1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Non-Prius gas saving technique

Discussion in 'Gen 2 Prius Fuel Economy' started by dwreed3rd, Jul 25, 2008.

  1. dwreed3rd

    dwreed3rd New Member

    Joined:
    May 13, 2008
    742
    4
    0
    Location:
    Marietta, Ga
    Vehicle:
    2008 Prius
    Did not want to cluttler the Prius threads!
    If you’re only interested in Prius fuel savings, you may want to skip this post. The following information does not apply to the Prius and, in fact, would have the opposite affect on Prius gas mileage. However, since many members also have non-hybrids and some specifically Avalon’s, I thought that I would share my findings. I’m sure that some of you are already aware of the following information, but for those that aren‘t, here goes. I’m also fairly sure that the Avalon isn’t the only car that works this way.
    I have been using our ScangaugeII on our 2000 Avalon XLT w/108k miles, for some time, while waiting for our Prius. I found the GPH & HPR gauges particularly enlightening and thought that I would share my findings. The metro Atlanta topography is rather hilly, with very few, long, level, stretches. On the down hills, I tend to disengage overdrive and/or drop it down to “2†(automatic), before applying the brakes, to keep from gaining speed. Before ScangaugeII, I noticed that on medium to long, down hill runs, the Avalon’s trip computer would max out at 99.9 MPG. This was whether overdrive was engaged or not. I assumed that this meant that the engine was basically getting the least amount of fuel and therefore the maximum MPG. The ScangaugeII revealed that this was only partially true. With overdrive engaged, the car must be freewheeling. The GPH & HPR gauges would level out at their normal idle readings. I interpret this as meaning the forward motion of the car is not spinning the engine and that the engine needs to use fuel to run the fan belt to charge the battery, run the A/C, power brakes, power steering, water pump, ETC. However, when I disengage the OD and/or drop it into “2†, the GPH & HPR gauges both drop to 00.0, meaning no fuel. The transmission is spinning the engine fast enough to power the accessories. The injectors are shut down and you are not using any fuel. Therefore, after several weeks of experimenting we are now enjoying a ~2 MPG improvement in our gas mileage, around town. The OD button is on the Shifter and is easily engaged or disengaged for down hill when drifting above the speed I want to maintain. Shifting out of OD and/or into “2†also saves on brakes. The engine will be spinning in either case, unlike the Prius unless in “B†mode. Shifting in and out of OD is smooth, all the way up to posted limits and I don’t drop into “2†above 30mph which is also smooth. Drive “2†also makes for better control and handling on some of the hilly winding 25mph ess curves in the metro Atlanta area. Again, I just though that I would share my findings in case some of you may be able to take advantage of it. We are experiencing a ~2 MPG improvement in gas mileage as a result. We were getting 17-19 MPG around town and now getting 19-21. Haven’t made a trip lately. Highway has been 24-26 in the past. I though that I always knew how to get the good gas mileage, not that I always drove that way, but usually. This is not a paid ad, but the ScangaugeII will definitely pay for itself at the pumps, for us anyway. I hope you find this helpful.
     
  2. dwreed3rd

    dwreed3rd New Member

    Joined:
    May 13, 2008
    742
    4
    0
    Location:
    Marietta, Ga
    Vehicle:
    2008 Prius
    Just a quick update. It reminds me a little of the Glide portion of the Pulse and Glide technique for the Prius, about which i've been reading. Of course it depends on the route, but I've been able to bring our 17-21 mpg up to 25+ mpg on some of our hillier routes, around town. It will probably also save some fuel driving up I-85 to Martinsville, VA. in October, if we still don't have our Prius. It takes a little practice, like I hear the pulse and glide does, but we're averaging a ~2 mpg, or ~10%, increase, from tank to tank. Don't know how you can tell w/o a GPH or HPR, gauge but if you drive an automatic with OD, it may also work on your non-hybrid. GPH & HPR gauges drop from average idle, 0.45GPH & 7.5HPR, to 00.0GPH & 000.0HPR. You are not using any fuel as on the downhill with OD disengaged. You want to use OD on the level and uphill to save fuel, but disengage it going downhill if you can maintain speed w/o using the accelerator. Perhaps if any PC members have experienced this, they can share their year/make/model with the other members that don't have a scanguage. If you know that OD in your car works that way and have a tach but not a scangauge, note your Rpm @ idle. Coasting on a downhill, when you see the tach drop to idle RPM your are probably freewheeling and the injectors are probably suppling fuel to the engine to maintain idle. If you disengage OD you will see the RPM jump to the normal RPM you would expect to see at that speed on a level road with OD disengaged. This may be more than some drives want to deal with, but it really easy to use. Just thought that sharing this might help a few PC members to save a few bucks at the pump.
     
  3. dwreed3rd

    dwreed3rd New Member

    Joined:
    May 13, 2008
    742
    4
    0
    Location:
    Marietta, Ga
    Vehicle:
    2008 Prius
    O.K. I didn't expect a ton of responses, but I see from the profiles that I'm not the only non-prius owner out there. I guess I must assume that I was the only one left that had no idea of how OD worked. I told my son about it. He drives a 2000 Maxima. His, unlike the Avalon, will automatically turn off the injectors without coming out of OD, but he has to let his foot completely off of the gas, which he did not realize. Sorry, he borrowed my SGII and is now registering improved MPG as a result of knowing when to let off of the gas so that the injectors will shut down, resulting in 00.0 GPH & 00.0 HPR for the downhill situations. He didn't know that it made a difference to completely get off of the gas.
    I was just wondering if the title for the thread was confusing, noboby cares if it's not a Prius that you can save gas on, that other members think I'm full of baloney, or just that everyone already knew this. I just can't believe that I did not get at least one reply. If I'm totally smoking bad weed I need to know! Otherwise the monitors can kill this thread. I know that it depends on terrain, but I just thought that others, if previously unaware, would want to save ~10% fuel costs on their non-hybrids also.
    Aside to DaveinOlyWA: If you read, this it's my vent!