How to achieve 100 MPG
 

Hi folks,

I've published a web page about how to achieve 100 MPG with my NHW11 model Prius:

http://hiwaay.net/~bzwilson/prius/pri_test.html

I've posted this to help folks achieve at least 100 MPG over any given distance or fuel consumption. If you have the time, follow the receipt and 'get over it.'

The real challenge is to find ways to maximize Prius performance in ordinary driving. I want to drive just paying attention to traffic and automate or build-in vehicle efficiency. Success is when my non-technical wife achieves hypermiler performance. But it is also when these techniques are shared and adopted by those who want to achieve similar performance.

Bob Wilson

Re: How to achieve 100 MPG
 

In layman's terms, the point is to slow down. Driving slowly and accelerating slowly (without blocking traffic) is a great way for the individual to anticipate traffic, traffic signals, and to be left alone (mostly) by other cars (they will pass).

It is one thing to get 70 mpg on a closed portion of roadway and another to get the same or higher with traffic and lights. Conciously picking roads with slow speed limits can yield values close to 100 mpg. It would for me to just set the cruise control and just go. That is where pulse and glide tied into anticipation of traffic yields excellent results in everyday driving.

See my best segment below.

Keep up the good work.

Re: How to achieve 100 MPG
 

More precisely, the speed and vehicle drag ultimately dictates how much energy is needed to move over any given distance. The trick is avoiding inefficiencies, energy losses, while maximizing ICE efficiency.

Exactly, the primary determinant is speed. Clever route planning where the low-speed segments are also short-cuts, leads to excellent MPG without a commute time penalty.

Someday we must perform the following experiment:

1. Drive a fixed route using "pulse and glide"
2. Drive the same route using constant speed

Fortunately, it is easy to modify the described protocol to accomplish that end.

I have a graduated cylinder coming that with a fuel pump, filter and some piping will allow precise measurement of vehicle fuel efficiency over reasonable intervals. Then it will be easy to perform a well defined, 'pulse and glide' benchmark followed by a constant speed test using the average speed of the 'pulse and glide'.

So the only question remaining is what pulse and glide protocol should be used for an average speed of say, ~15 mph?

• 20-10 mph
• 25-5 mph
• 30-0 mph

This is just a math problem.

Bob Wilson

Re: How to achieve 100 MPG
 

I would certainly love to just set the cruise control and go to work. I would be fine with it set to 25 mph. However, on my route to work, the speed limits are between 25 and 45 mph. I seem to do the best P&Ging between 19 and 28 mph; with a little EV here and there; traffic dependent.

When it warms, I still owe you information on cruise control steady speed conditions. I set the CC at 24 mph last fall and saw three bars at 80+ mpg.

Re: How to achieve 100 MPG
 

When you get a chance, what is the distance and time?

With my NHW11, that should give a maximum performance of a little over 90 MPG. That is well within the capabilities of my test tracks. Now with my temperature hack and moderate Alabama temperatures, I can easily repeat the experiment. My first attempt, without the thermistor hack, gave ~68 MPG on the 60 ft., 0.9 mile track in 45F.

Preliminary data with the temperature hack suggests the NHW11, 01-03 Prius, will see a substantial performance improvement at low speeds and on commute routes. This is without P&G.

Bob Wilson