Fuelly Forums

Fuelly Forums (https://www.fuelly.com/forums/)
-   Hypermiling (https://www.fuelly.com/forums/f33/)
-   -   Newbie with some questions about changing driving (https://www.fuelly.com/forums/f33/newbie-with-some-questions-about-changing-driving-8310.html)

1cheap1 05-09-2008 10:58 PM

We have a section for automatics, check it out. I have posted some info there from my 94 intrepid automatic.

theholycow 05-11-2008 04:18 AM

I wrote a [hopefully decent] summary of FE strategies that have helped me with my non-hybrid automatic.
https://www.gassavers.org/showpost.ph...4&postcount=12
I could repost it here but it's kinda long. One thing I didn't bother with in that post which might help you is a simple, free modification that you may be able to do. If your car has a cable (not an electric wire, but a cable like a bicycle uses for brakes) going from the throttle body to the transmission, adjusting that cable can make it stay in a higher gear longer when you step on the gas pedal. See https://autospeed.com/cms/article.html?&A=1304 for a complete explanation, except that article adjusts it in the other direction for people who are more interested in driving fast than saving gas.

tggroo7 05-11-2008 10:30 AM

another quick question...when you pulse and glide, how fast are you accelerating for the pulse? Like normal acceleration, moderately fast, or nearly floor it?

Project84 05-11-2008 11:55 AM

I pulse at the rate of a wheel-chair power up to 5 above the speed limit, then glide to 8 or 10 below the speed limit, if and ONLY IF, it will not downshift into a lower gear. Typically I can only P&G on 45mph roads where I get up to 50, put it in neutral, slow to 35, and put it back in gear. In my car, a '96 Saturn, under 35mph downshifts into 3rd.

Also, keep in mind, P&G should only be done (in my opinion) once the car is up to operating temperature and never in traffic or bad weather conditions. It's just too risky to be in neutral when you may need to make a fast reaction. Same goes for turning the car off and coasting... I ONLY do that when I'm traveling more than 10 miles on the highway with little traffic, do it in the slow lane only.

tggroo7 05-12-2008 12:22 PM

well I filled up my tank today for the first time after the new driving techniques...was pretty disappointed. I'm assuming I made some mistake somewhere. Maybe the last time I filled up, it wasn't as full as I thought. Anyway, I went 205 miles on 8.7 gallons of fuel for an average of 23.56 mpg...a little below my average. I don't really know what would explain it. I coasted WAY more than I ever normally did, never even used the accelerator pulling into the driveway which is something I always used to do, and even tried the P&G (tho not shutting the car off) a few times. I'm thinkin that in P&G I didn't pay attention to the RPM and might have actually lost gas mileage by doing that, but even so, I didn't do it much at all.

and Project84, what do you mean about the wheel-chair??

dosco 05-12-2008 12:38 PM

Quote:

Originally Posted by Project84 (Post 99158)
I pulse at the rate of a wheel-chair power

This doesn't make too much sense to me, after looking at the BMEP/RPM and SFC graphs.

I was under the impression that the idea of P&G was to attempt to maximize engine efficiency by:

1. Reducing losses due to throttling
2. Operate at optimum BSFC

The way I try to accomplish these things are, during the pulse:

1. Open the throttle 50 to 70 WOT
2. Keep RPMs at 2,500 to 3,000

I have an automatic, so it's a bit of a pain in the butt to open the throttle and maintain RPM without the damn thing shifting.

I've been experimenting with P&G in the last couple of weeks, at my next fill-up I'll have some mileage numbers. The last 2 times I filled up, I didn't have a "standard fillup protocol" so I'm not confident in trying to quantify the difference that my P&G technique may have had on FE.

I think the other consensus you'll find on this board is that you need a ScanGuage. I need one, for sure.


All times are GMT -8. The time now is 07:17 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.