As I understand it pulse and glide should work at pretty much any speed. I'm trying to adopt pulse and glide but I drive on mostly 55 MPH hilly roads. If I'm in HV mode and have some EV range I find I can only get ICE shutoff below 42+/- MPH. However if I switch to EV mode as I back off the pedal the ICE will shut down at speeds up to 62+/-MPH. Switching from EV to HV while gliding at speeds above 43 MPH causes the ICE to resume turning. So I've tried accelerating to my desired pulse speed in HV coordinating releasing the pedal with selecting EV mode to begin the glide then beginning the next pulse by simultaneously pressing the pedal and mode button. Alternatevly I can stay in EV mode for the glide then floor the pedal to restart ICE but that risks getting an undesired higher less efficient ICE power level and doesn't allow lower power pulses to allow glides to begin on downgrades.
When you are in EV mode you can use EV to 62 mph if there is enough battery charge. When you are in HV mode it is effectively a standard Prius so EV only works up to 42 mph.
45'sh MPH in Gen3, but otherwise correct. OP is missing why P&G is a beneficial technique in some, but not all driving scenarios. Thus the need to read a tutorial. Hobbit is best, cleanMPG second.
Not really! Here is a tutorial: Driving technique: exploring 'Pulse and Glide' - MetroMPG.com Form which it is clear that the technique works at any speed. The Prius family "automates" the process if the top speed is 42MPH or less. I'm pointing out that by cycling the EV/HV mode button in a PIP it can be used at higher speeds. The ICE turning, zero fuel, stealth mode probably has more losses and will give shorter glides but it is all that non plug ins allow.
Yep, this is the "hidden gem" in the PiP, if you are willing to work it. I routinely get 80+ MPG on 100-mile (mostly) highway trips this way. Thank God they added that HV/EV button for the production model
How fast do you drive -- average highway speed ? I'll guess ~ 55 MPH. Is the 100 miles a round trip ?
No offense intended, I assure you. If Iluvmacs drives at the speed I suspect, P&G is not adding anything to his fuel economy. I'll show the math if he confirms my suspicion.
Highway 55MPH limit, and I'm not doing significantly more than that except perhaps on a big downhill. This is a one-way trip, but the MPG each way is pretty similar. I should be more clear in my technique that I'm using the EV-mode glides primarily on downhills and other times when speed is intentionally decreasing (i.e. speed limit goes down or coming to a stop). I don't really do highway P&G in flat areas in the "classic sense" for various reasons.
^^Thanks. Let's use 55 mph all the way then Wayne Brown has calculated that the Gen2 Prius consumes 203 Wh/mile to overcome frictions at 55 MPH BobWilson measured 64 MPG in his Gen3 Prius at 55 MPH So now we can compare your modified P&G technique to the most basic: drive EV mode until the battery is depleted, then HV mode -- all at 55 MPH. IIRC the traction battery from full to empty is 3.2 kWh, so that is worth 15.75 miles For the other 84.25 miles, the HV mode will consume a gallon every 64 miles, so 84.25/64 = 1.32 Gallons Then 100 miles consumed 1.32 gallons, for an MPG of 100/1.32 = 75.7 MPG This is well within the expected margin of error just for differences in tyres (Bob's were new), or tyre pressures, or road quality. So I'll say it again: P&G is a waste of time at highway speeds. Energy analysis suggests it might even be a bit worse. OP would be well served by understanding P&G so that he knows when it is beneficial.
Why do some insist I do not understand P&G? I take it as an insult. I'm talking about fuel economy driving HV miles, I hold EV miles for inevitable city driving. Here is my strategy for driving hilly 55 MPH roads. Use DWL, keeping the ICE in the "sweet spot" (13 to 45HP on "torque") going up and down the hills, allowing speeds between 50 and 62mph. But on longer steeper downgrades control speed build up by entering a high speed glide ie switch to EV mode avoiding regen if possible. Target speed of 62 at the bottom of the valley and 50 MPH at the crest. If you have a better strategy please share it and be prepared to defend it.
You won't have near the gains you would see relative to Pulse and Glide at slower speeds. IMO the gains aren't worth the work, but to each their own.
Well there are unforeseen consequences of using this technique! I've discovered this after posting my last tank (which used this technique when available, on about the last half of the tank) on the spread sheet. Apparently the PIP counts the EV mode glides as EV miles so my EV MPGE went up (added miles of glide) while my HV mpg went down (more fuel during pulse) but my combined MPGE went up as did my performance relative to EPA data despite cooler weather. I'm convinced the technique is an improvement as it was difference between the two tanks I've posted and it was only used for part of the most recent tank.
The longer you can remain in a state of "infinite MPG" (e or otherwise), the better both EV and HV will be. So your glide - or coasting is the key. Regenerating is nice, but it costs speed. On an extended downhill if you glide rather than regen, you won't impede traffic. And due to the Prius' low coefficient of drag (0.25), you can glide for quite awhile without losing momentum. But whenever you regenerate, you lose speed and momentum due to motor friction. So there's a bit of a choice to be made. My "to work" travel takes me from about 800 ft above sea level to sea level. So there are a few places where there's gliding to be done. But on a few steeper downhills, it makes sense to regenerate (as long as I can keep my overall speed equal to or less than 62 MPH so that I don't slip into ICE mode). And layered on top of it all is avoiding pissing off of the rest of the freeway traffic while motoring below 65MPH. It's definitely an art (as well as a science!)
I've discovered another unforseen consequence of using EV mode for high speed glides! The EV range estimate goes up! Before starting using EV mode glides my range estimate was quite consistent at about 12.4 miles. Yesterday I used some EV mode glides and this morning my EV range estimate was 13.3 miles
