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

[JimboK]

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

I am getting ready for a trip down to LA and wanted to know exactly how my speed will affect my mpg.[/b]

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.

[bwilson4web]

Hi,

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

[Prius 07]

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

I am so embarrased. I just saw the "post you beat the EPA mpg threads".

Wow! Those numbers are incredible.
[/b]

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

[ScottY]

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

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

[sounds_great]

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

Procter & Gamble

But in this case, Pulse and Glide.
[/b]

LOL!!!!!!!

[Rangerdavid]

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 !!

[JimboK]

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

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

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.

[JimN]

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

I just did a tank where I averaged 50mpg. Display read 50.7 and calculated it came out to 50.1. In the past I have been getting about 45mpg. I know that is not a fantastic number, but I am still excited about it.

I do a 50mile round trip commute from Danville/San Ramon to downtown Oakland. Mostly freeway and the traffic is not too bad. I got the better mileage mostly from anticipating a bit better and reducing my top speed a bit. I don't really have a set top speed, just try to take it easy.

I am 110 miles into my next tank and the average is at 55.6, maybe I can keep it up? I would be ecstatic with a 55mpg tank.
[/b]

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.

[Orcatek]

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.