I'm not a hypermiler, but....

<div class='quotetop'>QUOTE(Winston @ Aug 15 2007, 06:20 PM) [snapback]496436[/snapback]</div>

You shouldn't be embarrassed about getting 50+ MPG, especially during a commute. I have a 72 mile (RT) commute in mostly heavy traffic, and I'm getting just over 50. On the weekends, when I have a 120 mi. round trip to my boat, mostly on rural roads where I have little traffic to deal with, I get around 60 MPG.

I know it's possible for me to get even better mileage, though I also like to enjoy the drive, and try my best to be courteous to the other drivers by accelerating at a moderate rate. I rarely P&G (usually just on hills), and would rather just set the cruise at the speed limit. I try to anticipate slowdowns, and get on the brake quickly (but gently) to maximize regen at traffic lights and such. I also keep the AC at around 77°. I could set it higher and get another mpg or two, but I also want to be comfortable. I find that with my Prius, my entire driving experience is better, since in my other cars I usually drove as fast as I thought I could without getting a ticket.

I'm not knocking the high-milers-- they probably get just as much pleasure getting the incredible mileage that they do as I get driving the way I do. And even at 50+ MPG, while it may seem low when you compare it to other hypermilers, I'm sure your friends and neighbors turn green with envy if you tell them the mileage you're getting. B)

 

I just discovered a sweet spot today, if you are on the highway and drive between 52 - 54 MPH you can average over 60 MPG with no tricks. Easy to do in slower speed limits through the city. I just happened to have my cruise set at 53 MPH and just noticed that the energy screen constantly read between 58 - 85 for a full 10 minutes. I tried it on my way home same highway which is mostly flat and had the exact same results. (outside temp 78 degrees)

 

<div class='quotetop'>QUOTE(GeoDosch @ Aug 15 2007, 03:44 PM) [snapback]496444[/snapback]</div>

what does ''P&G" mean?

d

 

<div class='quotetop'>QUOTE(sfdafna @ Aug 16 2007, 11:29 PM) [snapback]497675[/snapback]</div>

Procter & Gamble

But in this case, Pulse and Glide.

 

<div class='quotetop'>QUOTE(sfdafna @ Aug 17 2007, 02:29 AM) [snapback]497675[/snapback]</div>

If I understand it correctly (and I don't profess to understand all of it), "P&G" means Pulse and Glide --- a method of driving the Prius to maximize gas milege. First you briskly accelerate to a certain speed. Then you let go of the accelerator. Then you lightly step on the accelerator to zero out the consumption arrows on your screen. Then you wait until the speed drops to a level acceptable to you. Then you start the whole Pulse and Glide cycle again.

One thing I always worried about P&G --- isn't that a distraction to safe driving habits? Or for those who practise and master it, does it become undangerous second nature?

 

Once you become comfortable with P&G you can pretty much do it without looking at the MFD. You know the feel of glide and you can tell when ICE kicks in.

As for the 50MPG tank, congrats! Given that you are driving mostly high speeds in CA I think that's a notable achievement. Keep working at it and let us know if you can pull 55MPG

 

<div class='quotetop'>QUOTE(morpheusx @ Aug 17 2007, 02:45 PM) [snapback]497658[/snapback]</div>

Please be aware that there is no such single sweet spot at highway speed, but slower is better down to 20 mph.
(maybe, the sweet spot is 20 mph)
Please refer to the Wayne's chart.
http://priuschat.com/index.php?showtopic=15285&st=32

Ken@Japan

 

<div class='quotetop'>QUOTE(Winston @ Aug 17 2007, 02:21 PM) [snapback]497935[/snapback]</div>

If you're interested, you can know how speed and many other variables affect MPG using Wayne's simulator for yourself. It's available for purchase for either Windows or Palm OS.

 

I have great respect for Wayne's work and feel you won't go wrong with his simulator. I would recommend his latest version.

My approach to the same problem has been based upon a series of benchmarks either I've done or others have done. Then about a year ago, Ken@Japan pointed to a Toyota reported drag formula. This graph shows my best understanding of NHW11, 2001-03 Prius performance with some NHW20 data points:



This has already resulted in a 'thermistor hack' that solves a great deal of the cold weather driving problem. Other folks have gotten similar if somewhat limited results using block heaters.

My current efforts are aimed at understanding ICE efficiency and mapping that back to the variable loads found in driving:



This effort is aimed at mapping high speed performance to map out the knee in the curve. With my vehicle, 65 mph is the highest 'sweet spot' that hits the knee at 70 mph. Speeds above 70 mph are the pits in an unmodified vehicle.

My plan is to look at this speed range, 65-75 mph, and see what various modifications might achieve. These range from drag reduction to power plant modifications. As I get results, I will be sharing but for now, understand that this is one of two 'bleeding edge' areas of investigation.

Bob Wilson

 

<div class='quotetop'>QUOTE(Winston @ Aug 15 2007, 06:20 PM) [snapback]496436[/snapback]</div>

50 is very good MPG especially in hilly SF - congrats Winston!

 

<div class='quotetop'>QUOTE(ken1784 @ Aug 17 2007, 12:42 PM) [snapback]497886[/snapback]</div>

According to hobbit, there is one.... http://www.techno-fandom.org/~hobbit/cars/sweet/

 

<div class='quotetop'>QUOTE(Bill Merchant @ Aug 17 2007, 12:35 AM) [snapback]497680[/snapback]</div>

LOL!!!!!!!

 

Congratulations Winston !!!! 50 is great !!

Looking at your info, looks like your car is an '07, so I don't know how many miles you have on it, if its broken in yet or not (usually around 5000 miles), or your experience level driving the car. Regardless, over time you car will break in, and your driving patters will improve and mileage will increase.

Just think about all your previous vehicles, and realize how really great 50 is !!

If you really want to increase your mileage, search the forums for "pulse and glide" and learn the techniques, especially at 40-41 mpg and under, and your mileage will skyrocket !!

 

<div class='quotetop'>QUOTE(ScottY @ Aug 17 2007, 05:37 PM) [snapback]498039[/snapback]</div>

I think Hobbit's message is not so much that there's a sweet spot for speed, but for RPM. That then helps maintain a somewhat efficient speed (or, at lower speeds, acceleration) range based on terrain and driving conditions.

 

<div class='quotetop'>QUOTE(Winston @ Aug 15 2007, 06:08 PM) [snapback]496429[/snapback]</div>

Good job, especially if your tp is under 42/40. The economy game isn't really a competition between you and another driver. The point is to improve the car (a little) and your driving (a lot) to get the best you can given your circumstances.

In a rally the conditions are the same so the game is between the two drivers.

 

I find that time I avoid the freeway and take the surface streets. With the freeway going 70 and the surface streets at 45, it only takes a few more minutes on a typical drive, yet I get much better MPG.