Another high mpg freeway trip, 257 miles at 51.9mpg

Discussion in 'Gen 2 Prius Technical Discussion' started by daveleeprius, Oct 15, 2007.

  1. daveleeprius

    daveleeprius Heh heh heh you think so?

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    I drove 257 miles yesterday, all freeway miles, at between 68-75mph and the MFD reported 51.9mpg at the end of the trip. My city milage is around 45mpg average.

    Anyone else notice that city milage isn't really higher than freeway milage?

    I drove with the cruise control on 95% of the time, set to 68mph. I did accelerate to 70mph and a couple of passes at 75mph, but most of the driving was done at 68mph.

    I drove over three mountain passes between 2500 feet and 3000 feet.

    Weather was clear, I didn't use air conditioning.

    I've yet to top that kind of milage driving around in the city, which usually has a lot of stop and go traffic, and doesn't get going faster than 35mph.

    The myth of higher city milage is still yet a myth, unless you define a city as a rambling road where you can cruise at 40mph for a sustained period of time.

    Here in the Seattle area, there are hills everywhere, and traffic is heavy most of the time.
     
  2. subarutoo

    subarutoo New Member

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    I commute 450 miles a week 99% freeway, and am right at 51.8 and have seen 52 several times. One night in bumper to bumper traffic in Las Vegas, I was able to max out the mpg bars in the MFD (99.9 mpg) over 1/2 hour of city crawling. Usually, my overall mileage drops when I exit the freeway.
     
  3. shumiron

    shumiron Junior Member

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    :lol:
    I intended to post an experience similar to this one with info on a 4,000+ road trip in Sept. The trip started in San Diego and went up the entire West coast around the Olympic Peninsula into British Columbia - Whistler - Central BC to Grand Forks - down to Couer d'Lane ID then hightailed it home down I-15 in two days. Total trip took 2 weeks and 3 days - averaged over 54 MPG for entire trip. Saw some 57 MPG on a couple tanks. Total fuel cost for over 4,000 miles was $220 with 2 tanks in BC at $1.10/liter.

    I do have a question though regarding travelling at speeds (65 - 80 mph) up long upgrades (in the mountains) where the drive train was revving pretty high on cruise control. The upgrade lasted for several miles and I felt uneasy listening to the chipmunks and lightning bugs working so hard under the hood. I did back off cruise and worked my way up at lower speeds - kind of semi pulse and glide.

    Was the extra precaution I took necessary, or could I have just let her rip up the hills in cruise? Is damaging the system possible by putting it under stress for extended periods?

    I had about 5,000 miles on the car when I started the trip.
     
  4. daveleeprius

    daveleeprius Heh heh heh you think so?

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    <div class='quotetop'>QUOTE(Shumiron @ Oct 15 2007, 03:58 PM) [snapback]526001[/snapback]</div>
    Good question. I noted the highest RPM on my Scanguage showed around 4200rpm, I think the engine max's out at 5,000rpm. I don't think it is bad for the engine to rev this high on a hill for several miles. After all, it's a Toyota engine, and from experience I've found most Toyota engines are rather bullet-proof and last for hundreds of thousands of miles.

    It's great to see other posts with the Prius getting so high milage on the freeway. But if I can get 52mpg on the freeway, according to Toyota, shouldn't I be able to get 60mpg in the city? I've never come close. I suppose if I drive very slowly and let people pass me I could come close. I tend to drive the speed of traffic though, and don't like people who are slow like that.

    Someone once said you should never drive so that your MPG is less than half your speed. Well, try driving the hills around the Seattle-Bellevue area (like go up Somerset in Bellevue) and you'll quickly see that this is impossible!!
     
  5. shumiron

    shumiron Junior Member

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    <div class='quotetop'>QUOTE(DaveLeePrius @ Oct 15 2007, 04:19 PM) [snapback]526014[/snapback]</div>
    We were in Seattle area for a couple days before heading North to Vancouver so I know what you mean. By the way we had perfect weather in Seattle - actually all the way around the West. 91 degrees at Cannon Beach Oregon at 6 PM. beautiful days in Seattle, too. We heard the rain came the day after we left Vancouver. Lucked out I guess. The trip down I 15 to San Diego was 1450 miles..so you can tell I was cookin' - 10 hour driving days.
     
  6. miscrms

    miscrms Plug Envious Member

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    <div class='quotetop'>QUOTE(DaveLeePrius @ Oct 15 2007, 04:19 PM) [snapback]526014[/snapback]</div>
    I think this is just simply a case where the car is smarter than you :lol: What I mean is, under cruise control, the car keeps everything pretty ideal. Around town, you and your right foot get involved. Getting good mileage in the city is not very hard, but it requires attention. I'm still learning, but definately notice the difference when I'm paying attention and when I'm not.

    We're not really talking about how fast you drive here, mostly just how you get up to speed and back down. I used to drive like a lot of other folks around here. Floor it off the red light, accelerate up to 10 over the speed limit, get 50' from the next red and brake hard down to 0. When you watch the MFD, you start to see how wasteful this is. I now accelerate more gently. If there are people behind me, I go just fast enough to accelerate with traffic. If there is no-one behind, I'll watch the instantaneous mpgs to limit my acceleration. Usually I'll try to keep it between 30-40mpgs when accelerating. I still accelerate up to 5-10 over, and just move with the flow of traffic. One interesting thing is to try letting up a little more than you think you should on the pedal while cruising. I often find the mpg reading around 45 while cruising, but if I let up a little it will go to 55 or better and still hold speed. I assume this is just putting a little less power to the battery. Slowing down is just a matter of watching ahead. If I think I may have to stop at the next light, I start gliding and slowly bleeding off speed. Hopefully by the time I get there the light will have changed, and if not I've racked up some high mpg time to help offset the upcoming acceleration.

    I still have a lot to learn, but there is a lot you can do to improve your city mileage w/o becoming a mobile road block.

    rob
     
  7. a priori

    a priori Canonus Curiosus

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    <div class='quotetop'>QUOTE(DaveLeePrius @ Oct 15 2007, 01:32 PM) [snapback]525927[/snapback]</div>
    This past month I had quite a bit of highway driving. The very best highway mileage I had was around 60 MPG. I was driving 65-75, most of the time with the A/C on. I slowed going up hills and sped up on the downhills. For the most part, I followed some semi tractor/trailers and kept pace with them. I may have gained from some wind blockage, but I think the main gain was dropping speed going up hills and gaining going down hills.

    Here is a photo I took during one stretch of this travel. I know it isn't a good idea to take pictures while you're driving, but this one shows the speed and the fact that the A/C is on. It just seemed to be a good day for decent speed and comfortable highway driving.
     

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  8. usbseawolf2000

    usbseawolf2000 HSD PhD

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    For those getting less city MPG than highway MPG @70MPH:

    At 70 MPH, you are loosing 57% (13.5 hp out of 23.7 hp) of the energy due to the air resistence. If you are getting lower MPG in the city @ average of 30 MPH, you are loosing 20% (1.1 hp out of 5.5 hp) of the energy due to the air resistence.

    The difference is 12.4 hp (surprise... surprise...) and you are loosing it through the brake pad despite of having regen braking! Look ahead and ease up on the acceleration and utilize more regen braking.... Well, you paid for it as a package... use it more.
     
  9. Tideland Prius

    Tideland Prius Moderator of the North
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    <div class='quotetop'>QUOTE(a priori @ Oct 15 2007, 07:13 PM) [snapback]526138[/snapback]</div>
    normally I would look at the mpg and congratulate you. This time, I'm looking at the picture quality and wondering what camera you used. It's crystal clear!
     
  10. a priori

    a priori Canonus Curiosus

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    <div class='quotetop'>QUOTE(Tideland Prius @ Oct 15 2007, 11:39 PM) [snapback]526192[/snapback]</div>
    I'll try to say thanks, anyway. :unsure:

    The camera is a Fuji point-and-shoot digital. I even forget the number. It is about three years old and shoots at 6 Meg. It is clear in a moving car mainly because it has such a fast shutter speed. It was, far and away, the fastest shutter speed of any non-SLR digital camera. It also helps that it was a bright day.

    You'll notice that the car was on a downhill when I took the picture. The instantaneous MPG is nearly pegged even with the speed at 70 and the A/C on. It really was a beautiful drive through West-Central Wisconsin and up the Misissippi River to the Twin Cities.
     
  11. sea-horsea

    sea-horsea Junior Member

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    <div class='quotetop'>QUOTE(a priori @ Oct 16 2007, 01:18 AM) [snapback]526225[/snapback]</div>

    so can you find out the model for the camera? its really nice from a point and shoot cam...what resolution you had it at? thanks
     
  12. Danny Hamilton

    Danny Hamilton Active Member

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    <div class='quotetop'>QUOTE(DaveLeePrius @ Oct 15 2007, 01:32 PM) [snapback]525927[/snapback]</div>
    Actually, that sounds pretty close to how the EPA defines city driving. I guess that's why the EPA milage is higher for "City" than "Hwy". It sounds like your highway numbers are pretty close to what the EPA states.

    <div class='quotetop'>QUOTE(DaveLeePrius @ Oct 15 2007, 04:19 PM) [snapback]526014[/snapback]</div>
    You mean according to the U.S. EPA right? Those are numbers that the EPA assigns to the car after they test it. Those numbers don't originate with Toyota. And yes, if you drive the car exactly like the EPA test, then you should be able to get 60 mpg. If you are getting less, then your particular routes and driving style must differ from the U.S. EPA test.
     
  13. a priori

    a priori Canonus Curiosus

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    <div class='quotetop'>QUOTE(sea-horsea @ Oct 16 2007, 02:04 AM) [snapback]526235[/snapback]</div>
    I found some info on this old camera. It really isn't anything special, except that it has a very fast shutter speed. The model is a Fuji FinePix E550. It is a sturdy camera that uses two AA batteries. Easy to get cheap rechargeables for it, and you can always buy AA batteries if your rechargeables peter out.

    It has 6.3 million pixels resolution (that's what I shot the picture at), and the lens is a 4x optical. The nice thing is that it can really replicate a standard 35 millimeter SLR, because the lens is similar to a 32 - 130 mm zoom.

    I think you can get the same type of cameral now for probably one third of what I paid 30 months ago!

    Here's a link to an older site that described the camera when it was introduced.

    Since you asked . . . here are a couple of other photos that I've taken with this camera:
     

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  14. Bob64

    Bob64 Sapphire of the Blue Sky

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    Wow that is an amazing camera.

    I think in stop and go rush-hour traffic, the breaking factor for me is if it is uphill, which can be as bad as 25mpg... but luckly this is only for very small sections of my trip.

    If it is uphill, there is really no way to get any decent gas mileage unless you wanna drain your battery all the way down with an ev switch.

    On flat/downhill sections of highway/city rushhour traffic, I can manage 80mpg, assuming the max speed is less then 40mph, and that there arn't huge high-speed sections followed by a sudden section (that is out of sight/prediction range) where traffic is stopped and I'm forced to brake.

    On completely flat highway sections, you can also try "super-highway-mode" for ~75mpg at 55mph.
     
  15. hill

    hill High Fiber Member

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  16. a priori

    a priori Canonus Curiosus

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    <div class='quotetop'>QUOTE(hill @ Oct 16 2007, 01:27 PM) [snapback]526460[/snapback]</div>
    I know it's pretty bad. Thankfully, you can take pictures like this without even looking! I just set it for wide-angle, reached over and snapped the photo. Of course, I had to take many to get one that worked! What you see is a cropped picture -- the original isn't very impressive.

    Also, the 70mph was on a level-to-downhill run with no traffic nearby. Maybe it isn't the safest thing in the world, but it took less concentration than trying to find a new radio station!
     
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