Something wrong with my Prius II - It takes more gas than it advertised.

[syncmacd]

Originally Posted by hschen

Thx, ksstathead.

My tires are new and at full pressure, I am sure.
I have been accelerating like granpa (too slow by any standard) in trying to stay in ECO mode. Too slow will decrease mpg? Then, someone please teach me how to drive for best mpg.

When I got my Prius from Dianne the tire pressures were set at 35. I bumped it up to the max (40) and no more my mileage jumped, from 53 to (current take pending) 60.

On the freeway I stay behind semi trailers, not to draft but because no one will get mad at me if I'm doing 65 mph behind a semi.

During the first few minutes I avoid pushing the car hard.

Finally, I avoid using battery power as much as possible. That's right, you heard me; I avoid using the battery power. Perhaps one of the hypermilers will correct me, but I find that accelerating the car under battery power to be much less efficient than using the ICE. The only time I willingly use up battery power is before my 2.5 mile downhill stretch that charges my battery close to full.

Battery power from brake regeneration is better than nothing at all, but it's even better not to put power into the battery if possible!

Finally, remember that this area (Southern California) is one of the harder areas to get good gas mileage because of all the hills. Going up and down hills is much harder on gas mileage than level ground.

Good luck getting your mileage up!

[bruceha_2000]

Welcome to PriusChat and the Prius

Originally Posted by hschen

Thank you, Zythryn.
I have a Prius Gen III Model II.
It's about 350 miles from Phoenix to Irvine.
Prius supposes to return better mpg in city than on freeway according to the advertised numbers - 51 city and 48 freeway. I just don't see that, yet, maybe, and hopefully ... and I am frustrated in not getting high mpg as I tried so hard so far.

Frankly, the fact that the car got 47.8 MPG doing 75 MPH for 4.5 hours instead of the EPA 48 MPG number should AMAZE you rather than frustrate you. Check the EPA tests before you compare your mileage to the EPA numbers. Highway doesn't mean Freeway, it means country road and it DOES NOT mean 75 MPH. The average speed on the 10 mile highway test is 48 MPH. Go to this site:
Fuel Economy Test Schedules and click on the 'detailed comparison' tab on the right. Also look at the graphs on the other tabs.

The only reason the car basically DID get the 'highway' number is because it is almost dead flat from Phoenix to Irvine. Take it up the Rockies at 75 MPH and you won't be looking at 48 MPG.

Second, as to the City mileage - "Your mileage may vary". Don't discount that. Look at the EPA test cycle and see if your driving is the same. That means SAME temps, NO A/C, NO wind, NO rolling resistance, no cars pulling out in front of you, no etc. They do these tests on a dynamometer not on pavement in the real world.

My sister lives in Huntington Beach and can't do much better in her '06 than 44 MPG around town and doesn't see how I get mid 50s in the summer in my '04 in Vermont. At the moment, I'm sitting just under 58 MPG on 550 miles on the tank. Well I can tell you from looking at her consumption screen when she picked me up at the airport in San Diego last October. She had WAY too many regen 'cars' on 7 green bars meaning she spends WAY too much time on the regen brakes. While green is nice to have it SHOULD NOT BE A GOAL, it means you are wasting a lot of kinetic energy unless you are coming down a hill.

Another reason is I pick my routes to some extent. I have one place where I can go straight 2 streets then turn left up the hill go 2 streets and turn right OR turn left up the hill go up 2 streets and turn right. There are:

• 1st route: 2 lights on the straight part and 2 stop signs . The first stop sign is ON the UP hill.
• 2nd route: 1 light at the right turn (which may be green so no stop) and 2 stop signs on the straight which is slightly down hill - electric .

The second stop sign is the same for both routes. It is small but it adds up when you find places to save all along your normal routes.

From my work side of town, I can go home 2 ways, one hits the interstate (which hits the MPG) the other goes down hill toward the lake. I can get 2 'free' miles on the second route because I can basically glide the first 1.25 since the hill is fairly steep and electric the last .75 since it is a gentle down slope and not drop the battery bars below 4. The second route takes longer though so one has to set priorities - MPG or time?

Learn the 'never stop and don't slow down' method of driving, it works in ALL cars. It is tougher in So. Cal than less populated areas. EVERYONE is in a big hurry to get to the next red light as SOON as they can. Look ahead and if the light turns yellow, why keep on the accelerator??? To waste gas and the brake pads at every red light? Also learn which signals run long and which run short. In some places you can see that the walk/don't walk signals are changing. Around here, once they start flashing red, you have about 10 seconds before they go solid and the traffic light goes yellow. If you aren't going to get to the intersection before then, why stay on the accelerator????

Zen out and do something people can't do in most cars - learn to glide. Put the display on the Energy screen. Once the engine is at temp (not that they give you any gauges to know) and you are under 42 MPH, let up on the accelerator SLIGHTLY. The Energy screen will show NO arrows at all and it will feel like you are in neutral. You have to be REALLY careful with your right foot, it isn't always easy to hold. But the car will slow a LOT less than if you are 'foot off the accelerator' coasting and regen braking. People will just think you are giving it a bit less gas. You aren't hampering anyone behind you, the signal will be red when all of you get there if you keep speed until the last possible second.

People get frustrated when they have to sit stopped. Nothing wrong with keeping moving but at a slower speed

[dogllama]

Hschen,

I feel your pain! I too cannot seem to get numbers in the 50's. I am averaging about 46 mpg now over 5 tanks and I have slowed my roll considerably.

After reading so many post about how effortlessly they get into the 50's, I too question wether I received an under-performing prius...

I am waiting for a roadtrip to see whether it is a factor of my environment/routes or not.

[ggood]

Don't feel bad, you and your wife are not the only ones having trouble seeing high mileage. The heat and humidity have been brutal here, and running the A/C really saps the batteries in these conditions. The ability to get those high numbers is very dependent on the particular type of driving you typically do, and the conditions you do them in. Some people just have ideal commutes and less brutal weather. I'm not a hypermiler, but here are the simpler things you can try:

1. The good news is, the A/C is so good, you can set the temp higher than you would in other cars (say to 76 to 78).

2. The tire pressures recommended by Toyota are much lower than necessary. You can raise the pressure at least 4 or 5 PSI without creating any discomfort for yourself, and with the added benefit of improving the handling.

3. Turn on your ECO button. The pedal response will seem too low at first, but you'll get used to it. (note, this also causes the A/C unit to run with a little less gusto).

4. Note what happens if you get off the gas pedal once you get up to speed, and then feather it lightly to the level needed to keep up your momentum.

5. Then read the thread suggested by efusco.

Originally Posted by hschen

Hello,

My wife took the delivery of our Prius II (in Winter Gray) in Phoenix last week and drove it to Irvine the next day. I instructed her to drive carefully - not to exceed 75 miles per hour and don't brake hard and coasting a lot. On her trip to Irvine, Prius returned only 47.8 mpg (displayed). I drove Prius the last 2 days and tried very hard to get high mpg by driving according to the ECO display and instant MFG display. In mostly all city driving, I never saw average mpg better than 50 yet !! No matter how slow and smooth I did (cars behind me were passing me and gave me the look), I don't see 51 mpg as advertised, not to mention 60-70 as some of you claimed you achieved. I only got about 46 mpg in mixed city driving in 2 days.
This morning coming to work, in the 36 miles of freeway driving on I-405, the average mpg rised to 48.8 mpg. I still don't see the ave 50 combined mpg. I suspect something not right with my Prius. A bit out of tolerance engine which may still within the manufacturing spec could consume more fuel than normal. I am really wondering how you guys/girls achieved the high 50 mpg. I saw a few even claimed high 60's. How could that possible? Crawling speed all the time?
How many of you out there are in the same boat as I am - suspecting our Prius is one of these under performing product from Toyota?

[hschen]

It's feel good to find a comrade.
I was afraid to tell friends on the forum about my background coming to driving a Prius -- my old commuting vehicle was a highly modified 1996 super-charged 4Runner. I don't want Prius frinds to think that I am a leadfoot. I maybe was one in 4Runner, but am not one in Prius since achieving high mpg is my goal on Prius purchasing.
I shall keep posting my mpg performance, if any improvement.
Thanks.

Originally Posted by dogllama

Hschen,

I feel your pain! I too cannot seem to get numbers in the 50's. I am averaging about 46 mpg now over 5 tanks and I have slowed my roll considerably.

After reading so many post about how effortlessly they get into the 50's, I too question wether I received an under-performing prius...

I am waiting for a roadtrip to see whether it is a factor of my environment/routes or not.

[alfon]

I believe we forgot one simple fact. If you drive from Phoenix Arizona to Irvine California you will be driving westbound.

See those windmills, you were driving against the wind.

This could be why you did not get the mpg you expected. But you got better than all the other vehicles on the road.

I drove from LaGrande Oregon to Seaside Oregon via Intestate 84.

I had a 25 + headwind for about 150 miles. I only got about 47 MPG on that leg.

alfon

[PeteJE]

I am at ~ 500 total miles. My avg mpg is 46 -48. I drive a lot of short hops, I live up in the foothills, I do 65 - 75 on freeways. I am pretty happy - this seems reasonable and in line with the EPA rating. I want to be above 50 consistently - I think it is possible for me once I learn the car better, do my more regular work commute (I am on hiatus in the summertime mostly), and stop needed lots of A/C on short hops.

My most exciting mileage was on a reset of tripA followed by a trip downtown where the route is an easy glide a lot of the time. I got a 65 mpg for that 17 mile leg, LOL.

I see lots of reports of high 50s and even 60s here. I don't think that is sustainable over the longer term average with this car... is it? I chalk these high numbers up to a great leg of limited time / distance. The only valid mpg numbers should at least involve a full round trip so the route anomalies can be canceled out. For example, on that 65 mpg leg, I got back home and was back at 49.8 mpg.

[hschen]

Hi, Pete,

I read about 'glide' many times here. How do you glide? Is that the same as coast? Maybe that's the secret of driving techinique for hypermilers.

Originally Posted by PeteJE

I am at ~ 500 total miles. My avg mpg is 46 -48. I drive a lot of short hops, I live up in the foothills, I do 65 - 75 on freeways. I am pretty happy - this seems reasonable and in line with the EPA rating. I want to be above 50 consistently - I think it is possible for me once I learn the car better, do my more regular work commute (I am on hiatus in the summertime mostly), and stop needed lots of A/C on short hops.

My most exciting mileage was on a reset of tripA followed by a trip downtown where the route is an easy glide a lot of the time. I got a 65 mpg for that 17 mile leg, LOL.

I see lots of reports of high 50s and even 60s here. I don't think that is sustainable over the longer term average with this car... is it? I chalk these high numbers up to a great leg of limited time / distance. The only valid mpg numbers should at least involve a full round trip so the route anomalies can be canceled out. For example, on that 65 mpg leg, I got back home and was back at 49.8 mpg.

[3PriusMike]

Originally Posted by hschen

It's feel good to find a comrade.
I was afraid to tell friends on the forum about my background coming to driving a Prius -- my old commuting vehicle was a highly modified 1996 super-charged 4Runner. I don't want Prius frinds to think that I am a leadfoot. I maybe was one in 4Runner, but am not one in Prius since achieving high mpg is my goal on Prius purchasing.
I shall keep posting my mpg performance, if any improvement.
Thanks.

The idea is to get more converts, so no judgements here.

There have been lots of tips, so I'll just give you one more.

Are you looking at your trip mpg and see it not going up and up? Try reseting trip A (or back to zero and see how well you do on each trip much more often. Try warming the car up (on the first part of a trip) then reseting A or B. Then see what type of mpg you get for the next 5 or 10 miles. If you are on a long freeway (not stop and go) or highway reset A or B and try lowering your speed 5 mph and see what happens.

You should be able to figure out a lot on your own by doing this with the positive feedback of knowing what worked in a short distance (short being at least 5 or 10 miles, not continuously downhill). Watching the mpg creep up and down after hundreds of miles is not the right amount of feedback to train yourself.

(I generally reset trip A on each fillup and use trip B for feedback on shorter segments)

3PriusMike (58.5 mpg on my second tank)

[a priori]

I'll try not to re-suggest many of the great things previously stated, but I have to do it this once: Read the Sticky articles under the fuel economy and newbie forum headings. (In particular, read the article efusco recommended: New owner? Want MPG help? Read this first.)

Otherwise, relax a little bit and realize you are practically at the EPA numbers right now. I know you think you've tried hard, but you've had the car only one week. Not one of us mastered fuel economy maximization in on year, much less one month or even one week.

Not only does the car need to break-in, but you do, as well.

Also, don't fret much about comparing yourself to those folks getting 60MPGs. Believe it, because they really are getting those mileage numbers, but they are driving the car to maximize fuel economy -- by leaving at 4am to avoid heavy traffice or by driving side streets to keep at lower speeds or by running without A/C.

Further: Those of us who live farther to the north do not have the heavy A/C demand right now. We will have the big heat demand and frigid ambient temps that will destroy our mileage during the winter. Your numbers should be consistent the whole year 'round.

Enjoy!