What is P&G, or Pulse and glide or P and G?

So while on my favorite hyper-miler Forum, I realized I had a problem. While my CITY MPG’s were decent I was loosing a lot of my trip and tank average on all my highway driving.

Yea I know HWY driving should be better, right? Well that all depends on traffic and your velocity, sorry speed. My drive is not bad, while the 30 mile trek is long, I had found myself going 55MPH in the right lane, while getting a constant 48-53MPG on my Scangauge. Yes that is awesome, but like I said before it was hurting my Trip average. So back to the post at ecomodder.com. I presented the question and was kindly answered “try P&G.”

So I had heard the term before but never really understood what it was, and after 5 minutes of Googling, I found out and here is what I learned.

This can be applied for both AUTO and MANUAL transmissions, though you will see much better results with the latter.

Image from gasbuddy.com

GOAL:
The goal of Pulse and Glide is to accelerate to a point then coast the rest, hoping the amount you used “pulsing” will be made up for with the glide.

I am a heavy foot, and if it were not for the price of gas, I’d be on the pedal as much as I could, so the first part comes quite easy.

I floor it, sometimes downshifting (still working on if there’s a benefit or not), get it up to 68MPH, note my current trip MPG on my Scanguage, then shut off my car with my handy fuel cut-off switch, then I coast…… or engine off coast if you are driving a manual. Until my speedometer hits 55MPH or if I don’t have someone on my ass, 53MPH. Then I bump-start my car and do it again. Again look at the goal above. If done properly, and enough, you should little by little be bumping up your trip MPG and more importantly your tank MPG.

P&G with an automatic trans:
Rather than turning off the car, just throw the transmission into neutral, then put it back into D when you hit your low speed point. While the gains won’t be as significant, they will be gains!
Then you ask why not just leave it in gear? Well basically this comes to resistance, with your car still in gear, you are still moving your entire transmission, which can slow you down quicker.

There you have it! If you have questions, don’t hesitate to comment, and I will give you what I know from experience, not from what I have read.

This technique is talked about a lot, but I can tell you first hand it works, but just as EOC, it must be done right with proper planning.