That was my point. 0mpg is either not moving, or a horrendously high amount of fuel being used while moving. You should have a HIGH mpg when coasting while the engine is at idle, not a zero. 2500 ft @ 0mpg with a Fit means you would have to dump the whole tank worth of gas within half a mile. Even that would still be 0.05mpg.

 

Where did you get the "100mpg" value for the .539 miles?

 

[quote=HaveaFit!;343317]You are choosing a poor model. The published data for a 0-60 mph accel is 9.3 seconds in C&D and R&T; much less 40-60. Why would you waste gas taking 12.5 seconds. I only took 4.78 seconds and then called it 5.
If you take 5 seconds at avg 50 mph the distance is 366 ft.(0.069 mi) To claim .174 miles at even 12 mpg simply isn't going to happen; 18-20 mpg would result at 12.5 seconds to go 40 to 60. My Fit struggles 40 - 60 in 5th and is very inefficient.

Also 100 mpg is too much consumption for coasting with the engine off. I did calculate on the engine being off for calculations which of course has no consumption. In my test I coasted with the engine idling just to make the test easier on my vehicle but that would not have affected coast down time. So I get .069 miles + your .539 miles is .608 miles on .0069 gal (10 mpg) or 88 mpg.
Like I said you have to use realistic model to get realistic results.
Besides Jr showed us all Sunday how well P&G works. It 'bought' him a win when it counted. The TV camera showed Jr very well using P&G.
P&G works but is a pain inthe butt on the street as well as dangerous.

 

[quote=mahout;343262]Never tried. Is that needed?

 

I don't go to WOT (wide open throttle) when pulsing... I do about 75-80% throttle, and my ScanGauge shows an average of 19mpg during the pulse.

 

well I have to fess up. as an engineer, P&G made zero sense and that was also the thought shared by a number of other Sr engineers that deal in the Thermal world in large power gen facilities. So that was why I stated the thread.

I was shown based by examples and some very simple math it did work.

I ate some crow. yummm

As an eco-man, yesterday and today I did some P&G, but not the classic way. I just ran up and down and various peak speeds of 60 to 70 and than coasted in neutral (eng on) to the point I may get in the way on I-95. It works and is good for at least 5mpg was my 1st blush at this. Real big for me was the ride home. No decent host in sight, so I just slugged along at 55 and watched my avg fall from 51 to 47. Then the host arrived and I 1 sec drafted. Than I started P&G and 1 sec+++ drafting and by the time I exited 15 miles later, I worked the avg back up to 51.

I may have a chance at a 55mpg tank real soon.

I also got tougher or more stubborn and decided no A/C today. Think my new set point for that is visible sweet on my face lol

 

An update.The info above was bogus. My SG is way off when doing pulse and glide. 17% on the fuel used

My actual millage was less than my best using my proven methods 46.7mpg P&G vss 48.14 my best.

 

This duplicates my results as well. I was being fed the same bogus data by my SG. I played around with calibration but that's not the problem; the problem is that it grossly misreports realtime and 'trip' mileage when P&G is employed. I went back to using the cruise control.

 

WDB My Sg has been spot on till now.

Get rid of the SG correction factor and do a tank witout any P&G and see what you record.

Do your miles agree?

 

By "mileage" I meant MPG. Miles driven has always been very close, within a mile or two.

I tried calibrating the gallons used via the "Fillup" adjustment but that did not change the inaccurate realtime and trip MPG numbers.

 

A gas engine has higher efficiencies with a more open throttle than the typical nearly closed throttle at steady state cruise. This inefficiency is due to having to work against a higher vacuum generated by the nearly closed throttle. The P&G technique takes advantage of the higher efficiency of a more open throttle, when combined with fuel cutoff during coast. A six gear tranny with a tall 6th gear would accomplish nearly the same without the speed variations.

Diesels do not have throttle plates and therefore would not benefit from P&G.

 

For all those on here that have used P&G in a Fit and have results post it.

I have tested it using the method described by one that posted on here and the results for the same or less avg speed was 2mpg less than my normal methods. As far as I have seen I'm the only one in a Fit to show my results based on a full tank of fuel P&G with that change only.

Also please post how you do it and be specific.

Would like to see the moderator that was on my case like a cheap suit show any data from his Fit that show results, because I never see him post any actual results like us that use the cleanmpg site and have ours on the public view,,,,,,,, Without data your just noise

 

Any time you reduce the intake air flow of a fuel metered system based on air flow (as are all engines) or shut off fuel completely while in motion, fuel consumption is severely reduced. The only time P&G doesn't work well is when the engine is left in gear during coasting as that condition slows the vehicle more by mechanical drag than aerodynamic drag. The coast time from 60 to 40 mph for my car is reduced from 35 sec to 12 when I leave it in gear but idling instead of in neutral and idling.

 

P&G Is also more suited towards cars that have a good amount of mileage.. over 50k.. it will go thru and clean out your fuel-lines and all that fun stuff.. I just threw some in my RSX type S that has 74k on the ODO.. I have not had much of a chance to test it out though.. we will see what happens.

 

Whaaaat ? Pulse & Glide is what?

 

Paul - For what it is worth:

Honestly, I don't know. I do not have a scan gauge. All my efforts have been learned by trial and error and by reading threads/forums on the internet.
I usually try to count, if I am on flat ground, letting it take anywhere from 5-10 sec to increase 10-15mph to the desired speed and then coast hoping it is twice as long(I usually count that too).
Luck has it, if you can call it that, that most of my drive has hills, so I just reach my desired speed at the peak and coast to like 40-45mph and keep a steady pace up the next hill or maintain 45-50mph up the hill if I can get away with it assuming the flow of traffic will allow me.



In hind sight, I believe you would want to track the distance traveled along with time when pulsing to the desired speed and the same for the glide to the desired speed.




I have tried this once in my wife's CRV with the FCD. I P&G from 30-40mph and I compared the same stretch of road putting the CRV on Cruise control at the P&G's average speed(happened to be 35mph and flat ground) and came up with the same mpg for both P&G and CCcases. That would seem logical to me but I do not have proof of actual improvement.

 

[quote=HaveaFit!;343317]Sorry, but P&G is very plausible. Lets say I did get 13 mpg accelerating for .174 miles so thats .013 gal. I'd say 100 mpg is low for idling, more like 200 mpg based on minimum fuel required at600 rpm no load. So by your rationale thats .00265 gal. The total is .0156 gal on which I traveled .713 miles for a total of 45 mpg. But even if your numbers were right 38 mpg is quite a bit higher than a CRX SiR that gets typically 25 to 28 mpg. The CRX SiR is a long way from a Fit but it was the only manual on hand and it is handicapped by having a 4.88 diff.
We do have a Civic HX that normally gets 40 to 45 mpg and when we get time we'll duplicate P&G with it.
Sorry but P&G is very plausible in our tests.

PS how many of the rental cars had 1600 cc engines and weighed 2100 lb. Any of those big V6's and V8's pulling 4000 lb better not get 13 mpg accelerating. In fact they are lucky to get 13 mpg overall. But with P&G they might get 20 mpg.

 

What happens when you coast 3 or 4 times the accel distance? And you use realistic fuel consumption for idling. Your model is not realistic.
If you want bias why didn't you chose they are equal?

 

mahout. Please STOP telling Fit owners P&G works when flooring it on the pulse. It works poorly for sure. I have been talking to the Fit owners that are getting the BEST Eco out of any Fit owners and they all agree. Furthermore I take great records and I tried what was suggested here and it was not as good as my best other methods. 46 vss +48mpg
P&G ONLY works well (according to the Pros) with easy acceleration to speed and FAS on the glide.



On a Fit no matter what you do, the best MPG is by:
no more than 2/3rd throttle,
2000 rpm shifts and less than 60mph to name a few things

If you have a SG keep the LOD under 80

 

haha i don't even know what pulse and glide is.
so THERE!!!
i win.
haha jk jk

but really, you guys are posting things such as "d=.5at2+VoTo"
screw that.