How do YOU Pulse and Glide?

[101Volts]

In the 2000 Dodge Caravan 3.0 Litre model, I recently started Pulse and Gliding since the ScanGaugeII was calibrated more accurately. It's a very useful form of hypermiling IMO, When done right and if your vehicle can glide long enough.

On the recent trip from the gas station to home, When pulsing, When I did pulse and gliding depended on the traffic around the van; If people behind were too close (And I did come close to tailgaters frequently, They might still be around for a while yet) I kept a fairly constant speed as low as 40-45ish until they had a safe zone to pass and did pass (And some people passed when I was going the speed limit anyway).

Once there weren't any cars around I'd pulse to the speed limit or as close to it as I could when on a down slope or a fairly flat area, Keeping corners and such where I couldn't see traffic in mind to not possibly wreck. When pulsing I accelerated between 11.5 and 13.3 according to the MAP gauge. At the moment I don't know where the MAP reads at full throttle so I can't say that. The same trip had a maximum RPM of 3938. Sometimes I'd accelerate 5 MPH at a time with a glide of a second or two in-between, To give the engine a short rest.

After I got to the speed limit of 55 I'd glide. In some instances I was pulsing to 55 and gliding down to 35 and even 25ish up at the top of some hills, And I did sometimes push the gas pedal while going up a hill so the van wouldn't lose as much speed. A car accident is something I don't need, Imagine someone going 55 (Or is speeding) and I'm going 25 just around a corner; This might result in a crash so if you do this, Check your mirrors to see if you have enough time to have an extended glide before pulsing again.

I prefer a very wide berth while hypermiling and in rural Pennsylvania I've managed to get that.

Oh and I managed an average of 39.1 by the time I parked the van at home, or so the gauge read. I do like to fill up at about the 5-gallons-used mark though.

[Xist]

I only pulse-and-glide in light traffic. In moderate traffic, I try to P&G within 5 MPH, but I would probably be better off maintaining 55 MPH or whatever is noticeable. If I can, I accelerate from 50-70 as hard as I can without my automatic downshifting, shift to neutral, and coast back down to fifty. I should do an A-B-A to see what kind of difference that actually nets me, because I do not think that it is big, while I am pretty sure that using cruise control on level ground would be a great deal easier on the system.

The Phoenix area is very flat. When I drive out-of-town, when going up a steep hill, I accelerate as hard as I can without the automatic downshifting, although that would be too fast on a moderate hill. If hill goes back down on the other side, I usually start coasting before I crest, because I can accelerate 40-50 MPH in neutral. Once I am going faster than I want, I shift back into gear, and downshift, if necessary.

I often weave all over the road, changing lanes when there is a car behind me, but not in the next lane, although if someone starts tailgating me, I shift to neutral, move to the right side of the lane, and wait for them to pass me.

If they honk, I coast in-gear.

[sbestca]

With my 2012 Grand Caravan there is no point in putting the transmission in neutral any more. With the 6 speed there is little holdback in gear and it usually shuts the fuel off when you let off the throttle. There is little point in exceeding 90kph/55mph (due to wind drag) or dropping below 50kph/30mph (due to downshifting). Hills are best handled by cresting at 50kph and accelerating to 90, then letting off downhill, then accelerating to 90kph at the bottom and holding just enough pedal to crest at 50kph again. This is a different technique than other vehicles I've had.

Ironically I followed a heavily loaded cube van who was following this pattern due to his load. By drafting him (at a safe distance) I was able to break 40mpg(imp) on a tank. By slowing down to no more than 100kph, P&G, and drafting I am regularly seeing tank averages in the 35+mpg(imp) or 7 L/100km range on highway driving.

Steve

[Xringer]

When I pulled out the rear differential, drive shaft and short shafts out of my old 99 Honda RT-4WD CRV,
I found the cruise control started doing a P&G on it's on..
Without the engine being loaded down by the rear-wheel drive,
the CC was over-shooting the setting.
Then it would slow down back to the set speed.. Auto-P&G..
(It was 'chasing' the speed setting).
Then, I tuned up the cable tension a bit and got it running smoother.
But before that, it only ran smooth going uphill.. !
And once when I had it loaded up with 400 pounds of lawn much.

So, if you have an older CC with the old cable setup, maybe you can add
some slop in the line and get Auto-P&G..?.

[Xist]

My car does not do DFCO, so I use neutral when possible.

[sbestca]

Originally Posted by Xringer

SOME CUT
So, if you have an older CC with the old cable setup, maybe you can add
some slop in the line and get Auto-P&G..?.

Short answer, no.
P&G requires planning based on terrain and long coast periods.

Steve

[Fat Charlie]

Badly.

The pig I'm driving has more rolling and aero resistance than any 10 cars ought to have. That leaves me either really low speed P&G or gliding on pretty steep hills. Anything else isn't cool- when you're "only" going the speed limit on the highway and your rig decelerates as quickly as mine does, P&G just isn't happening.

[sbestca]

Yeah, I tried it with a moving van and it was impossible. Let off the gas and it instantly lost speed like brakes had been applied. I did find a "Rolls Can'ardly" driving style gave a better fuelmileage readout on the moving van. I used moderate pedal to just barely get up the hills and kept the same pedal to accelerate up to speed limit for the next hill. Basically just kept nearly the same pedal at all times and allowing speed to drop going up hills.

Steve

[101Volts]

Originally Posted by 101Volts

(Long quote by myself posted on 2013-09-02)

I'm not sure it's working in the Caravan so well now. Perhaps it does work but on 2013-09-13 I was pulsing much more gently. The ScanGauge II was wonky and not calibrated properly when I posted that prior quote.

Edit: Why say something if I have nothing to say?

[sbestca]

Yeah, the 2012 Caravan does not respond well to traditional Pulse and Glide.
It seems to work better with more underpowered vehicles.

Steve