P&G freeway tested ABAB +14% FE

[California98Civic]

Actually the test was B-A-B-A if A is always supposed to be an “unmodded” run.

PURPOSE
To see if I can do a standard P&G technique I call “GLEN” (Glide, Load, Engine-on, Neutral) on the freeway for significant FE benefits, preferably convincingly beyond possible “noise” of 1-3%. I have a 5.7 mile uphill freeway leg on my regular commute that I cannot route around with practicality or with sufficiently beneficial FE effects to justify the extra distances. Typically, I have scored low/mid 40s on this stretch by driving slower than is legal. Even then, this leg still brings down my averages. If I had a good solution, I could bring my averages up and not risk a ticket for too slow driving.

METHOD
Simple. Same time of day with roughly similar temps day-by-day over a one week period. Wind quite regular (absent) day to day. Drive one day with hypermiling, then the next day without, repeat until I have six runs minimum. The P&G technique used an acceleration arc from 55mph-65mph at 80% load. I then coast down to 55 again, seeking a 60mph average speed during the run. Up the steepest hills, I ranged from 55-60mph in the acceleration arc seeking a 57.5mph average. When doing the straight driving runs, I did my best to hold a steady 60mph, which was very tough in hilly terrain. Climbing the steepest hills I reduced speed to about 57.5. I never used EOC or any other hypermile method, such as driving in the slip-stream.

RESULTS
“A” = with P&G and “B” = without P&G
A – 51.2mpg; ave 59.8mph.*
B – 45.0mpg; 58.8 ave mph.
A – 54.9mpg; ave 57.1mph.
B – 47.7mpg; 58.1mph.
A – 54.5mpg; 59.0mph.
B – 44.9mpg; 58.9mph.
*I forgot the exact mph number at the close of the run but this is close to correct.

“A” averages = 53.53mpg @ 58.63mph
“B” averages = 45.87mpg @ 58.60mph

“A” is 7.66mpg HIGHER than “B” or 14.31% better.

Random confirmation is suggested possibly by a 22 mile run I took the other day on the freeway, using this GLEN P&G method. I got 63.4mpg at nearly 60mph. Under normal conditions a month ago I could have seen maybe 52mpg on that run. Maybe only 49.

[skyl4rk]

Thank you, this is very helpful.

Is the whole course uphill?

What is a typical glide time between pulses?

[SentraSE-R]

Very nice results.

[PaleMelanesian]

Thanks for testing this. I already knew P&G gives great results, but you put it into numbers.

[Andyb04]

Just to clarify, engine is on the whole time, right? Also how did you measure engine load, is it a scangauge function?

Seems like P&G is a lot of work, but if you practice enough it may just become habitual. Thank you for the results!

[euromodder]

Originally Posted by Andyb04

Just to clarify, engine is on the whole time, right? Also how did you measure engine load, is it a scangauge function?

Load (LOD) is a standard ScanGauge function.

When referred to on ecomodder, Pulse & Glide is traditionally without the engine running during the glide part.

So California98Civic uses GLEN to differentiate his engine-on technique.

[toc]

Glide, Load, Engine On, Neutral?

Pulse & Glide = Get the car up to speed, and glide to a lower speed, and then accelerate again.

I would Glide with the car in the highest gear, unless I was looking to build momentum, in which case, I would glide in Neutral.
Pulse - I would pulse up to the speed limit.

Can someone explain for me what Glide, Load, Engine On, Neutral is exactly?
How does this work up hill - if you glide uphill, you'll lose momentum and have to get it back - and in many hills that momentum is gone as soon as you get it?

Ahh: Found this: Introducing "LOG"

Still, how does that work on hills exactly?

[Old Mechanic]

Originally Posted by toc

Glide, Load, Engine On, Neutral?

Pulse & Glide = Get the car up to speed, and glide to a lower speed, and then accelerate again.

I would Glide with the car in the highest gear, unless I was looking to build momentum, in which case, I would glide in Neutral.
Pulse - I would pulse up to the speed limit.

Can someone explain for me what Glide, Load, Engine On, Neutral is exactly?
How does this work up hill - if you glide uphill, you'll lose momentum and have to get it back - and in many hills that momentum is gone as soon as you get it?

Ahh: Found this: Introducing "LOG"

Still, how does that work on hills exactly?

P&G is currently defined as accelerating at higher engine loads, followed by coasting with the engine turned off. Restart and repeat.

The only difference is he is leaving the engine running instead of shutting it off during the glide.

You could use PNG-on and PNG-off to differentiate. Many AT equipped cars should not be coasted with the engine off as it can damage many transmissions.

Hope that helps you understand.

regards Mech

[Vekke]

Originally Posted by California98Civic

Actually the test was B-A-B-A if A is always supposed to be an “unmodded” run.


“A” is 7.66mph HIGHER than “B” or 14.31% better.

This should be MPG? Anyway nice test. I have observed on my driving that P&G is at least 10% better...

[toc]

I was trying pulse and glide today on the freeway, I'd accelerate to 105kM/hr, and stick it in neutral leaving the engine on (at those speeds I think engine off coasting is disturbing), it doesn't take long for it to drop to 90kM/hr, and then I need to get back up to 105.

That's what I thought a Pulse and glide cycle was - if so, what am I doing wrong as surely, you aren't sitting there on the clutch every 15 seconds engaging gears (or in EOC, starting the engine)?