Video: how to Pulse & Glide in a Prius - 85 mpg!
 

Made by Darin and me with Doc Willie's help, of course :thumbup:

http://www.youtube.com/watch?v=MAocwToZWVQ

Does the Insight work anything close to that?

Did he say how to do it in a... regular car?

Not really, unless you have MIMA and can FAS, as far as I know.

No, he's got a prius :)

Anyway, darin and I are going to make a video of this in his metro at AMEC in a little under 2 weeks, so stay tuned for the "pulse and glide a non-hybrid" video

PS: It's actually 720p, but youtube is still rendering the video

Unfortunately, the camera battery died before we actually finished taping all the segments we wanted to get for this video.

So you didn't get to see the fuel economy display showing 85 mpg achieved in this P&G demo by Doc Willie.

Or our discussion of "Are there times when you wouldn't want to use P&G?" (Answer: yes, of course.)

Did you do that video?

I shot and edited it.

Can I watch it please?

Nothing is stopping you

The Insight works like a regular car. You have to shift into N and kill the engine yourself. But it does roll better than most cars, and the engine restarts very smoothly.

Is Doc Willie a forum member?

Nice video. I don't use P&G but I studied it in 2007. My results comparing the equivalent constant speed and pulse and glide:
http://hiwaay.net/~bzwilson/prius/pri_PnG_040.jpg
The test track I used:

34 36' 04.80"N 86 37' 50.44"W
34 38' 20.94"N 86 37' 44.64"W

In normal driving, I use something resembling pulse and glide in the first 1-2 miles of my morning commute during the engine warm-up when the engine never stops. ICE fuel consumption during warm-up when the car is in "N" is about 60-70% of any other gear. So as I cut through my neighborhood, I shift into "N" as much as possible to let the engine continue warm-up with minimum fuel burn. I'll also shift into "N" if approaching a red light but otherwise, I don't 'pulse.'

Bob Wilson

so in a REGULAR DINO GAS SUCKIN HUNK of Aluminuum and STEEL.....lol.....
lifting my foot of the gas, would also require me to shift into Nuetral.....which is what I do. However, I have never turned of the engine. I might turn off the engine in a much old car..(my 66 mustang comes to mind)

Don't think so.

Except for the fact that you never said you uploaded it, and I can't find it.

It's embedded in the first post of this thread.

lol, I didn't specify enough. I wanted to see the Pulse and Glide non hybrid video.

Oh, that. I don't know if we ever got around to it? I haven't had a driving car for 6 months so there you go...

I see, thanks anyway.

Very nice. I drive a National Park Service Prius as a volunteer, and would love to get 85+ mpg with it.

Drive at 18-20 mph on relatively flat, paved roads with minimum winds.

Bob Wilson

I took a 2007 Prius out for a test drive today at a local dealership. I drove an 8 mile route, and got 77 mpg on it. The salesman was more than willing to go out again, as he'd never seen anyone get such good mileage on a test drive. The second time around, I only got 67 mpg. Still, that's 72 mpg for 16 miles - pretty good for my first attempt at P&Ging a Prius.

I would have loved to P&G the first gen Insight. (at the dealership)

What was the big difference between the two runs?

P&G works just dandy on a non-hybrid, too. ;)

I took a 1st-gen Insight 5spd for a run once and maxed out the display at 150 mpg. 15-30 mph p&g with eoc, for a 16-mile round trip.

I got 50 mpg driving to the dealership in my Scion xB, and 54 mpg driving home, P&Ging. It's about 15 miles each way.

No difference between the first and second runs in the Prius, except the vagarities of traffic, and loss of concentration on my part.

Well, I went back to the dealership this week, and took my wife. The '07 Prius I'd been looking at was sold, so the salesman let us drive an '08. I took it halfway - about 4 miles - on the same route I'd driven before. This time, we did it in the dark, with lights on and three people in the car. I got 75 mpg. I switched drivers with my wife, and she drove back. But first, the salesman (same one as last week) took a picture of the fuel consumption display, he was so impressed.

My non-hypermiling wife drove us back, and got 45 mpg. That's pretty decent, as I struggled to get 36-37 mpg in my SE-R driving to the dealership and back (about a 40 mile trip), compared to its lifetime average of 38 mpg.

Any guess that it would work on a Honda IMA setup (CVT Automatic)?

First, the question, "Is it safe to EOC a CVT?"

Next, would the battery drain in the IMA example and require a similar amount of gas energy to charge?

RH77

I think (and I'm really no expert) the IMA in your Insight is very similar to the 2nd gen Civic's IMA setup. When you want to 'coast' the car either goes into neutral, or the engine cams basically use a vtec mode that allows to engine to pump but never compress air. This vastly reduces pumping losses but still allows EV propulsion, however there is still drag from rotating the engine.

The answer is the same as the answer to the question "Is it safe to tow the CVT Insight with four wheels on the ground?". So, I dunno.

And yes, P&G will save gas in any car that can coast with the engine off. The key will be to glide as long as possible (down gentle hills is the only place I bother), and accelerate as efficiently as possible. I think the right way to do that in the CVT is with gentle action on the skinny pedal, so as to keep RPM's down.

Off topic: the 2010 Insight's "EV mode" still has the gas engine rotating, but with all 8 valves closed to reduce, but not eliminate, frictional losses in the engine.

I really don't think the two are the same.

When you tow, you tow for miles and miles... how often do you coast even one mile? There's a huge difference there. The fluid in the bearings isn't going to dissipate that fast, I hope.

Just my opinion, though. I think people look too far into it when they're asking if a vehicle is safe to flat-tow when they're considering EOC.

To continue off-topic (briefly) I have been searching for more details (without success) on how this engine works. Is there a good source you recommend? Thx...

RH77

First you have to understand the average speed is the critical component. You can get 80 MPG in a lot of cars if your average speed is 22 MPH.

Second in regards to a CVT Insight. All last summer I managed close to 80 MPG in my daily 38 mile round trip drive after warming the engine up. My best was 83 MPG one way, while averaging 40 MPH through over 40 traffic lights.

The CVT will climb very shallow grades at over 55 MPG, with acceleration that is very very gradual, measured in several seconds per MPH increase in speed, while climbing a very very slight grade, measured in a few feet per 10th mile.

Then on the very slight downgrades the instantaneous mileage will jump to 125-150 if you allow the car to very very slowly decelerate. The other traffic on the road will hardly notice the changes in speed because they are microscopic.

The best summertime mileage I got in the CVT averaging 55 MPH was 70.2 MPG for 577 miles in one day. Mostly daylight, with absolutely no accessory loads whatsoever.

I don't do engine off coasting in the Insight, not interested in wrecking a 5k transmission.

regards
Mech

I got that tidbit from some car magazine, but there's always Honda's website.

You can try cruising the forums at InsightCentral, but the modifications made by current 2nd gen owners tend to be window tint, stereos, interior lighting, blah blah blah.

I found the same on specialty sites: a whole lot of nothing. I did find a helpful video on the Honda site that describes the LDA-Series 3-Stage VTEC and IMA system (for what I assume is for both the HCH-II and 2010+ Insight). It didn't discuss the dual ignition per cylinder, but there is lots of documentation elsewhere. The search terms of "Insight" and "L13A" or other engine terms yielded a bunch of fluff. I only assumed the Civic setup was similar, which apparently it is.

Unfortunately, most of the Insight's details are marketing ploys, blogs, and games. It was refreshing to finally figure out how the "EV" mode worked! (thanks for the re-direct).

Apologies for the "off-topic" folks -- the thread is now resuming regularly scheduled programming, already in progress... :)

RH77

coasting is fine in most modern vehicles as when you take your foot off the pedal as long as the revs are above idle no fuel will be injected into the cylinders...................just leave the car in gear and take your foot off the pedal.

I have a CVT and it has a wet clutch. Coasting should be fine in it as long as it is in 'drive' - it depends on the gearbox but in my case this allows both cones to rotate. This will turn the engine over but also pump oil onto my primary cone (which is connected to the engine side) - and you really do want a lubricated cone! If the cone were to remain static with no oil that could easily mean damage being done............

If it's in Drive, that's not coasting. You're describing fuel-cut engine braking. That's useful in it's place, like coming up to a red light or down a mountain. It's not useful for Pulse & Glide.

my apologies - I stand corrected!

I think in terms of a CVT the engine will need to turn over to drive the hydraulics, so it is necessary to keep it in drive. This again depends on the design of CVT.

unless of course you install a manual clutch inbetween the gearbox and the engine but that is a different story all together!

leaving CVT aside - on a manual you could mod it for pulse and glide.........

simply install a switch that turns the injectors on and off - so then you accelerate, turn the injectors off and open the throttle body to full to reduce pumping losses............................then turn on when needed.

I think this would be easier and safer, even if less efficent then a full pulse and glide.

Wow, I never thought of turning off the injectors and flooring it! I have just been mostly just pushing it into nuetral to coast in traffic and using the kill switch when I know I'm gonna sit at a light when I stop.