Can hypermiling techniques burn more fuel?

[comptiger5000]

I experienced something like this with other people today. I'm sitting at a red light, Jeep in Neutral. Light is about to go green, so I go to put it back in gear. Right as I finish moving the shifter, light goes green. Before I even have time to get my foot off the brakes, guy behind me is sitting there *beep, beep, beep, beep* about 5 times.

And I wonder why when I'm coasting to a stop, people fly up behind me, obviously stepping on it pretty hard, get close, then realize what I'm doing and nail the brakes wasting a ton of gas...

[ShadeTreeMech]

I don't have an instant MPG meter on my cars anymore, but I know in my cars that did have it, going slowly in 3rd or 2nd, even at low revs, were trumped by nearly any reasonable speed in overdrive. Doesn't make a lot of sense to me, but I know I always tried to get into 5th when I had a stick ASAP (or 6th gear, on my motorcycle.)

For that reason, I'd love to get both my vehicles longer legs. My Maxima spins well over 2k rpms at 65 and the minivan is geared even lower than that. I know in 3rd the maxima's rpms are exactly calculateable according to speed; to wit, 3000 rpms is 60, 3500 is 70, 2500 is 50, etc. So if the speedo ever went out I could very accurately figure the speed by going into 3rd.

While I know there are gears that can be exchanged in an automatic, I'm not savvy enough to do it myself, and shudder at how much it could cost to get someone else to do it for me. And if I could only hack into the computer of the Maxima (and minivan for that matter) I would adjust the shift points, or wire in a switch to stay in OD despite the throttle position. With an auto it is difficult to allow yourself to slow down and just lug it up a hill when your right foot needs to go down more to even have a hope of making it up the hill, and the act of opening the throttle will cause your computer to downshift the tranny.

[ShadeTreeMech]

PS comptiger, what engine do you have in that cherokee? I thought many of them had a decent inline 6 in them that fetched good economy. Even my Explorer got 15 mpg regularly, and that was with the lower tech gas guzzler 4L from the early years.

[SentraSE-R]

Here are the data from my family's three cars. The left-hand bumps are P&G figures. The following dips are next-to-top gear mpg. The remainder of each graph line are the top gear mpg figures at different speeds. One gear down from top gear at 30 mph beats top gear at 55 mph in all of my cars, with the possible exception of the AT Elantra. It should in your cars/trucks, too.

[ShadeTreeMech]

I appreciate someone telling me I'm wrong, then proving it. It means i have to work harder for the rebuttal

Not having any equipment to prove otherwise, I'll just have to agree with you. And it is something to remember when driving. I knew that MPH destroyed MPG, just didn't realize it was so drastic.

[ShadeTreeMech]

Correct me if I'm wrong. Looking at your cars listed, and your chart, I assume you have a Sentra, and you were able to increase your top end MPG by removing the wing? Is your high rise tail light in the wing like it is on my Maxima?

[SentraSE-R]

Originally Posted by ShadeTreeMech

Correct me if I'm wrong. Looking at your cars listed, and your chart, I assume you have a Sentra, and you were able to increase your top end MPG by removing the wing? Is your high rise tail light in the wing like it is on my Maxima?

Yes, yes, and yes. I plan to redo the spoiler tests soon, doing ABA back-to-back.

Thanks for the thanks, BTW.

[orange4boy]

My experience is that my hypermiling generally saves gas for everyone around me. Even on two lane roads I usually end up with a few cars behind me all driving slower, happy to be paced by whoever is in front. On one lane roads I usually drive the limit so I'm saving the followers gas there too. There is the odd situation where the odd jacka** floors it and passes me but that was his decision.

Shadetree,
Sounds like you are a perfect candidate to install the TCC lockup switch so you can stay in lockup in 4th way down in the RPM range, speed and load. It's a game changer for automatics.

[ShadeTreeMech]

I suppose down here people are too impatient; driving slow generally guarantees getting tailgated, which sadly pisses me off. (Did you all see the Mythbusters episode where they proved driving angry causes yyou to burn 1/3 more fuel?)

I need to read the wiring diagram for my Maxima and Villager, which incidentally may have similar trannys. On my Explorer introducing a ground to the wire going to the TCC from the computer harness would lock it up in 3rd and 4th. 2nd and 1st would be bypassed, which was handy. Anyone familiar with the late 90s Maximas?