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first fill up for a c 3

Discussion in 'Prius c Fuel Economy' started by col127, Jul 31, 2012.

  1. col127

    col127 Member

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    hi all,

    my first fill up on my c3 was pretty disappointing. fuel mileage was about 41mpg. mostly highway driving. first tank only got me about 350 miles. a/c always on.

    highway driving, avg speed was around 65mph-71mph. trying to use the gliding techniques, coasting techniques. filled up my tires to 39/37.

    i find it was pretty hard to get mid 40 mpgs...

    maybe i still need to learn more how to drive this thing and I'm' really hoping it gets better since the reason we bought this car was the amazing fuel economy i've been reading about.... hoping this is part of the breaking-in process?

    best city drive was 54MPG so far...
     
  2. priusCpilot

    priusCpilot Active Member

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    Its critical to break in the engine properly so no full throttle applications. If you set the AC very low like 72 or less it does use a lot more fuel. I find 78-80 very comfortably when I need AC. Running in ECO will also help. Keep your speed at 65mph or less and slow down on steep grades until you reach the peak so you can glide down. I went 75MPH with temps of 110 outside AC at 78 and still got 45-46 mpg on a long road trip. So 41 mpg is way off ???

    To add I had the CC set to 75mph so even up hills it was full RPM haha. I set it and forget it and still got the 46mpg shown with two passengers and luggage. I don't know of another car that can do that under the same conditions and get this MPG?
     
  3. ricks06

    ricks06 New Member

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    Just came back from a trip to Illinois from Houston with my 2012 Prius C averaged 49 MPG over the 2900 mile trip. My speed ranged from 68 to 78. The car now has 6900 Miles on it. I was hoping for a little better but 49 isn't really that bad.
     
  4. col127

    col127 Member

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    oh i never had the ac very low - had it around 76-78... car has always been in eco mode! i'm still learning... just was disappointed w/ the first tank...

     
  5. col127

    col127 Member

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    oh wow - that's pretty good.... did you have ac on the whole time too?
     
  6. priusCpilot

    priusCpilot Active Member

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    Did you measure how much fuel was there on the first fill up? If not then just go to the first full click off at the pump and measure from that after trip reset. Even if you drove with ill intent you should not have gotten 41mpg. Something is off?
     
  7. col127

    col127 Member

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    the dealer was supposed to have filled up the tank for me when we picked it up to the top - the car only had 8 miles on delivery. i filled up my tank last night - was about $27 dollars @ $3.69 a galloon = 7.317 gallon . the odometer was around 300 miles on fill up.
     
  8. priusCpilot

    priusCpilot Active Member

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    Interested to see how this tank turns out? Post back and let us know.
     
  9. VagrantNova

    VagrantNova Soon-To-Be Prius C Owner

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    Just because the dealer is supposed to fill the tank doesn’t mean it was entirely filled. (People around here seem to generally be in agreement that the first tank is a crapshoot in that regard — even if it looks full on delivery.)


    Mid-40's sounds fairly realistic for a first tank, mostly on highway:
    • You’re still in break-in period and people generally report that mileage improves quite a bit over the first three or four tanks. (High 40’s on first tank to approx mid 50’s by the fourth tank in that example.)
    • The C is less efficient at highway speed than the Liftback, due to the slightly higher drag coefficient (Cd=0.25 for third gen Liftback, Cd=0.28 for the C) and slightly smaller engine. Due to these factors, the faster you go (above 60mph), the harder the C has to work to keep you going at that speed. Still better than most cars, but something to keep in mind. (As they say, “‘C’ stands for ‘City’”.) Note that the EPA mileage is 46mpg highway and you should likely average just above that if you’re pulling mostly highway (>85%) once you’re broken in.
    • The hybrid battery is located under the rear seat and is pretty susceptible to warm temperatures. If your interior is really hot or if you have something obstructing the battery vent, the hybrid system will lose a bit of power and efficiency.
    If you’re using the MID screen to help you out, a tip: accelerate to your cruising speed quickly. (As per this post, it’s best if you try to get to the far end of the ECO bar, just before you hit PWR.) Acceleration is killer on mpg and the hybrid system cruises rather efficiently, so you should generally try to get up to speed as quickly as possible. (Also want to abuse the fact that the electric motor provides a lot of the acceleration help, as long as it has some battery charge, so there shouldn't be a significant mpg impact during those moments you’re accelerating fast.)
     
    F8L likes this.
  10. WD0AFQ

    WD0AFQ Active Member

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    Here is something I found: the lower the fan speed, on the air, the better the fuel mileage is. When I can I run it on low. Try it. Get out on the hiway and set the cruise. Start flipping from high to low and watch the mileage go up. This is easier to see if you have a ScanGauge, that shows instant mileage.
    I also got a "full tank of fuel" but I know it was not completely full. At 100 miles it was below full. Am not complaining but I am sure the next tank, when I fill it, will show higher mileage.
    This car takes some "playing around" to get the best mileage. I have never owned a hybrid until Friday. I still have not got good enough to hold the accelerator pedal so I can "glide" over 200 feet. I know I will get it soon.
    We love the car for what it is.
    Dan
     
  11. col127

    col127 Member

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    Thanks for the tips all. Will report back when I fill up next! This morning's trip to work was better - averaged 50.4MPG - and that was less than a 15 minute drive. All city.
     
  12. F8L

    F8L Protecting Habitat & AG Lands

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    Be careful with this kind of advice. In general it is not more efficient to accelerate quickly. Slower is better within reason. In the GenIII LB it is best to keep the HSI indicator about 3/4 of the way to the Power section which equates to about 1500-1700RPM. The less torquey 1.5L may need to rev up a bit higher much like the GenII but RPM will likely still need to be just shy of 2000RPM. Basically keep it out of the Power section of the HSI. For people who are not familiar with hypermiling, accelerating briskly works better than super slow poke. Mainly because when they assume they should accelerate slowly they simply go too slow. There is a happy medium.

    A more advanced technique requires the use of EV-only acceleration up to 15mph-25mph (depending on conditions and SOC) then lighting off the ICE to reach your desired speed. Combine this with DWB (Driving Without Brakes) and smart regen braking and you should have no problem pulling off 65mph+ tanks if your commute is decent. :)
     
  13. PriusCinBlack

    PriusCinBlack Member

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    What you're saying is usually true, but I think the reasoning is that the quicker you get to the point where you can shut the engine off and are just gliding or on EV, the better your mpg will be. It's a question of how much energy is wasted maintaining engine speed for the extra few seconds if you don't accelerate as quickly.

    That said, I usually don't accelerate all the way up to the yellow end of the ECO bar- I also go maybe 3/4 of the way up.
     
  14. F8L

    F8L Protecting Habitat & AG Lands

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    I understand. I was "raised" on that idea but talking with Wayne Gerdes and other experts I have been informed otherwise. My point is to make sure others know that there are other ways of increasing fuel economy that is contrary to group think. :)
     
  15. col127

    col127 Member

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    Had a GREAT trip to work this morning - a short 10 minute city drive but I managed to get 63.7MPG!! Switched my display mode to the ECO Score this morning and found that helped me more than having it at the car screen (showing the errors) because I could graph my acceleration better. Before, my short drive to work would net at best, around 52MPG. Now, just need to figure out how to drive this car better on the highway... hoping my 2nd tank will be a lot better for MPG! :)
     

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  16. col127

    col127 Member

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    Filled up again yesterday - my car has been averaging around 45.7MPG since I bought it. Already got around 750 miles on it in just under two weeks. Mostly all highway driving. Still learning to drive it better - find it hard to get really good MPG scores when on the highway still - I'm doing a lot better driving around the city when I can use the EV portion of the curve - but I can't seem to engage that at highway speeds (I think the EV portion doesn't apply when you're over 45MPG?). How do you all get the great MPG numbers on the highway? :)
     
  17. F8L

    F8L Protecting Habitat & AG Lands

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    Slow down to 60mph or lower.

    Glide down hills or large overpasses. Glide as long as you can on off ramps.
     
  18. PriusMan140.6

    PriusMan140.6 New Member

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    Just completed my first tank of fuel here in Phoenix, AZ. 112 deg temps out. I averaged 43 mpg. Tank must have been bone dry, it took 8.7 gallons. It's common for fuel tanks to expand here in the heat. In any case, this with with pulse and glide technique and 65 mph on freeway. A/C on LOW temp and high fan, all the time. My guess is the heat is really playing havoc with the battery system and the constant A/C is wrecking my mileage. Thoughts?
     
  19. WD0AFQ

    WD0AFQ Active Member

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    We just got the windows tinted today. I think that will help stay a little cooler inside. If so, can keep the fan on the ac set lower. That will save some fuel. I have watched the mpg go down when I click the fan to higher speeds, using the instant mpg on my ScanGauge. I keep the thermostat on 74 so far.
    We spend a lot of time in your area. Have 2 daughters out there.
    Dan
     
  20. PriusMan140.6

    PriusMan140.6 New Member

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    I just made a trip this weekend to Flagstaff and back (280 miles) with the car full of people and stuff and my bike rack on the back and still managed 49 average. Seems like efficiency is going up each tank.