Pulse and Glide Technique

[SUNSETFOX]

A while ago, I came across an article about using Hyper-miling technique "Pulse and Glide" on EV's and some in that forum argued that it doesn't work because of aggressive regenerative braking that "kills" momentum. But the e-Golf, with the option to set regenerative to zero in D, seem to be a perfect EV to glide. Sure enough, I experiment this technique over the last few months and saw my highway average increased from 3.7m/kmh to about 4.0-4.2m/kmh with the average speed around 60-65 mph. I only use this exclusively on highway or long uninterrupted stretch with D as the default and occasionally switch to D1(more like pulse and drag!) for slight downhill to control speed and recharge the batteries. My Pulse to Glide ratio is about 60/40 depends on situation. For city driving, I use B or D1-3 most of the time. My overall average m/kmh for a year of ownership is around 4.3m/kmh in hilly Seattle. Anyway, I am just curious if anyone in this forum has tried the "pulse and glide" method with success and would like to share their experiences too. Would like to hear from you! Thanks.

 

[tbier]

I leave it in D and just coast as much as possible. If I'm in stop and go I use B. When I am coasting and know that I will need to stop I drop to D1, then D2, then D3 as I approach. Cruise control on highways is great that it keeps you to your set speed with regen on downhill. This is great on steep declines but I turn off CC and coast on slight declines to gain KE/speed and then coast back down to my desired speed. Regeneration (or recuperation) is great but it will never stare as much PE as the KE you have coating along. I've had my 2017 SE for a week now. 800 miles on it and I'm averaging 4.8m miles/kw. Very happy with it so far.

 

[SUNSETFOX]

Thanks for your feedback. I wonder if you would consider trying Pulse and Glide to see if you could see a difference. I'd like to see how others think of this technique. BTW, 4.8m/kmh average is very good. That's what I get in the Summer here in Seattle when the temp. goes up to 60 degree or higher. On a few good days, you might find getting 5 or above is very possible.

 

[Verkehr]

P&G, as I understand it, improves efficiency from shutting an IC engine off and minimizing the total revolutions it does (glide) and when it is running, it avoids pumping losses by being kept under load (pulse).

However, the e-golf does not have an engine and its motor can not disengage. Nor does it suffer from pumping losses under light load. In fact, the power electronics are more efficient under light load (i.e. less waste heat). When coasting in "D" mode I've noticed through diagnostic software the car regens slightly (~500w) which is still subject to the inherent inefficiencies of regen.

I've observed that steady state driving is most efficient, especially at low speed. Driving a steady 20 mph with a light foot on the accelerator, the car can achieve as much as 7 mi/kWh in warm weather.

 

[JoulesThief]

I drive with a light foot accelerating, and drive all Blvd's, stop lights and stop signs. Speeds up to 45 mph, usually as close to 40 mph as possible and timing the lights to get most of them green. Then stop signs, 13 of them on a foot hill type road through most of NW San Fernando Valley in Los Angeles, CA. I am pretty consistent, with windows open or closed at 6 to 6.3 miles per KWh indicated. Car shows 119 to 122 miles of range in the summer time from the guess -0 -meter. I drive in D mode, and only shift to D1 when far away from red lights to time them to change so I lose the least amount of momentum

 

[SUNSETFOX]

Thanks for all the insightful feedbacks. For non-highway driving, I second most of your suggestion to keep a light pedals and keep the speed below 45 mph with a steady speed. However, my initial question is about highway driving where keeping an average of 55 mph or above is necessary. I've found out that, for example, in order to maintain 60mph average, it is more efficient with pulse and glide (accelerate to 65 and then coast back to 55, then go again) than keeping a steady 60 mph all the way.

 

[SUNSETFOX]

Found this interesting article about pulse and glide in EV to share. Not sure if the result is objectively conclusive but the initial observation echo what I experience.
https://speakev.com/threads/pulse-and-glide-and-hypermile.16932/