Few Questions

I assume you're referring to the electric motor. Minor terminology issue, but the term "engine" -- in these parts, anyway -- refers to the internal combustion engine, or ICE as it's commonly abbreviated.

This might be a large part of the problem. It might seem counterintuitive, but you're better off not trying to run with the motor. I'll spare you the details for now (you can search around a little if you want to learn more), but running off the battery is inefficient. Its purpose is not sustained propulsion, but rather short bursts of immediate power for rapid acceleration. Meanwhile the relatively small ICE burns less fuel during steady-state driving than a larger engine that you might normally find in a 3000# car.

Try just driving it normally for now. That's presumably what you were doing on that first drive, the results for which are very respectable. It doesn't take any special technique to achieve good results.

If you want more than that, hang around here, study up on the various fuel economy threads, and learn some of the advanced techniques -- "pulse and glide" among them. And be persistent in practice and patient with results.

 

The gas gauge is nonlinear, and, because of the internal bladder, the fuel tank capacity is both variable and usually less than 11.9 gallons. There is no way to know how much fuel is still available in the tank when the last pip starts to flash, so if it gets that low you must buy gas immediately (as you did).

It may seem like a paradox but to maximize MPGs you want to use the battery as little as is necessary. See discussion at http://priuschat.com/forums/fuel-economy/44642-pulse-glide-accelerate-fast-slow.html

 

Lots of issues.

The flexible bladder in the gas tank means that you're likely to fill to differing levels each time, so a manual calculation of mileage must be averaged over numerous tanks. No one-tank calculation is reliable.

DO NOT try to make the car run on electric. It was not designed to run on electric and there are very few situations when running on electric is efficient. The car was designed to combine the gas engine and the electric components in a way that they work together. That's what hybrid means. For best mileage follow the same rules as for any car: avoid jackrabbit starts and quick stops. Drive safely, moderately, gently. Do not baby it, but do not race it.

Yes, temperature makes a big difference. Also very short trips will give poor mileage.

Basically, just drive it as you'd drive any ordinary car. Very few people get the EPA mileage because the EPA test is not realistic. Mid-40's for mpg is normal. It will get better in summer.

Enjoy the car.

 

Have you read the sticky about improving fuel economy? What is your tire pressure? For better economy increase to at least 42/40. Read the threads about grill blocking. Run the climate control manually. Temp set at 73F, fan speed low will not stress the fe when the grill is blocked and gives enough heat (at least down here).

 

73F JimN??!!! That's way to warm ... put on an extra layer and turned it all the way down .. or at least to 67F - that's what I had it on all winter. Happy motoring
Gabe

 

I'm not having a go at the OP because a lot of people seems to do this with the fuel.
Why are people so fascinated with not getting 11 gallons of petrol into a Prius? If the gauge is on 2 bars fill it, if it has 10 bars it's full or nearly full. When the pump clicks off round off if you like but if it clicks off a second time at slow fill it's full.
Your friendly handbook says it is a good idea to maintain at lease a quarter of a tank of fuel at all times, if however the last bar flashes fill up immediately. It isn't rocket science.

To get the best mileage try to drive not using the battery but just on the petrol engine. Trust me on this, all the power comes from the petrol engine anyway.

Read all the tech threads on PC.

Enjoy you new interactive driving game.

 

The previous posters have it right. I want to reinforce two points, or three if you count the advice to read some of the information available on other threads. Here are the two things you need to know:

1) Avoid trying to drive on electric. Just drive the Prius like a normal car and let it take care of the details.

2) The fuel tank holds a variable amount of fuel. You never really know how much it has left, so you can't do any meaningful manual calculations. Don't bother; you will only end up frustrated and confused. The only way manual mileage calculation can be useful is doing it over a LARGE number of tanks.

That's it. Don't worry about the lower mileage; it's probably just cold weather and forcing electric mode. Enjoy your driving, and welcome to PriusChat.

Tom

 

Hello,

I'm the new owner of a used 2004 Prius that I bought a few days ago. On my first tank, the computer reported that I averaged 50.8 mpg. At the gas station, I filled 9.96 gallons, and the trip odometer read 440 miles.

If I'm reading this thread correctly, I am NOT getting 44 mpg (my manual calculation)? Then did I get 50.8 mpg on that first tank? I guess my question is, how many mpg did I get exactly?

Many thanks in advance for clearing up my confusion!

 

Based on the experience of many here who have tracked calculated MPG over many tanks (including me), 50.8 likely is closer to the real MPG than 44. In my case, for the last six months, the average displayed mileage is 1.2% higher than calculated. Others have reported greater variations, in the range of 2-4%, IIRC, all showing the display to be a bit optimistic. So if you're anal retentive like me, track it over several tanks. If not, be confident the display is pretty close.

 

You're on target there, assuming you're referring to a slight steady pressure rather than a repeated motion. ("Tapping" to me means a repetitive thing.) This is the glide part of "pulse and glide" that I referred to earlier. When decelerating, let off the gas pedal completely to allow the ICE to cut off (it will do so only after it has gone through its warmup stages), then immediately feather it back down just enough to make all arrows disappear on the Energy display. (It works only at 40 MPH and below.) Hold it steady until you need to slow more quickly or get back on the gas. This is roughly the equivalent of coasting in neutral in a conventional car with the ICE off (but without the loss of go-pedal control), and makes best use of available kinetic energy.

In the same way efficiency is helped by avoiding battery use, it also is helped by avoiding unnecessary charging. Better is to let that kinetic energy go to work for you immediately instead of channeling it back into the battery.

 

73° to me will make me sweat driving. I set my temp. at 68° in the winter. This summer, I will have to experiment what temp is best. I'll probably start at the 70° mark.

 

Great, thanks! I'll just have to remember to update my excel sheet in the next few months!

 

not that it's a surprise to most people on this forum, but that pulse/glide stuff really works! i'm not even close to perfecting it, but i've seen a substantial improvement (driving the same routes) between my first and second tank on my new used '04.

First tank:
display mpg: 50.8
calculated: 44.0

Second tank:
display mpg: 57.6
calculated: 56.5

thanks for all the tips!

 

Some of us have thin blood however next winter I'll try lowering the temp. 70F in summer sounds way too cold. I would think matching the OAT or high 70's would be in order. During the Indiana trip last August I seem to remember that it was set at 79 or 80. I was fine but my friend complained later that it was "stuffy".

 

one thing i didn't see mentioned, make sure the transmission is in "D" and not in "B".