Problem with Pulse and Glide.

[JockoT]

Today I had an 80 mile journey on main A roads and decided to give Pulse and Glide a try. Now, at present, all I have to indicate my fuel consumption is a trip average indicator which is factory fitted to my Jazz.
What I found was, if I accelerated up to 55 mph and removed my foot from the throttle, it was only a matter of seconds before the speed dropped to 45 mph, the slowest the traffic, and my passenger (wife), would accept. The vehicle barely weighs a ton. I tried 60 mph and 50 mph, which was a bit better for length of glide, but my consumption indicator started to drop back. I also found it made for an uncomfortable trip, as the transmission does not feel all that smooth going from acceleration to deceleration.
The reason I opted for 50 mph as a minimum speed was the fact that my rev counter dropped to around 2000 rpm and I was trying to keep in DFCO mode.
I found that the best fuel figures seemed to be with a light throttle and engine on coasting, on reasonable downgrades.
Once I get a ScanGauge fitted I will be able to make a better judgement, but have you guys got any tips or comments that may help?

[jonzobot]

I don't do it myself (too much traffic where I live - and I don't want my inconsistent speeds messing with other drivers). But I understand you do not want to be in DFCO for the glide. In a manual you want to be in neutral. You glide further this way and actually, paradoxically, you burn less fuel over the trip even if it's just to idle the engine during the glide - because you glide longer.

[JockoT]

I've seen both methods advocated on the net. Until I get my ScanGauge I don't know what will work best for me. I may just have to pulse uphills and glide down.

[Gasoline Fumes]

DFCO is only good if you want to slow down or control speed going down a steep hill. Glide in neutral! I rarely use pulse and glide on flat roads. I haven't found it to be much benefit in a light, underpowered car. On flat roads, i just cruise at about 45 MPH. Most of my gliding/coasting is either downhill or to stops. If there's nobody behind me, I'll coast to a stop sign without touching the brake pedal. Engine off.

[JockoT]

Thanks. Basically that's what I have been doing up until today. Except I keep my engine running.

[puddleglum]

I only use DFCO when I'm slowing down to stop. Coasting in neutral is much more effective on the highway. IMO, P&G isn't going to help a lot unless you are going to EOC. I usually just drive with load on the highway if I have to worry about offending drivers or passengers. That means just enough throttle to crest the hill and coast or speed up on the other side. It was only after I installed my kill switch so I could EOC easily that I've started to see P&G really work. Even then, I haven't seen the benefits of a hard throttle pulse like most suggest. See what works for you and do that. Be patient, it's a ongoing learning experience.

[JockoT]

Originally Posted by puddleglum

it's a ongoing learning experience.

And don't I know it! I have had good results to date by maintaining steady highway speeds, coasting down hills with engine on, using DFCO when I need to slow down and avoiding the brakes like the plague.