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Gen 4 - Easiest Vehicle to Attain High MPG

Discussion in 'Gen 4 Prius Fuel Economy' started by Tideland Prius, Jul 22, 2016.

  1. Tideland Prius

    Tideland Prius Moderator of the North
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    The Gen 3 made splashes in being able to get a solid 50mpg and most people were close.

    The Gen 4 initially looked like a half-step up with a 2mpg increase to 52mpg combined (non-Eco). But of course we've seen people easily beating it and they're not in Florida (or any other flat place).

    We finally had the opportunity to take our Gen 4 out on the highway on a short trip to the U.S.

    • It was mostly highway with some B-Roads and some city streets.
    • Highway limit was 60-70mph so I set the DRCC at that to see what kind of mpg I can attain
    • DRCC was used exclusively on the highway. No hypermiling/SHM. DRCC was used even in heavy traffic (got to use the the full-speed range twice as traffic came to a stop)
    • We have the 17" wheels
    • A/C was on in Eco mode
    • Not sure it matters but it was about 50/50 in Normal mode and Eco mode for driving modes
    • No luggage since it was a day trip but S-Flow would be in "All Seats" mode since the car had 3 people

    The result was:

    IMG_7176.JPG

    US Conversion:

    Trip Distance: 328 miles
    Average FE: 57.3 mpg
    Average speed: 41mph
    Temps were in the mid-high 60s.


    There is no way I can attain 57mpg in my Gen 3 without some mountain involved so I can drive downhill in EV Mode. The last time I got those numbers, there was a net elevation loss over 700ish miles. The car would go into EV Mode on slight descents on the highway (in 60mph limits). The higher engine-off speed definitely helps highway mpg. (Recall that the engine-off limit is 70km/h or 43mph for the Gen 3 and 60km/h or 37.5mph in the Gen 2)
     
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  2. Ogo

    Ogo Prius Owner since 2008

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    I am also hitting magical numbers around 4,1 l / 100 km average. :)
    Every working day making around 175 km. 110 km out of those are on highway with speeds in range 100-120 km/h measured by GPS.

    Everything else is approximately the same like with you, 17" wheels, A/C on Eco, DRCC on highway, temperatures around 20 deg C during morning commute, around 30 deg C during afternoon/evening commute.

    Let's wait and see what winter will bring in 6 months. :whistle:
     
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  3. Coast Cruiser

    Coast Cruiser Senior Member

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    Tideland, how many total miles do you have on the car now? Is it considered "broken in" yet? What color did you get. This is the first time I've seen you mention your new Gen4. (I must have been sleeping.)

    The radar cruise control sounds like a very nice feature, especially on a long highway trip. (I don't have it.) I'm curious, has anyone drove the same exact route with the radar operating, and then drove it again without the radar? I'm wondering how the gas mileage would compare; And if the gas mileage would be affected, one way or the other.

    Thanks.
     
  4. Tideland Prius

    Tideland Prius Moderator of the North
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    ~3,000 miles so definitely broken in. We got Blizzard Pearl.

    I still own the Gen 3. The Gen 4 is the family's vehicle (upgraded from the Gen 2).

    It is a nice feature on the highway. The Gen 4's DRCC is much smoother than the Gen 3. For better or for worse, the acceleration is slower when a car changes lane. It's good if you're in your own lane and slowly accelerating back to the set speed. It's bad if you've changed lanes (i.e. you have to accelerate harder on your own to pass). I'd take the smoother Gen 4 over the more rigid Gen 3's system.
     
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  5. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    It would depend on your driving style when having to accelerate to catch back up to your set speed. I accelerate slower manually than my radar Cruise control does. Especially if it happens to be uphill. So, I am pretty certain that the cruise control has a small negative effect on my gas mileage.
     
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  6. thunderstruck

    thunderstruck Active Member

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    I've noticed the same thing about my CC. Seems like the hamsters that power the car are in more of a hurry than I am to get back up to speed. Have not yet had a chance to see if Eco vs Power has any effect on auto acceleration. DRCC is so nice in the heavy traffic we have here though. (Not I mind heavy traffic because that just means better mileage.) It's just so ridiculously easy to get the car up over 60 MPG on my daily commute.
     
  7. jbkendrick

    jbkendrick Active Member

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    I've done that on my commute to work and find that if I drive conservatively, it is about the same with and without DRCC. Note that this is in ECO mode both with and without DRCC. Most of this includes some stop or slow and go traffic over the 25 mile commute. While the DRCC slows and stops more abruptly than I would, in ECO mode it accelerates back to speed slower than I would, so I think this is what evens it out. I love the comfortable seats, smooth and quiet ride, but the single feature that helps me to relax while driving is that DRCC, It's almost like being on an amusement ride rather than driving a car. While of course I have to steer and pay attention, it is great getting to the highway, turning on cruise and settling back with my cup of coffee. Can you tell that I am really enjoying this car!!! J
     
  8. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    The rate of accele
    The rate of acceleration does change dependent on the mode you are in.

    All that and I think the added layer of safety of the car looking to keep that safe distance from the car ahead.
     
    #8 krmcg, Jul 22, 2016
    Last edited by a moderator: Jul 22, 2016
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  9. jbkendrick

    jbkendrick Active Member

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    Yes it does. If you want more normal acceleration with DRCC, you need to be in normal mode. Instead of switching from ECO to normal when I feel like the person behind might get annoyed, I'll just ease on the accelerator to get back to speed a little quicker and then let go when I'm back up. MPG will decrease with DRCC in normal mode. I think Toyota did a great job with the ECO mode and I stay in it almost all of the time. J
     
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  10. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    I live in the ECO mode. Tried the others and quickly abandoned them.
     
  11. jbkendrick

    jbkendrick Active Member

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    Absolutely, that is another thing I've really appreciated. DRCC keeps you at a much safer distance than I would normally drive. Do some folks use that to get in front of you? Yes, but that's ok. I can even say this car and DRCC has decreased my stress level on the commute. J
     
  12. pakitt

    pakitt Senior Member

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    I am getting without effort 4L/100km. On my last trip to Stuttgart, driving when possible at around 150km/h (speedometer), I ended up with 6L/100km with an average speed of 122km/h (that is high) - 5.5L/100km average (77km/h average) if I consider the 22km with 3.5L/100km drove into town before I could hit the highway. On my way back I had 5.0L/100km -at 109km/h average. Essentially 15-20% less fuel consumption with 15-20% higher average speed...! (all details with US values here)
    I never felt I had to "hold off" to get better fuel consumption.

    As reported from others, the DRCC acceleration style is dependent on the mode you are (which is a cool idea). ECO is way too slow for Germany, so I did the drive to Stuttgart mentioned above with DRCC and PWR mode - because I can set the AC to ECO independently from the mode, the setup is really great.

    I have ECO for city traffic. Normal for suburban. PWR for highway. Because the AC can be set to ECO the whole time, the 3 settings now are essentially to tell the DRCC what to do :D

    Same here - but I need to set it to 1 bar on the highway otherwise I piss off other drivers and they will cut in. 1 bar is still more than what I did in the past - which is a good thing!
    Also with the DRCC, because it mimics the preceding drivers driving habits, it is really scary to see how bad people drive - they brake last minute and continue driving really fast when the signs say, e.g., to slow down because of roadworks. And speed signs in Germany are 90% really meaningful - not just random stuff forgotten...
     
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  13. Mendel Leisk

    Mendel Leisk Senior Member

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    @Tideland Prius Yes, the jury is in, and gen 4 is delivering a phenomenal increase in mpg, without trying hard.

    Still, our situation: low miles, fixed income, carefully maintained 2010 Touring, trading up doesn't make sense. Guess we stay with our baby. :) Plus, sadly, I'm dismayed by the new car exterior styling and interior ergonomics. Ah well.
     
  14. Tideland Prius

    Tideland Prius Moderator of the North
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    Really? Good to know. Thanks!

    Hmm, I noticed that the A/C goes to "Normal' when you cycle from ECO to Normal. I have to press the ECO Heat/Cool button to put the A/C back into ECO mode.

    i.e. even though there's a separate button for ECO Heat/Cool, it's still tied to the drive mode when you cycle through the drive modes.

    That's fine. Maintaining personal finances is much more important than a new toy. I still have my Gen 3 with average miles. It still looks new inside and out (if you ignore the pitted front bumper). Even the steering wheel isn't particularly worn (I've seen shinier/smoother leather-wrapped steering wheels on 3 year old cars).
     
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