1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Less MPG than I had hoped

Discussion in 'Gen 2 Prius Fuel Economy' started by exces6, May 14, 2005.

  1. DonDNH

    DonDNH Senior Member

    Joined:
    Feb 3, 2004
    1,711
    654
    0
    Location:
    Nashua, NH
    Vehicle:
    2016 Prius
    Model:
    Four Touring
    <div class='quotetop'>QUOTE(Rollerblade\";p=\"89895)</div>
    WOW! Your done some hard driving to pass the 3 million mark in just over 5 months. :mrgreen:
     
  2. galaxee

    galaxee mostly benevolent

    Joined:
    Mar 14, 2005
    9,810
    464
    0
    Location:
    MD
    Vehicle:
    2005 Prius
    That's about 950 mph over hour of every day you've had the car! Whew!

    Haha.

    Back on topic- I drive in a hilly area. My usual commute is less than 3 miles and when I'm heading there and back 2x a day I get around 45 mpg. I've had some time off and my mpg is up to 48.

    I think my increased mpg is due to a better understanding of the car coupled with warmer weather and longer average trip time. I finally found my "prius driving groove"

    It just takes a while I think.
     
  3. Rollerblade

    Rollerblade New Member

    Joined:
    Apr 11, 2005
    26
    0
    0
    Location:
    Tillsonburg, Ontario
    A comma makes a great difference ......3,000 kilometres or 1,800 miles
     
  4. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    44,768
    16,017
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    isn't 4.7L/100km = 50mpg = 60mpg?
     
  5. Rollerblade

    Rollerblade New Member

    Joined:
    Apr 11, 2005
    26
    0
    0
    Location:
    Tillsonburg, Ontario
    According to my chart....4.7 = approx 62MPG i.e. The Canadian Imperial Gallon which is larger than the US Gal.
     
  6. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    44,768
    16,017
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Hmm, maybe I'm rounding off?

    I used 235.21/ (L/100km) to get US mpg, 282.48 to get Imp. Gal
     
  7. GaithersburgPrius

    GaithersburgPrius New Member

    Joined:
    Mar 31, 2005
    13
    0
    0
    <div class='quotetop'>QUOTE(gschoen\";p=\"89881)</div>
    I completely agree!! I average about 45mpg in this hellish DC traffic. The way these fools around here drive, you have to "blend in" or get run over. 45 is about as good as it gets for me. Still not complaining though :)
     
  8. tomdeimos

    tomdeimos New Member

    Joined:
    Feb 16, 2004
    995
    2
    0
    Location:
    Lexington, MA
    I too am upset with my mileage, especially when it drops under 50 mpg!

    But I am beginning to see why I can't do much better, and the things mentioned by everyone are critical, like excess speed, short trips, etc.

    I think the effects of temperature though mentioned, are not emphasized enough however:

    My commute is short, about 12 miles, and I can bring up my average by 5-10 mpg depending on the weather when I deviate from my normal route. Due to traffic and time constraints, I don't do this often, but it helps every time I try it: Key is to alter your normal route to do three things:

    1 pick slower roads.
    2 pick roads you don't have to stop on (hard to do along with 1, without leaving early to avoid any traffic.)
    3 pick a fast road to drive on till the car is warm and then go on the slow roads for the last part of the trip. Move to a valley so everywhere you go is uphill for a while during
    warm up would help too! This is most critical, since my car warm up can be as long as 15 minutes at city speeds, but is often OK after 5 minutes on the highway.

    It also helps to drive on routes in hills that have gentle down slopes and steeper up slopes, to minimize braking and maximize engine off.

    If I drove this way to work every day, I could get my average up from 49-50 to over 55-60 I estimate.

    The other effect of temperature I notice is the warmer it gets the better my mileage around here, where we've had a pretty cool spring. On mornings above 50 degrees I see a jump up in mileage of over 2 mpg. By 70 degrees it is doing as great as I could wish for, with lots of 75 to 100 bars on the graph after the first low one.
     
  9. Jaguar88

    Jaguar88 Member

    Joined:
    Apr 26, 2005
    172
    0
    0
    Location:
    La Crescenta, CA
    Vehicle:
    2005 Prius
    Take a road trip. That way you can find out what your car can really do.

    And to the above suggestions, try to avoid congested traffic, besides hills its the biggest millage killer.
     
  10. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,191
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    Some of us are questioning the 'push the car hard during warm-up' concept. The thinking is this. The ECU will make the car use a richer fuel formulation whether it needs it or not for a fixed time AND until other temperture criteria are met.

    So, when going fast or uphill during warm-up you may accomplish reaching temperture faster, but you still aren't out of the time phase and thus are using a richer fuel blend than you otherwise would during times where fuel economy is already at its lowest. So you're burning even more fuel than if you'd have let the car sit idle for 60 seconds.

    The Japanese gurus have been playing with this and seem to be concluding that the most efficient way through warm-up is to start the car and not move at all until the ICE shuts off at the end of warm-up.

    I don't swear by either answer, I really don't know the answer. I used to very much believe the drive it hard during warm up, but am starting to think that may not be the best answer.
     
  11. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    44,768
    16,017
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Unless they're rolling hills and one downhill slope has enough momentum to carry you through to the next one in EV mode without pissing the guy behind you. =)


    Hmm, I would think driving it lightly-moderately during warm up would be ideal. With a regular car, you do not want to do full throttle starts when the engine is cold so I figured the same would apply to the Prius.
     
  12. Ray Moore

    Ray Moore Active Member

    Joined:
    Mar 28, 2004
    857
    52
    0
    Location:
    Texas Hill Country
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Evan- Have you tried to drive it no arrows during warm-up? I find it to be the best way. I have milestones that I compare my drive to each day, like in the morning how much does my average drop by the time I reach the mailbox(2 miles from home). Another is where am I when I get back to the average that I had when I started. This is how I've improved my techniques.

    Sitting in the driveway until the engine stops is a total loss as is driving it at normal acceleration rates.

    The best is when I drive with no arrows in or out of the battery until it is warmed up. Takes about 5 minutes and about 2 miles to get to stage 4. Usual average for the first five minutes is around 30 MPG unless my battery was low to start which puts me at around 35 MPG. My first five minutes and two miles has a gain in altitude of around 150 feet.
     
  13. tomdeimos

    tomdeimos New Member

    Joined:
    Feb 16, 2004
    995
    2
    0
    Location:
    Lexington, MA
    Evan,

    You make some good points regarding the rich mixture, but I find getting to stage 4 is critical to me getting any kind of good mileage. Also while it is bad and running rich I find the rpms are higher and I can vary my speeds a lot all at the same mpg on the instant graph! So pushing to a point at least seems to warm me faster but at the same bad economy for this part

    My experience so far has been that I regularly see a difference with my routes to work. I have several choices but they boil down to two or three effectively: I have a mile or so of gentle warm up getting from my house to the main roads. Then I can go on a highway at 55 mph or take town roads, and streets going 30 to 40 mph. When I start with the highway my car warms up on cool days like 40 degrees F ambient, by the time I get half way to work. I then take the side roads at the 30-40 mph.

    I can't measure trip mileages right now, since I am using the display for tank mileages to check accuracy. But the bar graphs show something:

    The fast route all the way gets me bar graphs that may get me three bars on the graph of say 20 40 and 55. The fast route for the first half gets me 3 bars of 20, 55 and 75. The slow route all the way except in quite a bit warmer weather might get me 3 bars of 20, 30 and 40 mpg with maybe a fourth one still under 50 mpg. The whole commute is between 15 and 30 minutes, depending on the route, 12 to 18 miles. There are some long traffic lights on the slow routes too, making the engine warm up even more difficult.

    The colder the weather the worse it gets and the greater the difference, except that in winter I stay on the fast route all the way because the engine cools off too much if I don't, and I lose the benefit of the slow roads and get worse mileage. Cold weather keeps my engine under 160 degrees the whole way to work, and under 120 degrees on the slow roads, so it is then easy to never get to stage 4.
     
  14. V8Cobrakid

    V8Cobrakid Green Handyman

    Joined:
    Jun 6, 2004
    3,790
    152
    0
    Location:
    Park View, Los Angeles, CA. U.S.A
    Vehicle:
    2004 Prius
    Model:
    N/A
    not sure if it was mentioned. i browsed and didn't see it.

    the prius has a break in period around 15k miles. Some are able to get good gas mileage off the log, congrats to them. I was stuck n the 40's. then around 15k miles to 20k miles my mpg jumped into the 50's.. then i was able to achieve 60 one day. this was during winter too. today i achieved 58mpg. if i didn't have such mixed driving i could get higher. I also have about 38900 miles on my prius.
     
  15. Graz

    Graz Member

    Joined:
    Feb 22, 2005
    178
    28
    0
    Location:
    San Diego, CA
    Vehicle:
    2005 Prius
    Model:
    III
    No. I don't get near the mileage that many of you do. But I am still trying. I can tell you that I think I am saving about $100.00 a month in fuel costs when I compare to my '98 Blazer. I drive about 250 miles a week and the difference between 14 MPG and 46MPG is amazing. If Coastal Tech would ever respond to phone calls or e-mail I may get some of their accessories and improve my mileage. But I have lost hope.

    Thanks for all the suggestions everyone. You keep me trying!
     
  16. V8Cobrakid

    V8Cobrakid Green Handyman

    Joined:
    Jun 6, 2004
    3,790
    152
    0
    Location:
    Park View, Los Angeles, CA. U.S.A
    Vehicle:
    2004 Prius
    Model:
    N/A
    you only have 7k miles. I'm curently at 40k miles. my milage didn't go above what yours is untill 15k. around 20k i was able to achieve 50 - 60 mpg. It's all part of the break in period... er.. " break in " period.
     
  17. dipper

    dipper Senior Member

    Joined:
    May 4, 2005
    1,242
    252
    0
    Looks like checking tire pressure has not been mentioned yet.

    My dealer delievered my Prius with 31PSI all around. Drove it to work and back for a week and got 42mpg average. Check on the next weekend and found 31PSI, so added air to 36/34. Resulted next at 46mpg. That is a lot of difference just by adjusting the tire pressure.

    And some of the folks are doing 42/40 on their current Prius model... so that might account for 50s range.
     
  18. Ken S

    Ken S Member

    Joined:
    Jan 13, 2005
    191
    2
    0
    Location:
    Pittsfield, MA
    Vehicle:
    2005 Prius
    Model:
    Five
    I have about 4K miles on my 05. I live in SE Florida and keep the A/C on auto and 75. My average mileage is in the 42MPG area. The average temperature in my area during the time I've owned the car hasn't been much over 75 (ranging from 65 - 85)

    On highways in this part of Florida 55 MPH isn't really a safe option as most are either 65 or 70 zones (I-95 or Floridas Turnpike). The Prius mileage at 65+ is under 40MPG. I've experienced this on several trips up the Turnpike to Orlando and/or Tampa.

    My around town driving is usually very short trips...and even when well planned and several stops it's going to be under 10 miles. I'll get somewhere around 42MPG in these area.

    I do not drive the car hard and try to focus on improving mileage where I can.

    Tire pressure is at 40/38.

    I have experienced the best MPG when I can get on a road and drive somewhere around 35 MPH for a while...but those times are few and far between.

    I'm not unhappy with the mileage although the EPA numbers are so far off on this car it really should be noted. Other cars I've owned may be off from the EPA but by very small amounts. A VW diesel Jetta a buddy owns does as well MPG wise for the most part...and better on the highway.

    This isn't meant to downgrade the Prius...it's a great car and nice technology...but overhyping the mileage is going to cost them in the end.
     
  19. Ray Moore

    Ray Moore Active Member

    Joined:
    Mar 28, 2004
    857
    52
    0
    Location:
    Texas Hill Country
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Ken-
    You're experience is as far off from the average as mine is. I'm currently getting 63.1 MPG for the last 263 miles and got over 60 MPG for my last two tanks, both of which went over 700 miles. I expect to get 800 on this tank. I drive 30 miles each way from a rural home to a job in the city.(Austin, TX) Highway miles make up about 1/2 my driving, while the remainder is split between rural two lane and city streets. There are several people on this board who achieve similar results. My wife is getting between 51 and 55 on her tanks. The tends to not pay much attention to it. I have two friends that drive them. One gets 50 on his 70+ mph interstate commute and the other gets mid 50s in his city commute. Both their cars are fairly new. The strategy that we all employ is to minimize the use of the electric motor, anticipate stops, and avoid excessive braking.

    If you are getting numbers similar to a Jetta, you might want to have the car checked out. The only time I get numbers that are less than the EPA estimates are on the Interstate at speeds above 70 mph. Others will experience low numbers with numerous short trips. The Jetta will suffer the same reductions under those conditions.

    You should experience 50 MPG on the interstate at 70 mph and 40 MPG at 80 mph. This will be reduced by adding passengers, heavy loads, heavy AC loads or cold temperatures.

    Of coure, YMMV.
     
  20. Ken S

    Ken S Member

    Joined:
    Jan 13, 2005
    191
    2
    0
    Location:
    Pittsfield, MA
    Vehicle:
    2005 Prius
    Model:
    Five
    Ray,

    I'll have the car checked out by the dealer because I'm nowhere close to that. Although several magazine reviews have seemed to put the actual MPG around 42 (Car & Driver type reviews) and there seem to be a number of people in the forums experiencing the same thing. Perhaps Toyota made changes to the car?

    Anyway, we can always say there's a difference in the way we drive in the city, but at 70 -75 MPH my car gets around 39 - 40 MPG and that's over an extended period using cruise control with little wind and basically flat and straight (Florida) roadway.

    I do believe that if I drove the car 30 miles each way on lower speed roads without much traffic or traffic lights that the mileage would be over 50. I've seen that myself....but that's not what anyone would consider "City" driving where the car is supposed to excel (EPA had 50 Highway and 60 City if I remember correctly).

    I'll bring it in to the dealer and see what they can do/suggest.