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Money saved on gas with Prius

Discussion in 'Gen 3 Prius Fuel Economy' started by cycledrum, Feb 1, 2011.

  1. walter Lee

    walter Lee Hypermiling Padawan

    Joined:
    Oct 26, 2009
    1,126
    376
    5
    Location:
    Maryland
    Vehicle:
    2010 Prius
    Model:
    III
    I'm getting about 59 mpg for the last 12750 miles on my 2010 Prius III.
    My previous car was a 1990 Accord LX which got 21 mpg in the city
    and 32 mpg on the superhighway - when I first purchased the
    Accord it got about 23 mpg in the city and about 32 mpg on the highway
    but over the years the cylinders were wearing out and
    I lost some compression/power over the years.
    I have a tendency to keep my cars over 10 years.

    I've been trying to learn how to maximize the MPG on the Prius for over 12 months.

    To get the best MPG on a Prius -

    1) Engine coolant temperature (Fwt) - during the winter when the temperature drops below 40 F - for short trips or stop and go travelling - IF the driver manages to keep the coolant temperature above 130 F rather than have the ECU automatically run the ICE THEN the driver can usually keep the winter MPG over 50 MPG if he also does grill blocking. For non-stop long trips, grill blocking is not necessary and monitoring the FWT is not necessary even in the winter because constantly running the ICE will insure that the coolant temperature be satisfactorily high enough. The ScanguageII XGAUGE for the engine coolant temperature is FWT/CWT.


    2) State of Charge (SoC) - The HSI SoC bar chart indicator only show the Prius Traction Battery levels from 70%(top bar) to 30% (bottom bar). At somewhere around the third to fourth bar from the bottom the battery is at about 50% charge level. Somewhere from 46% to 40% depending on a variety of conditions (third to second bar from the bottom of the HSI Soc bar chart) the Prius will automatically turn on its gas engine to aggressively recharge the battery up to 50% with a loss of 3 mpg to 6 mpg in 3 minutes. To get the best MPG - a driver must not allow the Prius to automatically recharge the Traction battery - this means increasing the Pulsing of the engine during a Pulse and Glide hypermiling session or using the regenerative braking system to recharge the engines when the SoC drops below 50%. The SoC programmable XGAUGE on the ScangaugeII is a more precise permenant display than the HSI SoC bar chart.


    3) gallons per hour (GPH) vs miles per hour (MPH) - this tells the driver when the Prius is coasting with the engine off ( 0.02 GPH) and also can indicate the power level the ICE is running at ( 15kw estimated = 1.25 GPH) as well as instantenous MPG ( MPH/GPH = MPG). GPH also can show the power requirements for a section of road for a particular velocity, e.g. for the same section of road but just going in different directions.... 30 mph@ 1.4 GPH going uphill and 30 mph @0.50 GPH going downhill. It is this particular display that tells the driver the most obvious truth - its more fuel efficient to accelerate on a downhill grade than it is to accelerate up to speed on a flat or uphill grade. Less gravitational forces means less torque is required to reach a particular velocity hence the cost of energy is less for moving the same mass. The scangaugeII XGAUGE for gallons per hour is GPH.


    4) A tire gauge (Psi) - to get the best MPG on the Prius you need to set the tires to the maximum pressure as designated by the tire manufacture on the sidewall of the tire for a
    Yokohama Avid S33 that is 44 psi cold. By setting the tire pressure to the maximum psi - the tire's rolling resistance is lowered and it will extend the possible distance a Prius can coast/glide without using fuel or electricity. Tire pressure will vary depending on the outside temperature and whether the tire is cold (not driven in the last 2 hours) or hot (recently driven tires). Maxing out the tire's Psi increases the Prius MPG when driving non-stop or when the Prius is gently de-accelerate to a stop.


    5) The clock(time) - giving yourself enough time to get to your destination allows you to drive slower. The option to driving slowly allows for gentle accelerations, coasting/gliding
    to a stop, timing the speed of the Prius with the traffic lights so you don't have to come to a complete stop, and avoiding speeding over 53 mph. All good things when working to increase any motor vehicle's fuel efficiency. Selecting a time when there are few or no other vehicles on the road also gives the driver to option to use other hypermiling techniques without obstructing traffic.


    6) Maps/Route Planning/GPS unit - some routes due to traffic, road surfaces, traffic signals/controls, events beyond your control, construction or topographical characteristics will offer or have the potential for better fuel efficient than others. My personal experience is that different driving route from the same starting and destination points can have significant impact on any car's MPG
     
    3 people like this.
  2. adamace1

    adamace1 Senior Member

    Joined:
    Jun 22, 2009
    1,403
    191
    0
    Location:
    Charlotte, NC
    Vehicle:
    2010 Prius
    Model:
    II
    41,000 miles for me

    51 mpg in my prius vs 23 mpg in my car i traded in. 3.30 for gas.

    994 gallon difference so in two year i saved over 1,000 gallons of gas and $3479. so if i have the car ten years i should save $17,395!!!!!

    if every american did this we would save 452,054,749 gallons A DAY!!!!!!!!!!!!!!!!!!!!!
     
  3. M D

    M D No more gas guzzler :D

    Joined:
    Nov 18, 2010
    66
    16
    0
    Location:
    DE
    Vehicle:
    2010 Prius
    Model:
    V
    Only 5,000 miles for me. Averaging 46 mpg vs. 14mpg in the BMW I traded.

    BMW ran on premium vs. regular for the Prius.

    Averaged cost-per-gallon at $3.50 regular and $3.80 premium since November when I made the trade.

    So, I've saved $976.71 and 248.45 gallons of gas.

    In the interests of full disclosure, my car payment has gone up $32/month - so an extra $224 there. But my insurance premium went down $20/month, so that's $140 back.

    That's still nearly $800 saved over 7-months though, which certainly isn't to be sneezed at.

    I also saved $2,000 by not having to fork out for new tires for the Bimmer, two of which were punctured (but still drove, being run-flats) and the other two only had around 2,000 miles left in them.
     
  4. tomlouie

    tomlouie Member

    Joined:
    Mar 26, 2011
    118
    21
    0
    Location:
    Boston, MA, USA
    Vehicle:
    2010 Prius
    Model:
    II
    I won't bother posting numbers, because as other have said, the calculations all depend on your personal situation. For us, we do a lot of short trips in city traffic, so the fact that the Gen3 Prius gets great city mileage helped sway the decision when compared to the city mileage of other cars.
     
  5. Zorba

    Zorba New Member

    Joined:
    May 3, 2011
    16
    2
    0
    Location:
    Michigan
    Vehicle:
    2011 Prius
    Model:
    IV
    I drive a lot doing consulting work. My first month with my Prius I drove 6,500 mi. My last vehicle, a Toyota Tacoma, got a combined 23 mpg. I don't drive special for mileage, but I ave. over 54 mpg this first month. Compared to the Tacoma, I saved $640 this month alone. This was an extraordinary month. Most months I'll drive around 3,000. So, my normal savings will be around 3,600 miles and my savings will be approximately $360 a month.

    That will add up nicely over the life of the car. My last two cars have lasted me 8 years each. At that rate, I'll save about $34,560.

    I know that's driving the Prius 345,600 mi. over 8 years. The Prius is a miracle car. I believe it will make it.

    Z
     
  6. mgb4tim

    mgb4tim Noob

    Joined:
    Jul 8, 2009
    1,153
    111
    9
    Location:
    Pittsburgh, PA
    Vehicle:
    2010 Prius
    Model:
    III
    I've tracked my fill-ups with Fuelly.com.

    My old Cadillac would have used $6,070, versus the $2,560 I spent with the Prius on the 38,000 miles I've driven the Prius over the past 2 years. I've saved $3,510 in gas alone. The 8-quart oil changes, I don't even want to talk about that.
     
  7. jjcgolf72

    jjcgolf72 New Member

    Joined:
    Apr 21, 2011
    7
    0
    0
    Location:
    Chicago, IL
    Vehicle:
    2010 Prius
    Model:
    III
    So far 5 fillups saving = $383 over toyota 4 runner 15mpg. I am avg 50.5 for the 2000 miles since owning car.