Hypermiling

Driving coach helps alot. I use pure gas and inflate my tires at 42 psi.

#1 in Easley,SC

 

For efficient driving:

• fully inflate the tires
• drive as slowly as traffic allows by following semi-trailer trucks, delivery and service trucks, and pickups towing a trailer
• anticipate stops by slowing down early and try to reach a stop light when it changes

Bob Wilson

ps. Qualifications, 2010 Prius, July 21, 2013:


Took just under three weeks while working; driven solo; minimum one hour duration per trip; cruise control set 26 mph, and; shift to "N" on down grades.

 

With fuel prices so low, these threads simply haven't had much activity and are no longer anywhere near the top.

 

It means you are driving so slow that people behind you get annoyed.
I know because I used to be the one getting annoyed, now the shoe is on the other foot.

 

That is why you follow large trucks to camouflage what you're doing. Following traffic passes the truck and does not tailgate the Prius until they can pass.

Bob Wilson

 

Three rules:
Drive safely
Drive courteously
Drive economically

Inflating the tires above the cold inflation pressures shown on the placard on the car will reduce traction. The limit of traction will be lower. People who have done this with no problem have been fortunate to not need the maximum limit of traction of their tires. Don't inflate above the max pressure shown on the tire sidewall. (I know some have run at increased pressure, and at their own risk.) Higher pressure causes a shorter contact patch of the tire on the pavement--less traction. It also has less flex in the tire for reduced rolling resistance--saves a bit of gas--and reduced heat in the tire--adds to tire life. Everything is a compromise.

Depending on the shape of the car, running at speed with open windows can have a lot of drag and be less efficient than running with windows closed and AC on.

 

Yeah I do try to stay in slow lanes of traffic.

 

i can do the pulse and glide pretty well, without bothering too many people. it's going the speed limit that drive's people batty.

 

my name is Tom and I'm a hypermiler, not a fanatical one. I've been doing if for about 11 years starting with a 99 Solara then a 2012 v. I've used a lot of the techniques mentioned here. I over inflate tires, drive fairly slowly (trying to be considerate of other drivers) and a host of other things. 1 thing I used to do was pulse and glide, even on slight declines, but that isn't too efficient in the Prime. For the Prime on slight declines I use the HV portion of the battery to pick up speed and get farther up the incline without the ICE coming on. I've never been able to use HV battery over 43 mph, but with the Prime I use it a lot at any speed. My commute is 72 miles round trip and the last 2 days I got 155.1 and 158.8 mpg on 1 charge each day. Mind=Blown. Never thought that would be possible. Loving the Prime. Prime On!

 

Tom, I ran a benchmark testing pulse-and-glide vs the equivalent constant speed using our BMW i3-REx and found no measurable difference. Speculation on my part but improved control laws and deep EV especially in the Prime makes pulse-and-glide ineffective.

Bob Wilson

 

shouldn't the motor have an efficiency curve which would relate to a most efficient mph? (not that you can drive one speed all the time)

 

I agree that it is not efficient for the Prime. I've never done any testing but I'm glad you have and shown that is ineffective.

 

Compared to an engine, hardly any and actually inverse of a throttle engine. Engines are inefficient at partial loads and really become efficient at higher power. Electric motor inefficiencies are more rpm related and the efficiency changes much smaller than an engine.

Bob Wilson

 

Puse-and-glide is only meaningful when in HV mode, where all the energy is ultimately coming from the ICE. Pulse-and glide is an attempt to have the ICE always running in its most efficient conditions. The "pulse" is designed to load the ICE and put it into its efficient range. Part of the energy goes into the battery. The "glide" then uses the electric motors for a while. None of that is particularly meaningful when using just the electric motors.

 

I'm not *quite* sure I think of that as a "key", but I do know this: Whenever I'm hypermiling, I find myself glancing in the rear-view mirror/s about 5x as often as when I'm NOT trying to maximize efficiency...

 

and smiling?

 

FIRST of all: "Hello, Tom."
SECOND of all: Those are some AWESOME (MPGe) numbers!