Few Questions

[wayupnorth]

Hey All,

I bought a new Prius in December of 2007. Not really sure what package it is, all I know it was the middle out of 3 packages my dealer had. No blue tooth or GPS but seems to have everthing else. How do I check? It is a green 2008. I know that much! ha ha

Here are my questions. When I first took it home (about a 68 mile drive) i was getting 47 MPG. Now I am only getting about 32.2 around town so the computer tells me.

I decided to do the math myself. I went to Kingston NY from almost canada where I live in Vermont. The way down was 352 miles by the time I filled her back up. It took 7.48 gallons of gas. If you do the math that is 47.6 MPG. The computer told me I was getting about 31.

On the way back I took a longer route 365 miles. By the time I pulled of the highway in my hometown the car informed me to "add fuel". I did. 8.8 gallons. With a 11.9 gallon tank I still had a few gallons left to play with. Is that normal. This worked out to 41.3 MPH.

Next test. My job is on the road and I make several 1 to 2 mile trips. My next fill up driving around town and my normal day was 192 miles using 7.5 gallons of gas giving me a mpg of only 25.6!

Granted where I live is cold and the car has not seen weather of over 45 degrees yet. Except in NY where it seemed to do better. Is this normal?

There are not many prius owners in my town but the few I have talked to are getting way better! (have also owned theirs for over a year) I have about 3200 miles on it now.

Is this just a breaking in period? Temp issue?

I have been very careful to drive slow and use the electric enging as much as possible but it dosn't seem to be working very well.

Also still wondering why my inital trip was getting so much better mileage than when i bought it. Have made that trip a few more times but with much less impressive results.

Any tips or comments will be greatly appreciated.
Thanks,

wayupnoth

[JimboK]

Originally Posted by wayupnorth

I have been very careful to drive slow and use the electric enging as much as possible but it dosn't seem to be working very well.

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.

[richard schumacher]

With a 11.9 gallon tank I still had a few gallons left to play with. [...]
I have been very careful to drive slow and use the electric engine as much as possible but it doesn't seem to be working very well.

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 pulse & glide... accelerate fast or slow?

[daniel]

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.

[JimN]

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).

[Prius 07]

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

[patsparks]

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.

[qbee42]

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

[hoodenc]

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!

[JimboK]

Originally Posted by hoodenc

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.