Hey everyone. I just got my first Hybrid last week and I have been reading a lot of the pulse and glide. I cam averaging about 50 mpg as of now. How are some of these people peaking their numbers? Any tips???

Thanks!

 

Welcome to the club!

You might start with the Prius FAQ. This has a lot of lesson's learned including maintenance and driving tips. I prefer to maintain a steady, safe, low speed when driving but have no problem with coasting to a stop.

It is also a good idea to start recording your mileage in the database. This will let you track your progress. GOOD LUCK!

Bob Wilson

 

Right now I am averaging 56 mpg in my 2007 prius that I got a month ago. I have been using pulse and glide exclusively and takes quite a bit of getting used to. I live in a fairly hilly area so I usually get great numbers going down the hills (have had trips at 90 mpg) and worse numbers on the way back up!

 

Thanks for the assistance. Currently, I have been using Pulse and Glide (as good as I can) and I am averaging about 52 mpg over the past 150 miles. I do not quite understand, however, what is the best way to get to the pulse speed. I saw the diagrams but when I try to do so, I hardly accelerate. Am I just in need of more practice, or does it seem like I am missing something. If anyone is from the Southeast and wants to teach me how to drive this thing properly, that'd be great. HAHA!

I think the biggest problem I have currently is when I am driving about 55 mph. Any suggestions--I can't quite understand Warp Stealth so . . . Thanks again everyone. This site is amazing!

 

That is a pretty large area. How about state and city?

If you have the time, you might go to Hybridfest. You'll find a lot of folks there willing to cover the subject.

Bob Wilson

 

Northwest Florida to be more precise. I am doing much better with the techniques I have learned, but I am in no sense a hypermiler yet . . . sadly, because I do try! I've learned which route is better for gas mileage and such, but I still cannot fathom some of the stats and pictures I have seen of people having 100+ segments. There ahs to be a secret out there somewhere!

 

Hi,
First let's go over the maintenance checklist:

• oil level 3/4 full mark?
• tire pressure 42/40 or max sidewall?
• recording mileage in database?
• warm-up segment 1-2 miles of 25 mph or less?
• cool-off segment 1-2 miles of 30 mph or less?
• max speed 65 mph or less?
• Staying out of the 39-44 mph range?

Realize the MPG is a function of speed:


See if there is an industrial park or large shopping center where you can set your cruise control for 24 mph. Ideally, it should be fairly flat, somewhat wind protected (aka., trees), and have no stops. For good measure, warm-up the engine and systems by traveling at ~55-65 mph for 10-15 minutes before entering your 'test track.'

Once you reach the test area, set the speed for 24 mph and reset your MFD. Drive for 30 minutes and report the MFD mileage. The cruise control can hold 23 mph but if there is any small rise, it can 'kick out' when the speed drops below 22 mph. I find 24 mph is a better target speed but experiment.

Now if you want to do better, manually control your speed to hold 18 mph with a range from 16-21 mph. But try to keep it at 18 mph. You should easily achieve 99.9 MPG. If you have a wind, keep on the 16-18 mph range into the wind but you can go 18-21 mph with a tail wind.

Bob Wilson

 

I have not tried a speed range that low but I may have to in the future. FWIW, I pulse up to 28 mph and glide back to 20-21 mph. I learned of this from VaBeachPrius. With this technique I have acheived a personal record of 152 mpg on a 7+ mile segment from my bank to backing into my garage. I will sometimes let my speed drop below my target range if I'm cresting a hill that has a downhill that is big enough to get me back into my desired range. Otherwise I will try to at least be at the top of my range when I get to the bottom of the hill. When pulsing back up to 28 mph, I try to keep my rpm's as close to 2K as possible and try to never go above 2200 rpm's per Hobbit's research on acceleration in a Prius. This acceleration rate will show an instant mpg on the FCD of 20-22 mpg. Also, if the battery is high enough, I will extend the glide at 20-21 mph by using battery. I try to start with 5-6 bars and like to have 3-4 bars by the time I get to my driveway which is ~.1 miles long with a 1-2% uphill grade.

Warp stealth, if I understand correctly, is when you are over the 41 mph glide threshold and you let off the pedal and get into EV(yellow arrows only) as you are gliding down to a lower speed. I try to use this technique whenever I can on roads with higher speed limits/traffic.

 

Just a couple of questions:

• What is your round trip best?
• How did you measure 152 mpg?

A round trip makes sure other sources of energy such as potential energy are not involved and the battery can be good for a mile. As a general rule, the first mile should be dropped to normalize the battery state of charge.

Were you using one of Ken's super scanners? Normally, the MFD pegs at 99.9 MPG.

As a suggestion, you might try a circular route using both your 20-28 P&G as well as the equivalent, steady speed. I've been doing some work in this area:



The first set of charts were used to measure the equivalent steady-state speed. It was also used to make sure the protocol was reproducible. One of the classic problems with most P&G protocols are imprecise instructions. In this case, the glide uses "N", a completely energy neutral glide. The pulse used cruise control "resume speed," which ensures a reproducible acceleration.




The above set of charts show the results of 25-43 PnG. The data suggests PnG is about 11% more efficient than the equivalent steady-state speed. However, this is also the maximum, speed difference possible using cruise control and staying in the ICE-off, "N" glide range.

The following charts show the data used for the above summary chart:




The following is an interesting chart from manually trying to stay at 18 mph. What is curious is the ICE failed to cycle off, initially. This could have been S-3 mode. Later, the normal ICE on/off cycling resumed. Regardless, the energy consumed was pretty good, 255 J/m.


So I tried using PnG that gave the same block speed, 18 mph, and found the energy consumed was higher, 299 J/m versus 255 J/m. Steady-state required 17% less energy than the equivalent PnG.

Near as I can tell, the optimum distance speed is ~18 mph within a speed range of 16-21 mph. So far, my limited attempts to PnG around this speed have consumed more energy than the steady-speed mode.

So why is this important?

It looks like my Prius gets about 15,000 J/gram of ICE shaft energy and it takes 255 J to move one meter. One gram of gas should move my NHW11, 2003 Prius about 58.8 meters. With ~2,659 grams/gallon and 11.9 gallons per Prius tank, one tank should give 1,860,555 meters or about 1,162 miles. This isn't bad but I would prefer more margin.

Bob Wilson

 

On the trip where I got the 152 mpg segment, I averaged 119.5 for the round trip. I was using a Scanguage 2 to measure it. At last check, the SG seems to be slightly low when compared to the car's FCD screen. It may take another tank ot 2 to get it dialed in closer.