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Short, multi-stop commute strategies

Discussion in 'Gen 2 Prius Fuel Economy' started by Shorty, Jul 8, 2007.

  1. Shorty

    Shorty New Member

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    Hi there.

    I'm taking delivery on a new Prius this week and am curious about strategies for improved MPG in driving conditions that seem ill-suited to the "optimal" conditions typically discussed here. Basically, the situation is that I live in a suburb that used to be farmland with poor roads on a 1-mile grid with 4-way stops at the intersections. The farmlands are gone and the farmers are rich, but the crappy roads and 4-way stops remain, mocking all of the lead-footed resident yuppies. Here's a summary of the conditions that apply to me when K-12 schools are in session.

    1. A short (500 foot) drive followed by a lengthy (10 minute) stop (waiting for my 10-year-old's school bus to arrive).
    2. 250 feet of driving, followed by a forced stop at a neighborhood exit.
    3. 750 feet of driving, followed by a 4-way (forced) stop.
    4. 500 feet, then another 4-way stop.
    5. 1 mile (45mph limit), then another 4-way stop.
    6. 0.5 mile (45mph limit), followed by a traffic light with a 75% red probability since the opposing road is a state highway.
    7. A six-mile drive, with speeds posted at 50mph, moving down to 40mph as the city center approaches, with seven traffic lights along the way.

    I'm most curious about handling the sequence of 4-way stops. Call me crazy, but this sounds like a situation where forced EV mode might make a lot of sense. There is typically 15 minutes of driving in step 7 because of poor traffic light sequencing, which would allow the ICE to warm up the cat and top off the battery. I have no problem at all going under 40mph for the first six steps, even if I annoy a SUV-driving power mom for a few minutes.

    Thoughts?

    Doc
     
    #1 Shorty, Jul 8, 2007
  2. JimboK

    JimboK One owner, low mileage

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    Welcome, Doc, to PriusChat and Prius-dom!

    Sounds like you've gotten a great start on your homework. I have a couple of suggestions.

    First, have an engine block heater installed. You can buy them here, and FireEngineer, a PC member in the Chicago area, installs them. Second, familiarize yourself with the 5 stages of Prius hybrid operation described here, in particular what it takes to get ICE to shut down down in S4 operation. Between the heater and knowing how to induce S4, you will have ample opportunities for ICE-off operation fairly early in your ride.

    From there, continue your study here and learn how to accelerate and "glide" for maximum fuel economy. The frequent stops all are good opportunities for applying the glide technique, especially if you're not bothered by impatient drivers behind. Here's a great place to learn about maximizing fuel economy, if you haven't seen it yet.

    You could consider an EV switch, but that can be misused easily. I'd suggest you get the car and grab the low-hanging fruit. Meanwhile, study up on the switch and its uses as you learn the car's behavior in your situation. Then you'll have a better handle on how and when -- or even if -- it could help you.

    Good luck!
     
    #2 JimboK, Jul 9, 2007
  3. chuck_k

    chuck_k New Member

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    The Prius is meant to maximize fuel efficiency in all situations. It is NOT meant to give you 60mpg no matter what.

    In your situation, all cars will suffer, including the Prius. The difference is, with your other car you didn't have a little screen telling you HOW much your car was suffering.

    Be happy that the Prius will get the efficiency it does get under those conditions, and that you're not getting the horrible lack of efficiency that the other car got.

    Don't like it? Then move.
     
    #3 chuck_k, Jul 9, 2007
  4. FireEngineer

    FireEngineer Active Member

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    <div class='quotetop'>QUOTE(JimboK @ Jul 9 2007, 06:50 AM) [snapback]475422[/snapback]</div>
    Yes, Yes...must get engine block heater and block most of your grill. For your stop sign sequence the key as Jim said is to glide. Without a ScanGauge or CanView, best thing to do is to accelerate one-quarter to one-third of the distance and glide the rest of the way to the stop sign. With practice you will find the best rate of accel and end speed to start your glide, traffic considered.

    If you get the engine block heater and would like me to install it, I would be happy to go over your route and show you some "urban driving" MPG tips for that short route. Or, perhaps diamondlarry could do some MPG driving with you as well as he is near you. Either way you go, we are both 70+ MPG drivers, can't go wrong.

    Wayne
     
    #4 FireEngineer, Jul 9, 2007
  5. Highly ImPriused

    Highly ImPriused Impressive Member

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    This is a minor point, but how about walking the kid the 500 feet to the bus stop and then walk back and drive to work. I can't imagine it would add more than 5 minutes to your morning routine, would save a bit of gas every day, give you both a bit of exercise (maybe even have a foot race there?), and help teach the kid that he doesn't have to conform to the ways of the yuppie lemmings that he is surrounded by. Just a thought.
     
    #5 Highly ImPriused, Jul 9, 2007
  6. douglas001001

    douglas001001 smug doug

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    If you get scan gauge and an ev switch these are good places for use, especially in the morning drive.

    During warm up on those short distances, accelerate using ice for 1/3 of the distance, then flip on EV switch to shut off engine and glide to the next stopping point in zero arrow state. Then turn off ev to accelerate.

    I'll be driving through that way on friday and sunday, taking country roads (I'm going for an 750-800 mile tank), shoot me a pm if you want to join for part of the route to get some tips as I glide by.
     
    #6 douglas001001, Jul 9, 2007
  7. FireEngineer

    FireEngineer Active Member

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    <div class='quotetop'>QUOTE(douglas001001 @ Jul 9 2007, 10:28 AM) [snapback]475519[/snapback]</div>
    You have to go out in the country to do that!

    Just do it on your commute.

    [attachmentid=9548]

    [attachmentid=9551]

    Better yet, take a trip north this Saturday.

    Wayne
     

    Attached Files:

    #7 FireEngineer, Jul 9, 2007
  8. douglas001001

    douglas001001 smug doug

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    <div class='quotetop'>QUOTE(FireEngineer @ Jul 9 2007, 10:47 AM) [snapback]475527[/snapback]</div>

    I'm at 70.5 / 200 today, so I'll start the trip this weekend at about 300 miles. I only get 9 gallons in on a fill when last pip flashing. So I'll need 83.3 to get 750, I'll need 90+ for remainder of tank, 200 miles of country roads each way this weekend.
     
    #8 douglas001001, Jul 9, 2007
  9. Shorty

    Shorty New Member

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    I appreciate many of these comments. The EBH was on my list (my salesweenie had never heard of them, so I was going to order from metrotpn.com). And I'm hoping to get a Scangauge soon, and replace it with a custom data logger built around the ELK chip and an embedded linux box like the gumstix when time permits. I also completely understand the admonition to "just drive it" (to boil down chuck_k's post to three words), and often this will be the strategy. But engineers do like to optimize. The inner geek must be appeased. :p

    Thanks, all.


    Doc
     
    #9 Shorty, Jul 9, 2007
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