scenario, the ScanGauge should display "0.4 LPH" (assuming roundup). However, IF the ScanGauge displays 0.1 LPH (a failsafe value for a different unit), then the "KPG" calculation would be more accurate for engine-off strategy.

This would imply the need, for accuracy, to use the ScanGauge in "liter display" mode and convert as needed, .

CarloSW2

[diamondlarry]

I will give the Metric thing a try today. I'll also see if you can switch back and forth without having to convert back to gallons.

[CO ZX2]

I'm in Daytona. FE is pretty important here sometimes, especially with 1 or 2 laps to go. No coasting here till you're out of gas.