Why are MPG's all over the place?

To follow up with another thought...

The Prius definitely trains you to drive better, and some people will learn and some won't. It gives you much more feedback about what's going on, and more tools to work with.

At the same time, the EPA test isn't designed around hybrid driving techniques, so it's not simply a matter of some people learning to drive the Prius "properly" and some people not learning. It's a scripted test and the Prius gets 50 MPG combined MPG. YMMV.

The EPA test can't account for weather (temperature and precipitation), terrain, horrible traffic patterns, and last but not least, driver habits. But it certainly also does not account for the fact that it's a hybrid, either.

 

I got about 38 mpg on the first tank. Got about 44+ on the 2nd tank and was starting to feel a little better. With close to 1k miles on the car, the avg is now up ~41.5 mpg. My brother has a Gen 2 and says he NEVER got less than high 40s - I was bummed. But then I decided that 4 mpg x 11 gallons wasn't that big a deal. Plus, I think the car deserves a break-in period.

For me, maintaining good mileage is a battle - especially when leaving the stop lights. There's just no way, short of pissing off the people behind me, to get off the light w/o getting into the Pwr range in the slider.

 

How can you tell what MPG you have gotten since you bought the car? Any way to do that electronically or do you have to keep track of it yourself?

 

ALL autos suffer poor mileage during their warmup. It's not a hybrid issue. If you have a very short commute, you will get poor mileage with any vehicle ..... short of an all electric.

... Brad

 

1. What are you driving now?
2. What is your current MPG's?
3. What is your "typical" commute (e.g. 20 miles, mostly freeway, speeds of 70 - 75 mph? 3 Miles to school and then 4 miles to work, all city driving).

#1 and #2 are for comparison sake to EPA. #3 will be critical to what you can expect in your real world MPG's.

People who get low MPG's typically have anyone of the following hinderances (very short trips/commutes (5 minutes or less), live in very hot or very cold areas (A/C or Heat...both make the engine run more), very hilly areas where you can't maximize your battery regeneration (e.g. ending one's commute on a steep grade).

There is a thread called "you won't get 50 mpg if....". Check it out, it covers many of these items.

 

When I read up on the Prius before buying, the group getting the worst gas mileage with the Prius were none-the-less ecstatic with their mileage.

Rural postal carriers spend their time merging then braking, mail box to mail box. This does not yield high mileage, (all that regen is losing mileage to heat) yet compared to vehicles not doing regen, it is phenomenal mileage. (35 MPG versus 10 MPG sure sounds good, even though 35 MPG in a Prius sounds horrible)

Another group of owners (me included) just drive normally as they did before they got a hybrid, assuming they have a long commute, 40 to 48 MPG are typical.

True hybrid gurus get more than 50 MPG (this is easier in Gen III than in my Gen II) using Pulse and Glide, feathering, and memorization of every traffic signal timer in a 50 mile radius.

At some point they start modifying the hardware, oil, tires, EV switches, more batteries, etc.

35 MPG to 65 MPG - Sure, depends on YOUR style and commitment level.

 

Exactly like my wife. I have suggested a qualifying term for the gas mileage averaged by people like my wife, and most of the time myself as well:

WORT (WithOut Really Trying) as in: 50mpg WORT.
I hope it catches on...

 

I zero out one of the trip odometers each time I tank up, and leave the one other alone so its collecting cumulative data.

 

I have been averaging a consistant 50mpg by calculator and 54-56mpg by the computer. It does frustrate me that the computer is 10% off. I have calculated six tank fulls so far.

 

Good thread. I fall into my first tank, first hybrid and some what disappointed by me current MPG. I am up to 44.6. I have a pip less than half of a tank. Things that I have noticed.
My 1min/5min chart is very informative but always pays a prices getting on the highway. In fact if I have enough of these acceleration periods, my 44.x will go down. I got up .3 points this morning since I took the highway(5miles) to the back roads followed by 3 miles of interstate. This caused me 2 acceleration opportunities. I have to put in the POWER zone to get up to speed or frankly I WILL get run over.

I have tried driving very conservative(with in reason) the last couple of days on my 50 mile round trip. I wanted to take the back roads today to stay on roads less than 50mph so I could try pulsing and gliding. The gliding is pretty straight forward as you can see the MPH meter peg a 100 when you get it right for a period up until the ICE(scary - I am figuring out the lingo) comes on. Pulsing seems like slow burn of thrusters to pick up speed and the glide back down and repeat. I can tell you I can't see my self doing this in day to day traffic. I am more aware of gliding to a red light and using less brakes when at all possible. This makes serious sense and is easy todo.

But with all this, it seems that my MPG should be coming up faster but all it takes is the accelerations to wipe out my progress.

I live in a flat gulf coast region. It is hot and humid so the A/C is on all the time(although this car can really cool quickly). I haven't checked the tire pressures yet. I suspect I get an extra couple of MPG's out of that.

From what I have been reading I should be able to get 50 without trying so hard. I am not "dogging" the car by no means. Perhaps as I get my second tank in it and I will have a trip to Houston on Monday, this may tell me alot about my capabilities.

For now, I will keep reading and hoping.

--Mickey

 

i'm currently getting between 35 and 45. i have a poor 12v battery. (i jump start my car all the time.. with my jump-pack.) i have a sub... agressive driver. my tires are on my signature and they are in the 30psi range for comfort. they are also really heavy. i carry around tools, so.. extra weight. i have a tow hitch, which i'm sure increases drag.. shrug.. there are a lot of things.

if i'm towing, i get less than 30....

 

I can get any Fuel Economy reading you want from 25 mpg to 75 mpg....as long as you leave the driving to me. Seriously.

However if I drove the vehicle from NYC to LA in a manner 'normal' for me then I'd get 48-50 in good weather and 43-45 in bad weather.

2005 Gen 2 with 126,000 miles on the clock.

 

If you keep the HSI pegged in the PWR zone, you'll see your mileage drop like a rock. If that's what's required to get up to speed for you, and you have to do that a lot, I'd say you'll have to settle for the consolation prize of knowing that you're still getting way better mileage than if you were doing the same thing in a non-Prius.

(Also, your mileage should get better over the first 1,000-2,000 miles. And you'll get better, too.)

What do you set your A/C at? If you're setting it at 72 or something you might set your house to, try setting it to 78 instead (recirculate on) and adjust vents to the moment (on you, past you, away from you). And check the tires: I like 40/38, which isn't too hardcore.

You do get a feel for things over time, too. Watch the HSI bar. Watch the instantaneous MPG indicator. Watch for opportunities to coast, or better yet glide.

Good luck!

 

I have read the above post and there has been good advice. I own a G3, IV with 2350 miles. My "lifetime average" is 53.5mpg. I have not changed the tire pressure; I drive pretty much normal. Someone on another thread, mentioned driving in Houston, and getting terrible mileage. I do not wonder ... Houston is terrible place to drive ... everyone drives over the speed limit; hard acceleration from light to light; slamming on the brakes when others cut in front; and heavy A/C use.

Incidentially, I have never gotten lower than 50 mpg. That is the EPA estimate, and anything better than that is great. You will read about "hypermilers" getting really great mileage, but it is not worth the hassle to me.

I have been most impressed with the mileage, comfort, fit and finish, and interior room. No squeeks or rattles either. The only thing I am going to do is raise the aim of the headlights. A bit too low for me. Good luck.

 

I do find that when accelerating to the right of the ECO, I can see the MPG drop to 4-3 bars and lower as approach PWR. Once I am in PWR, I have 3-2 bars. I then depends how long I burn to come up to operating speed as to how the Minute of consumption will be displayed. I see usually a 25 mpg bar when this occurs. I do notice things line out nicely when I get to speed.

Looking forward to that.

72 is perhaps what is set getting into the car at 95+ outside for short period to cool down the car. Icecycles will begin to form on various parts of my body if I leave it there too long. So I ma back up to 75-77. Leaving on 78 in the mornings cause the heat to come on - why I don't know. Its 75-78 outside in the mornings here. Auto A/C causes me to use it before I walk outside.

All in all - I feel much better as I was able to bring my MPG up to 45.7 before filling up. I had 2 bars left and only took 8.2 gallons. Says I have a lot left in the tank. Good to know. Came home driving a conservative normal - Mainly all highway. New average is 52.7 at 10 miles. Yeah ME!!!! I think I had a bad start to my ride when I picked up. Who knows why. I know now that 50 is obtainable with good driving practices. Now it is up to me to drive how I want my mileage to be. Perhaps my curiousity will allow me to try power mode to see how bad it can get. I like to know my limits of each side of the spectrum.

Thanks for the encouragement.
--Mickey

 

100%, to a tee, ditto here.

I am anxious to see a 50, I am pretty sure it will happen.

 

When I first got mine I was on vacation, long drives. I averaged 51.3 Now that I'm back to work, shorter drives, I only average 46. Still twice what I was getting before.

 

Wow, you have larger temperature swings out there (or get up way earlier than I do). I think the rule of thumb I read was 2 degrees below outside temperature, but no higher than 78 degrees. So if it's 78 out, you could try 76... I always have it in manual control and am not really sure how AUTO works. (I want recirculate at all times for allergies, but also because it's WAY more efficient and comfortable, too.)

I've found that 78 (with recirculate on!) will keep me comfortable at least into the mid-90's that we've experienced occasionally this summer. If it's not quite enough, I point the vents at me, otherwise, I point them so they're shooting just past me. Also varying the fan speed from 100% to cool down, down to a couple of bars once it's comfortable.

EDIT: I'm not sure how much of a difference it makes to turn the temp way down for initial cooling. Theoretically, if it' 100 in the car and you have the thermostat set to 78, I assume it has to go full-out to try to hit 78 and setting it to -37 degrees won't cool it any faster. Or, in manual, does 78 mean it spews 78-degree air and it has to be in AUTO mode (perhaps) to treat 78 as a goal and not the current setting?

 

The first tank of gas is sort of whacky, in my limited experience. My car was only driven 3 miles before I got it, but it was a lot of very short trips, so the gas mileage I started out with was horrible (and I didn't think to reset my trip odometer right away). I was lucky that the tires were inflated to 40, but they could've been almost anything.

I drove based on my misconceptions of what was efficient, including trying to use the battery a lot. And I was too fixated on the HSI display without understanding that as the human I make the tradeoffs, perhaps getting poorer mileage now in order to get better mileage ahead.

Of course, we obsess on the first tank, because we want to see the super mileage the car gets and we have visions of getting more than that because we're smart... But of course we're just beginners and in a sense, so is the car.

For the first couple of tanks I was averaging about 50 MPG on my commute. At about 2,000 miles now (about 200 miles a week), I'm on a roll with an overall MPG of 55 on my commute. Some of it is me, some the break-in, etc.

 

I see the same thing here, heat sometimes comes on in the cool mornings when I leave it set to 78 or 80. I wish Toyota would design the system to have two different temperature settings one for heating the other for cooling. Like the one in my house has.