Discussion in 'Gen III 2010+ Prius Fuel Economy' started by F8L, Jul 25, 2012.
wow you guys are all doing great. love these type of threads.
And then there should be a test to make sure you haven't been drinking:
The Man With Two Brains -- drunk test is hard -- Better Quality - YouTube
I want to learn how you guys are getting 60 in a Gen 3.. could extend my own mileage on my PIP.
If you are doing freeway driving it is as easy as slowing down to 60mph or less and using glides or Warp Stealth at every off ramp and overpasses/hills. At 60mph your steady mpg should be 60-65mpg on a flat surface with no wind, rain and temps above 60F. So tossing in smart driving when off the freeway will push mpg even higher. If you get really good at gliding and or have a really good commute you may be able to bring your freeway speed up to 65mph and still be in the 60mpg area but higher speeds make this harder to achieve.
a hypermiling PiP should get about 100-150 mpg combine or 6-8 miles per kilowatt hours charge.
city/urban driving environment: 1. driving without brakes - timing your vehicle with the traffic lights so the Prius never really stops and you use the brakes infrequently. You can tell when a stop light is about to change from green to red by looking at the pedestrian count down timers and the traffic light ahead of the traffic light immediate to you. Even if you can not see the state of next traffic light ahead of you, you tell you have a red traffic light or there's traffic jam infront of you if the vehicles in front of you all have their brake lights on or if the vehicles on a road that intersects with your that is in front of your lane/road has vehicles moving very fast or if they are stop/waiting for a green light. 2. Keeping the Prius top speed under 35 mph optimizes your fuel efficiency by keeping aerodynamic drag energy losses to a minimum - this should extend the all electric motor range . 3. Pulse and Glide - on flat road like in Los Angeles CA - accelerate the Prius up to 30 to 35 mph (using either electric or gas motors - avoid going into the HSI power/red mode though) then pull back the accelerator so that Prius is not using the gas engine and barely using electric power ( don't allow the HSI display to go into RCHG mode) - allow the Prius speed to drop about 10 mph to about 20 to 25 mph then repeat. 4. Lower your vehicles rolling resistances to increase the gliding/coasting distances of a pulse and glide by increasing your tire pressure to about 4 psi below the maximum side wall tire pressure. 5. Grill blocking - when the outside driving temperature drops below 60 Fahrenheit degrees, block the front air intake so the engine warms up faster and stays warmer in the cold. 6. Design your commuting route to be energy efficent - avoid routes that require you to stop or that suck out energy/momentum. this means avoiding stop signs, speed bumps, rumble strips, road construction, times/lanes when there are bus pickup-drop off, times/lanes for garabage pickups, and soforth. Select roads where there are two lanes or more so that vehicles can easily pass you by if they want to go faster. 7. Time shift - schedule your trips when there is less or no traffic on the roads you are taking. This makes it easier to do techniques #1, #2, and #3. 8. keep your vehicle as light weight as possible. 9. At speeds under 40 mph don't use the AC- if its too hot then roll down the window instead but otherwise keep the windows rolled up for less aerodynamic drag energy losses . 10. In hilly terrain - it is more energy efficient to accelerate while going downhill than it is to accelerate going uphill. 11. Use 100% real gas instead of gasohol/10% ethanol gas. 100% real gas is not available in metro areas like Los Angeles unless you can find gas station at a marina/seaport (which is exempt). 12. Keep the tranny in "D" mode don't use "B" mode.
for a PiP only: if you use only electric power and you recharge your batteries regularly - keep your fuel tank only a 1/4 full ( about 3 gallons of gas). Each gallon of gas is 7 pounds. A full tank of gas is about 77 pounds. The weight of the fuel tank increases the weight on the rear wheel axle and increasing the rolling resistance on the rear wheels/tires. A fuel tank that is near empty should help you extend the glide phase in an all electric pulse and glide cycle.
It's good to see that you guys are still trying to obtain the best MPG you possibly can. I recently took a 420 mile round trip to San Diego, DRCC and AC all the way down and back. I was surprised to have gotten 62mpg. The left over gas allow me to drive another week and a half. Overall was 650 miles on 10.7gal. I'm happy with the mileage but don't think I will actively trying to get good mileage from now on. I'm just gonna get in and drive.
Walter's list is pretty comprehensive. The only nit I will pick has to do with the advice to stay below 35 mph in the city. While true per se, speeds up to 45 mph add very little extra drag and are much better tolerated by the driver and other cars nearby.
His post might make it sound like 60 mpg in non-highway driving requires extreme measures. This is not true at all. 80 mpg requires extreme measures. I'll try to write more later, but I think readers would benefit from a list that prioritizes those aspects of driving that are 80% of hypermiling's best for 20% of effort.
Hint #1: P&G, minimize brakes, avoid short trips by themselves
Hint #2: coast
Hint #3: coast
Disclaimer: I am no Wayne Gerdes, but outside of our cold winters I average 55 - 60 mpg in highway driving and 70+ mpg in my city driving in a Lexus CTh.
I agree with sagebrush.
I will add I had a 2005 Pruis II for seven years, what I found is that on 45 mph roads I got my best gas mileage at 39 mph or at about 52 mph, to me the car seemed to drag or lug down aroud 45 mph, it just seemed more free at the other speeds YMMV.
Chesleyn moniker says he has a Plug-in Prius (PiP) and drives in Los Angles - I thought 60 mpg was sort of a low standard for a PiP which should get about 75 mpg without breaking a sweat - even if one is caught in traffic jams in a heat wave or speeding along on the LA super highway. Okay - I went a bit extreme on the aerodyanmic drag - 60 mpg is a fairly low standard and you could get by with 45 mph, too. And yes - On a good summer's day a Prius can get +70 mpg on a commute ( e.g. today I got 84 mpg to work and 74.mpg from work in my commute) However, on a bad day it might drop to 55 mpg or 60 mpg or even lower (e.g. I got 55 mpg to work and 22 mpg from work on one winter's day commute). I find that even as a skilled hypermiler in the summer time - that keeping the overall FE over 65 mpg requires work and keeping the Prius' overall FE over 70 mpg requires serious effort. In addition, using a regular 3rd gen Prius for too many short trips or driving too often in very bad weather will cause the Prius' overall mpg to drop. The advantage of a Pip is that it can use electrical power for those few short trips and prevent the overall mpg number from dropping.
walter -- on my commute to teach I stay off the freeway. This boosts my MPG way up. But if I'm going to the west side or have the other 1/2 in the car with me… well I'm screwed. I get about 60-70 mpg.
Sagebrush is correct in that aggressively coasting/gliding is the simplest and easiest way to improve the any Prius' fuel efficiency. However, I would like to stress that the Prius will coast longer distances if your speeds closer to 35 mph and if your tires are over inflated by about 7 psi over the recommended settings as listed on your door frame/jam. Picking long stretches of open roads with very smooth asphalt surfaces with no stop signs or speed bumps also helps, too. With respect to other people on the road - if you shift your travel times to when there are less vehicles on the road - you'll find hypermiling is not only easier but will return better fuel efficiency as well.
In the next posting you'll see a failed effort to get 99.9 mpg via time shifting.
It's still pretty high at 85 mpg. Note that the tank only has .7 gallons left - that's because this particular trip is part of an effort to get a 800 mile tank - which is currently at 739.9 miles.
Time Shift enhanced Hypermiling ( avoiding rush hour)I travelled the same 15.8 mile commute I normally do to work ( which has an elevation drop from 500 feet above sea level to 300 feet above sea level) but I did it when most of the traffic lights (4am to 5am) are blinking yellow so I don't have to stop at all. My 2010 Toyota Prius III's stock Yokohama Avid S33 tire pressure is set 48 psi front 46 psi rear is unchanged. My average speed jump up from 17 mph to 26 mph because my time sitting in front of the traffic lights is near zilch. I was hoping to get + 99.9 mpg but instead I just got 85 mpg. Normally, the ScangaugeII AVG estimates that I get about 75 mpg on this commute trip/route during rush hour so a 4.5 mpg improvement is not all that impressive.
I have a SG2 also. What does TPS and Flv stand for? I'm using SoC, IGN, and ℉WT
Nice! The stop lights blinking yellow has to be huge, especially when combined with little to no traffic.
I would agree with that! Think of all the pulse and glide goodness that could happen with that.
Walter, what is the speed limit on the road? How much traffic is out at that time of day?
TPS(top dead center)=19/IGN(ignition)=22 is for approximating super highway mode
FLv= fuel left in gallons
The speed limit varies from 25 mph to 50 mph but hardly anyone is on the road. My target top speed for SHM was 30-35 mph. My commute route is mainly two-lanes to four lanes so anyone can pass me by. There were a few blinking red traffic lights that I had to stop at but most of the traffic lights wer blinking yellow- so I could breeze right through without stopping a P&G cycle (40-30 mph, 35-25 mph)! I didn't accelerate hard enough on the downhills (top speed 45mph downhill, low speed 28 mph top of hill) for some DWL cycles and that's why I think the trip overall mpg never broke pass the 90 mpg range. At the +70 mpg range - if I make one mistake the Prius will lose t several mpg for that trip.
Walter, TPS is throttle position.
The harsh reality of hypermiling......
Separate names with a comma.