Hypermiling Question

[SentraSE-R]

The Ultragauge shows instant, trip, and average mpg. You can reset the latter two whenever you want. I reset the trip mpg when I reach my destination and when I return home. I reset the average mpg when I refill my gas tank. So my trip mpg tells me trip mpg, and my average mpg tells me tank mpg.

[DonR]

I don't see as large a difference between Neutral & drive as a few folks posted. I definitely do see a difference though. The Wife's Hot Rod goes from about .6gph to .4gph. The Scangage isn't allowed in her car, so that's using the factory gage. In my Suburban I go from .6 to about .54.

One thing to remember is that the automatic transmission is still pumping fluid around being ready to be used when in drive. This takes energy to do. Putting it into Neutral pumps less fluid requiring less energy. The main throttle plate stays in the same position but the idle air control valve (much smaller butterfly on the side) is being opened to try to maintain rpm.

Don

[SentraSE-R]

There's no reason to run the engine at all when you're stopped at a red light. Turn it off if you anticipate being stopped >7 seconds. 0 gph is a lot better than .2-.4 gph idling.

[JohnnyRun]

That makes a lot of sense, but I wouldn't want to overwork the starter motor too much. I'm thinking of going with the Ultragauge then... Does it say GPH like MetroSchultz mentioned in his reply? I'm sorry to be asking so many question, I just want to make an educated purchase! And do you have to set it up once you connect it to the car?

[SentraSE-R]

Since I started hypermiling 40,000 miles ago, I've saved $1700 compared to getting EPA combined mpg estimates. That's more than enough to buy a cartload of starter motors . I calculated that idling at a 2 minute stoplight can drop a ten mile 30 mpg trip average down to 28.5 mpg.

Yes, the UG can display instantaneous GPH, average GPH - general, and average GPH - trip.

[JohnnyRun]

Woah, thats an impressive figure :O So you haven't had any problems with your starter over the years?

[PaleMelanesian]

My Odyssey also does better in Neutral at a stop. .45 gph vs .6 in Drive.

A warm-engine start is very gentle on the engine and starter. My civic (manual, so the idle in N vs D is irrelevant) has 185,000 miles on the original starter, ~40,000 of that with serious hypermiling. It's fine.