Well, I can agree to accelerating at a good rate but not necessarily as WFO as possible. But the truth is, P&G does improve mpg over whatever steady-state speed you were doing under like conditions. On our test vehicle the results were uncontestable. A 30% gain.
I think 2000 rpm upshifts are a bit low and likely to lug the engine. Of course, the slower the speed the better the mpg as long as you're in fifth. But doing those things does yield less mpg than P&Ging under the same conditions. However, as you should note we said many times, P&Ging requires such attention to your driving and to avoiding hazardous situations that P&Ging is merely a excercize and not for reality.
What you are saying is that the best steady state driving occurs on level ground with grentle throttle changes keeping the engine under very light load and at the highest gear you can be in and do that. Thats been the hallmark of economy runs since way back in the thirties by Mobilgas economy drivers. And yes some of them used P&G to win.

 

Read this

P&G in a honda Fit and Scan Gauge - CleanMPG Forums

 

I'm not surprized you couldn't find a difference.
Didn't find a nice comparison of steady-state vs P&G consumption data, just a comparison of SG data wilth fillup data.
You need to drive 'normally' for several trips and then several trips using P&G to get a comparison. Make sure your average speed remains the same for both. (very important) Weather, too.
And upon completion compare just the SG data between the two and separately the actual fillup data for the two conditions. An overall average might be better. And it can show with statistics if one is different and then how much better than the other.
How do you ascertain the same gas fill point on each fill? It is impossible on my FIT (which is why we used a different car with manual transmission that we could actually see the fillup level on the same parking pad). Gas was weighed for measurement by hand. Thereis large room for error.
P&Ging doesn't seem to offer much for automatic transmissions because the hydraulics never shut off so there is a lot of internal drag on coasting.
Last, the scangage appears to be very similar to thr trip mpg display in many cars. The ones we have experience with has almost no accuracy in any distance less than 5 miles. Reading 'instantaneous mpg" is liable to give displayed mileage far from actual.

 

I did 4 tankfuls using a variety of P&G techniques and speeds. Same MPG as always. There is one data point for you.

Agree completely. The blasted car is a bottomless pit. And with such small total fillups, 1/2 gallon can make the difference between and .

My experience was consistent and repeatable; when employing P&G techniques in my Fit, two things occurred:

1. ScanGauge realtime and trip MPG, and gallons used (compared to actual fillup values), were optimistic by 20%+
2. I got about the same actual MPG whether I used P&G or not

 

wdb,
On this fill, I have started to P&G using what the experts on the clean form suggested it it looks better but still no 15% over many many tanks with well established Eco on this car.

mahout lead me far off base with the suggestion of WOT pulse. Not only did it send the SG fuel flow way off but as the ECU was OPEN LOOP the fuel/air ratio when rich and the Eco was worse. He does not have a Fit and his car just works different for sure.....

IF you have a SG, try what they suggested over there on the clean site. 80% max LOD on the Pulse. There's no way that I will FAS on a freeway over and over again. I'll just kick it in neutral and idle along on the glide and if the results look no better, I'll stop wasting my time.

 

Paul, from my experience the P&G every little chance you can like Larry does on cleanmpg does not necessarily yield the best mpg. I think you are heading down the right track with trying to find the right pulse rate and comparing whether or not the short P&G is worth it. It is a pain and I often screw up thinking I have shut the engine off and I go to bump start to find out the damn thing never shut off!

My hunch is that Larry, drives slow enough to get that mileage and his cooler ambient temperature he makes use of the radiator block. I think the P&G every chance he can may add 1-3mpg at best.

 

I tried several pulse techniques: gentle acceleration, WOT or near-WOT, and something in the 70%-of-WOT range as suggested to me on cleanmpg a month or so ago. They all yielded the same MPG as doing no P&G at all. I'm back to using the cruise control which I find far more relaxing anyway.

I'd be very interested in one of those 50+MPG Fit folks doing a couple tanks worth of everything-but-P&G hypermiling, just to see if they see a difference.

I think my biggest mileage gains will come from convincing myself to slow down even more than I already have, but I'm extremely reluctant to trade time for money. I have a long commute, and getting 10MPG better mileage works out to about $500/year in savings. Amortizing that over the length of time I commute comes to about 80 cents an hour. Being home longer is worth far more to me than 80 cents an hour.

 

wdb - I have, look at my last 2 tanks.

The 56mpg was every trick in the book with P&G like it was going out of style with no A/C - I have no SG though

The 49mpg was no hypermiling only driving below speed limit and cruise control using A/C sparingly.

 

You got a 14% increase on the difference of two tanks of unknown miles and conditions traveled. Thats significant.

One of the things posters here are not realizing is they are probably using P&G techniques when they are trying to maximize mpg at 'steady' speeds. You can apply P&G to an upper speed of 51 and a lower speed of 49 just as effectively as using 60 and 40 to average 50 mph.

I went back and checked some tests run some years ago with a 1500 cc engine on our dyno. At idle the fuel consumed was 0.6 gal per hour. At max rpm 6000 and WOT consumption was 6 gal per hour. At 2400 rpm 2.2 gal per hour at 10 hp (about what is required to run 50 mph on level ground). At 2400 rpm max hp was 28.
A comparison of fuel consumed on 12 sec acceleration and 36 sec coasting compared to 48 sec steady speed at 2000 rpm leaves .0225 gal consumed at WOT and .0006 gal on coastdown at idle (total of .0.0231 gal)compared to .0293 gal consumed at steady 50 mph. So P&G is verified.
I verified against stochimetric equations for the combustion of toluene with air to see if the dyno numbers made sense. You may note that 48 sec at 50 mph is a total distance of 3520 ft (.667 miles). MPG for the 2 cases would be 28.83 mpg vs 22.7 mpg for the engine tested then. The difference is 27%.
Curiously the same % increase as our test on the CRX which has a 1600 engine but much higher gears ( 4.88:1 w/ LSD in top gear).

 

Did some testing today and have an update.

P&G with 60 max and 50mph min on 80% of my trip I-95.
The Glide was eng "ON" in neutral at idle
The Pulse was slow acceleration with SG max load "LOD" at 80 or less.

A-B-A test

A 3 miles of P&G 53mpg
B 4 miles at steady 50mph 48mpg
C 4 miles P&G back to 53mpg

Looks like +5mpg or +11%

I trust the SG data is good as it has always been with closed loop operation.

If this helps + rep me.


I'm 100% sure this will work for you if you want one way P&G will work on a MT FIT and you have a SG to keep an eye on LOD.

 

I'll wait for the fillup numbers.

 

wdb
Interested in a little wager my SG on this fill will be within 2% of the actual and baring any need to drive different +50mpg???

51 miles on this fill and SG says 52.5 mpg also fuel gauge is still far from full mark. I should have the miles to that event Wed. That will back up what I see going on.

 

We need to have a FIT mpg contest like the real hypermilers do.
I couldn't drive that way for an extended period of time.

 

you would win. Your the Master

 

No, Larry is the master with his damn 60+mpg! I swear he doesn't go over 45mpg! I don't think I will ever reach 60mpg without a SG. I don't know if I want to pay for a SG just to reach 60mpg because I know I will not always drive slow as hell.

I can't wait to see your results on the P&G.

I am tired of this damn 100 degree weather - 3 days in a row!!! - more like FAT camp in my car with no A/C. - My wife says my car stinks now because I sweat so much in it - NOW THAT IS A MANS CAR!