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Wrt

Discussion in 'Gen 3 Prius Fuel Economy' started by OZ132, Jun 23, 2009.

  1. OZ132

    OZ132 Member

    Joined:
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    Location:
    Northern Indiana
    Vehicle:
    2010 Prius
    Model:
    III
    We need a new gas mileage rating, which I have taken the liberty of dubbing WRT (Without Really Trying). I have always considered EPA ratings unrealistic, as in the old days I believe they were all made down hill in neutral with a tail wind. I also hear about Hyper-miling (drafting behind semi-trucks while pulsing and gliding and such, and that's not my cup of tea.
    When we first rented a Prius last summer, I decided that the only way to get an idea of "Real World" gas mileage, and make apple-to-apples comparisons with other cars, was to drive it exactly as I had always driven my other car.
    On the highway, that means keeping up with traffic (KUWT, if you will). In the Midwest, KUWT means usually at least 10-15 mph over the posted speedlimit, traffic and Smokey Bear permitting, with frequent passing, and sometimes being passed by those who can't go that slow.
    Driving from Northern Indiana up to Lansing Michigan on I-94,(Speed limit 70, KUWT 80-85) then around town a bit, then back, I averagaed "only" about 45 mpg (actual, checked at the fill-up).
    Since that was comfortably well over double the mileage I had gotten on my mini van, I was satisfied that the improvement was "significant". Of course Hyper-milers could get 3 or 4 times the gas mileage I get on the van, especially around town, but then they might get 30mpg on the van, coasting downhill in neutral looking for a tailwind.
    Apples-to-apples, WRT, and KUWT, I can find nothing that will seat at least two adults (oh, O.K. maybe a Harley) that even comes close to the Prius in mpg. That fact, after the promised Reliability, sold me.
     
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  2. JonathanK

    JonathanK Junior Member

    Joined:
    Feb 22, 2009
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    Location:
    Seattle
    Vehicle:
    2010 Prius
    Model:
    III
    I like the concept of WRT, but as a new convert to a Prius I am finding it difficult to drive like I used to. I cannot ignore the immediate feedback and the ability to shut the engine off by feathering the gas pedal. Once you are in, there is no going back :)
     
  3. Blauer Glimmer

    Blauer Glimmer Active Member

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    2017 Prius Prime
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    Prime Advanced
    :rockon:
    This is true for me, as well. I find myself actually doing the speed limit, feathering the gas pedal to make the arrows disappear and coasting to a stop. I've even experimented a bit with pulse and glide, though I find it annoying and would not do it with anyone else in the car who is liable to bop me over the head with the nearest available object.

    Guess you can teach an old leadfoot new tricks :)
     
  4. donee

    donee New Member

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    III
    Hi OZ...,

    Hypermiling does not consist of drafting behind trucks. The trucks go much too fast for the advantage to be better than just going slow (50 to 55 mph on metropolitan interstates).

    Coasting is used when there is no hurry to get a red light, or one does not want to have to get to a stop sign and still be going 20 mph. The slower speed one is at when one hits the brakes, the less is wasted, even in a Prius. Coasting is not used downhill to exceed the speed limit. Interstate Coasting is built into the Prius, just lift back on the pedal and it does it. Its not like a neutral coast in a towable AT or MT car.

    My first year of Prius driving was WRT, but not to your definition. I have a new name for that later on. And I got 58 mpg in the summer season consistently. This was right lane keeping up with traffic driving. Speeds were up to 62 mph. I was using the Prius as it was designed, but none of the hypermiling stuff. The main thing with the Prius is to get your accellerator pedal foot way back when your not in a traffic maneuvering situation. The car will then gear way high and cruise along at low fuel consumption. Do that, drive in a metropolitan rush hour situation, and you will get right on the old EPA.

    Yes, the OLD EPA is the WRT rating for the Prius!

    Hypermiling in the Prius is allot of the CleanMPG methods, but route selection and traffic timing has a very great effect due to the warmup cycles programmed into a Prius. My typical hypermiling summer time, no AC mileage is 65 mpg.

    What you are asking for is not WRT, its I don' give a f... - IDGAF mileage. In which case the mileage will be down between 45 and 50 mpg during the summer, runnin AC and doing 70 mph in the left lane, and mashing the brakes when traffic comes around a corner and slows suddenly in a second generation Prius. The 50 mpg end is when traffic wont let you go faster 70 mph, and it flows smoothly. The new 2010 Gen III should do better. Probably right at 48 mpg in this kinda of driving. Which is the EPA Highway. The EPA tests tend to underate the Prius but the cycle does not go over 70 mph, I believe. SO going over 70 mph, up to 80 ish, and taking into account the underate, 48 is probably a good guess. Unlike traditional cars where the old EPA severely overated traditional cars, and the new EPA is much closer.

    The reason for the underate is hills. In the real world the Prius is efficient uphill, and recovers energy down hill. On the dyno, there are no hills, although there is a simulation of aerodynamic drag.
     
  5. CenVal

    CenVal Member

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    I guess I will not be using the WRT concept when I purchase by Prius. Having installed a scan gauge in my current Toyota truck, I have gone from 16 mpgs to 21-22 mpgs consistently. What I like about the Prius in particular, is that it allows the driver to minimize fuel consumption in all driving conditions. This to me is an environemntal and economical benefit. I am not a hypermiler but have used some of the basic fuel economy principles to improve my MPGs without impeding traffic flow. I hope to get 55+ mpgs when I do purchase my prius w/o getting in the way of other drivers.