Hello--
I will be getting my new 2007 Prius in 2-4 weeks. I am busy trying to learn all I can regarding maximizing my mpg in this interesting vehicle. Can someone give me a simplified version of how to accurately practice the "pulse and glide" driving technique? I take it that it takes practice! My main daily commute will be one on interstate, generally at a speed of around 70 mph, for a total of about 25 miles/day. From what I've read, this is all more applicable for trips where one is going 35-40 mph, but I do know it can all be applied to the general freeway commute as well. Thanks!

 

For it to be effective you have to travel at 30 to 40 mph. This is not effective for freeway speeds. Nor is it effective if your area is hilly.

 

Resist is correct that it can't be done above 40 MPH. But there is a somewhat similar high-speed technique called "warp stealth" that may allow you to squeeze out a few extra MPG on the freeway. See this writeup for a detailed description of both P&G and warp stealth.

In addition, P&G can be used at speeds below 30 MPH. In fact, a Japanese driver got what is apparently the highest documented Prius tank MPG to date (112 MPG), mainly using P&G between 21 & 34 MPH on her commute.

P&G also has limited use on hills. Not on a sustained steep uphill. But gently rolling hills may actually facilitate P&G more naturally and allow you to maintain a more consistent speed than on flat terrain. You can pulse uphill with more gradual acceleration or steady speed, depending on the incline, than on the flat. Then you can glide downhill and instead of losing speed like on level terrain, you can maintain or even gain speed. Gathering momentum on the downhill may help carry you up the next uphill.

You're right; it takes practice ... and patience. But the results could blow you away after awhile. I've been working on my technique for months. My round trip commute today of 54 miles netted 85.9 MPG with extensive use of P&G on a mixture of rural, suburban, and urban routes (no freeways) -- much of it at speeds of 25-30.

In any event, enjoy your car!

 

You might also take a quick read of the Prius FAQ for some of the easier techniques. Also, don't worry about the "dealer tank" mileage.

GOOD LUCK!

Bob Wilson

 

I read it was 116 mpg. Another Japanese driver also got 115 mpg.

 

Before I fetched the link for my previous reply, I was thinking it was 116 too. But the linked article of course cites 112.

Darn it! 112 looks so lousy in comparison.

I hadn't heard of the 115 MPG'er, that I recall. Do you have details or a link?

 

http://www.chicagotribune.com/busine...i-business-hed

 

Thanks, Resist!

 

There are lots of thoughts and debates on this topic, but here's a simple summary I've tried to put together. (Disclaimer - I am not a hypermiler and don't have a scangauge, etc.)

0-20 mph (i.e. traffic jams, parking lots) - use battery if possible (using the EV button if you have it).

20-42 mph - Pulse and Glide (basically, minimize battery use). Using Neutral is OK for gliding.

42-60 mph - keep instantaneous MPG between 25-75 except when you can use Warp Stealth on downhills or when slowing down (or use slight battery assist to keep gliding longer). Don't use cruise control or neutral.

60-70 mph
Flats: use cruise control to keep constant speed
Minor hills: Speed up on downhills, slow down on uphills, keep instantaneous MPG between 25-75
Major hills: Try to keep engine from going into high rpm regime, if possible.
Warp stealth on downhills , and use B only if battery is full.

70+ slow down.

I'm sure there are many refinements (and corrections) to this, but I'm trying to give a simple version of high MPG driving. Again, I'm not a hypermiler, but I do consistently get higher MPG than my wife, who drives at similar speeds but doesn't use these techniques.

 

Karkus did a pretty nice write up. I have a couple of minor comments but his write up pretty well covers the field.

Below 42 mph, I like to drop down to 38 mph because this gives a 'guard band', some margin, away from 42 mph. Being below 42 mph is good and above 42 mph is good but transitions through 42 mph can lead to unnecessary fuel burning. I also prefer to know I'll go at least a mile above 42 mph. At 38 mph and below, you'll really get excellent mileage.

Ordinarily when in the 38 mph and slower range, I like to hold the speed constant and let the ICE automatically cycle on and off. It is effectively a built-in 'pulse-and-glide' but at a constant velocity. I'll often let the car run on cruise control and watch it cycle.

At speeds above 45 mph, I like to get just a bit over my target speed and then drop back to the target speed. This seems to quickly get the car into "energy recirculate" mode, the Prius equivalent of 'over-drive.' Call it 'getting on the step.'

GOOD LUCK!
Bob Wilson