how to get best mpg

I've found that my MPG average increased by ~7 MPG (50.7 to 57) by cranking down the windows instead of using a/c and not using cruise control. I accelarate to the speed I want, then back-off to get into electric
motor mode. Nothing more.... nothing less. I haven't even fiddled with
the tire PSI. And don't think I drive like an old lady either.... I'm used to
high horsepower muscle-cars. That was one of my biggest fears when I test drove the car.... that it wouldn't have any "testicular fortitude." But I've pleasantly surprized ever since. :mrgreen: The car drives like a champ.

LT1bird

 

To get the best mileage the most important things are:

1 Drive slowly. Preferably at least 30 mph. Try never to be in creep mode, or going like 5 mph. Ideal may be 42! (so you get a choice of engine/battery and motor modes)
2 Try not to use brakes, and when you have to, brake lightly so you
can use regen.
3 Optimize the car: ie LRR tires, extra tire pressures, synthetic oil, no oil overfill. No roof racks. Light wheels.
4 Make all trips at least 30 minutes starting out, and then make short stops only if not done for the day. Every stop is costly but stops while cold are worse.
5 Warm up the car reasonably fast: ie avoid routes with 5 traffic lights right where you are trying to get car warm to stage 4.
6 Coast a lot. Possibly pulse drive when you can.
7 Try to not use cruise control, and learn to hold accelerator very steady.
This means slowing on hills, then coasting down them, to the extent possible.
8 Minimize use of AC and heater.
9 Add an EV button and learn to use it to max mileage.
10 Move to a good area to handle the above:

ie: a place that is flat or has hills you don't have to use brakes on.
a place that is always about 70 to 80 degrees, humid but not with rain.
a place that has not degraded the gasoline to sell corn or reduce ozone.
a place without traffic lights or at least synchronized ones.
a place with no other traffic than your car.

Now with just this you should be easily getting over 60 mpg. Then you are ready to worry about the little things like:

How to accelerate best:

Three schools of thought here I think:

1 control the arrows to minimize losses to/from battery. (This can be at various actual acceleration rates so can combine with other methods)
2 accelerate briskly which I think means use ideally about 70% power.
3 accelerate slowly. ie not much power beyond that needed for your final cruising speed.
4 Doesn't matter if you did item 10 since you won't need to accelerate often enough to notice any effects.

No need to rehash this here, so go read the stuff you want to avoid:

First read the knowledge base threads. Second read the mileage threads. Then search on "mileage" "arrows" EPA etc to find the rest.

To try to put numbers on the above: I'd say the top 10 items can easily cause mileage differences of 30 mpg or more. (Bulk is due to trip lengths and temperatures, plus cruising speeds.)

After that things like acceleration style, may get you more like 5 mpg more, unless you do it so often you'll be braking too and getting terrible mileage anyways.

When you read the mileage logs, try to relate your mileage to what others are getting with similar conditions. If you live in Alaska you won't get what someone in Texas can achieve. People in San Francisco probably won't do as well as those in New York City. etc. That way you can see if you're doing reasonably. Everyone wants to get 60 or more mpg, but very few do it, and most of them don't do it all the time because they want to travel at 70 or 80 on a trip etc once in a while.

Keep in mind that a Prius is affected much like other cars for mileage driving. But the things that are different you need to understand a bit.
These are:

1 It is a real Hybrid. Can run on engine or motor or both. Let the car pick the right combo till you learn enough to help it decide better! You normally know some things the computer can't like how much hurry you are in, traffic conditions, and terrain or stops required ahead.

2 It is a low pollution car. This means it has to warm up good before it works in an economical way. Learn the stages of warm up.

3 It is efficient enough that keeping it warm for item 2 can be a problem in cold weather.

4 It can be set to coast by proper accelerator position without having to use neutral. Other cars must go to neutral or with manual shift you can put in the clutch.

5 Engine can shut off at lights. But not always. So avoid those conditions where possible.

6 It is an Atkinson cycle. This makes it less lossy than other cars when you accelerate briskly.

7 It can be possibly extra sensitive to fuel quality.

8 It has stages of warm up where it does different things, and you have to optimize differently while in each stage, or to get to the next one.

9 It can go a mile or so if not uphill in EV mode, maybe avoiding a whole warm up cycle. If you have the button.

10 Computer tends to keep thinking you want do do more of what you were doing till you tell it different. Thus after accelerating it helps the rpm slow and economy get better if you feather, etc.

 

Tom,

That was a well thought out and nicely organized description. (I'm a professor and can be damned picky too)

Thank you very much for a good explanation.

Terry