How are you making so many MPGs!?!

OK, now I am confused. I seem to hear a lot about Pulse & Glide (which might be a good name for a sex lubricant) where you purposely avoid a constant speed. The way I understand it (and I could be wrong) rather than driving a constant 60 MPH, you pulse up to 70 and glide down to 50 and repeat. It sounds dreadful and counter intuitive.

Today was my first 'long' trip in my 2010, about 130 miles. I drove with one passenger, a small dog, a full tank of gas, and had the AC on. I did not really go out of my way to do anything special and the trip odometer said I was getting 55.9 MPG. And this was through some hilly terrain, some 55 MPH highway, some 65 MPH highway and some dirt roads. I stayed within 5 miles of the speed limit, usually closer to the limit.

But in the future I have thought of some fuel saving ideas. Here are my top ten:

First, lose the passenger. There's 170 pounds of excess weight. He has legs;. he can walk.
2: Never fill the tank over the half way mark. 6 gallons of gas weighs close to 45 pounds.
3: Rip out the back seats. Having extra seats only encourages more passengers.
4: Do you know how much window glass weighs? Lose the windows and replace with Hefty bags and duct tape. If you do it right, it looks like limousine tinting.
5: Spare tire? Jack? Toss them out. How often do you get a flat tire anyway?
6: Reduce my body weight. I am going to schedule some liposuction and removal of my appendix, gall bladder, tonsils, and anything else I don't need. Also, do not consume any food or liquids 24 hours before you plan a trip. (If only 1 million people were 20 pounds overweight, it means that we are using fuel to move an extra 10,000 tons around everyday. Since we are an obese nation on the whole, think of the gas we use to ship blubber to work, shopping, schools, etc every day.)
7: Headlights rob power. Never turn them on. If you don't know where you are going after dark, you shouldn't be out in the first place.
8: Before dragging a heavy iPod into your vehicle, delete the songs you don't listen to much to make it lighter.
9: Keep your tires fully inflated...with helium.
10: Never brake. Sure, a few small children and some senior citizens might end up as speed bumps, but new children are born every day and young people will get old.

Good luck and happy motoring.

 

rite now im getting 45 mpg. and what i thought was becuz i ride on uphill/dowhill roads. im hoping once we move out i get a better gas mileage. *crossed fingers*

 

pulse and glide is the "best" way to eek out the mileage. but the OP only wanted to know how everyone got such great mileage and i do pulse and glide occasionally... but it probably amounts to less than 5-% of my driving and the reason is its really only effective at speeds of 45 mph and less.

its not convenient at freeway speeds, heavy traffic, etc. iow, its great if you have the opportunity to practice it and by all means do so, but there are other ways to get good mileage and for higher speeds, maintaining a constant speed is the way to do it.

also, take advantage of the terrain, building up a little extra speed on those gentle downslopes only to bleed that speed off slowly as you level out helps as well too.

the issues in getting good mileage is not driving a super efficient car (sure it helps!!) it is not fighting a losing battle against the laws of physics. wind resistance, inertia and momentum are all powerful forces that are constantly looking to sabotage your mileage.

case in point, get on the freeway, set CC and drive along, you will most likely settle out around 45 to 60 mpg... as your charge builds up, the battery will contribute a bit more and you will cruise along at 70 to 80 mpg for a minute, then settle back down to between 45 and 60 mpg.

now you will see wide swings when you change elevations (changes so slight that you dont feel the change) that is normal...

now, disable CC and take your foot off the gas until you have lost 5 mph... now speed up as gently as you can back to where you were. try not to go below say 30 mpg... can you do it?

nope...as you accelerate you will most likely be in the 10-25 mpg range. the reason is besides the above 4 forces of nature holding you back, you have the extra force of acceleration that has to be added to the equation.

now, dont get me wrong. pulse and glide is best way to get great gas mileage, but keep in mind, this kind of driving gets the best results driving between 25 and 40 mph. if you have the opportunity to drive at that speed and there is little traffic and multiple lanes and you have a little extra time and...

well, its like this, you can do " 5 and" driving, or you can just drive conservatively. driving conservatively should easily get you into the mid 50 mpg range. so it all depends on what you want to put into it

 

I'm going out on the road shortly, just removing seats now. Windows next but I consider glad wrap to be thinner and lighter than hefty bags, OK I lose the limo tint affect but hey, a few grams in weight can make all the difference. My bulimic friend showed me how to purge my stomach before I drive, that should get rid of all that useless bile I have been lugging about, a good dose of laxatives yesterday would have been a good move, oh well, there is always tomorrow.
Wish me luck everyone, 65mpg here we come!

Question; - When I run over a child or elderly person should I stop and back off them or continue driving until they wear down thin enough to roll out the back? I'm thinking drag versus momentum here.

 

Adding to the DaveinOlyWA's wonderful comments, please be aware there is a 46MPH(42MPH on 2G) barrier speed.
Above that speed, Prius becomes completely different animal, and the engine has to spin all the time.
Above that speed, it is very hard and painful to do pulse & glide, then we see very little or limited MPG gain.
Therefore, it is recommended to use CC during that speed, and slower speed is better for MPG number.

The real MPG gain by pulse & glide is accomplished below the barrier speed.

Ken@Japan

 

Don't forget to shed any unnecessary clothing. While local laws might frown on naked driving, (especially since you are not going for the limousine tint), nothing stops you from going commando. Men, iIf you are worried about chafing, apply a little Pulse 'n Glide brand lubricant down under as part of your daily routine.

Regarding the victims of your eco-friendly driving, I would recommend to keep driving. Unless they are clawing onto your bumper for dear life. I carry a lightweight snow brush to scrape them off. Don't feel bad about it; people are the ultimate renewable resource. Yes, I know the snowbrush adds weight, but without seats, passengers or a radio, the brush can become your friend and keep you company. If you style the bristles a bit and add a touch of makeup, you can probably use it to get into the HOV lane.

Speaking of dead things, remember that oil comes from once living creatures. Since God made life and God is pure, you can have faith that oil is pure so heavy filters are not required. Lose them. Every time you use an oil filter, the atheists win.

Once you start driving with the Hefty Bags or Glad Wrap, you will find you have enough natural ventilation that you can rip out the climate control system.

And if you are still confused about pulse and glide, have your bulimic friend help you out. I believe it is similar to binge and purge.

 

You have got to be joking!!!
Around here, anything under 20 mph over the limit will get you run over by a semi!!!!

Simple. Only drive downhill with a tailwind. Works with all cars, hybrid or no. Hell, I learned that 20 years ago, from the guys who used to measure MPG for the EPA!

 

All joking aside, (which is really hard for me), the country as a whole can save a lot of fuel by getting rid of the junk in most cars. I work with people that when we go out to lunch claim they can't drive because they have stuff in their cars and have no room for passengers. Or if they have to put a piece of equipment in their trunk, it is a 20 minute ordeal to rearrange the collection of items in there.
Oddly enough, these same people never seem to find room for a tire pressure gauge.

The other gas saving technique that I have not seen much conversation about is called 'driving less.' There are folks who have jobs or other situations that cause a lot of miles. But plenty of us (me included) make some trips that are either uneeded or inefficient or both.

When I was in high school 30 years ago <shudder>, you had to have special permission to drive to school and it was for special occasions, not everyday. Now the high schools in my suburban area have all built student parking lots. "Well Junior has to get to his job after school." Somehow I managed with a bike or walking. In the mean time, the gas-guzzling school buses still run around half empty.

And we train kids to be car-centric from an early age with electric toy cars. (Who remembers pedals?) I swear some of these children go from an electric scooter directly to a Rascal. (Which can be yours free if your Medicare approves it.) The only bright side is that as their legs atrophy from lack of use, it will be less weight to transport.

I was talking to a co-worker who had to leave a few minutes early to pick her son up...from cross country practice. Um, anyone else see a gap here?

 

Professor Julius Sumner-Miller once commented about when he was staying in a hotel in North Adelaide which overlooked part of the parklands around Adelaide which was used by the Australian Institute of Sport as a training grounds. He noticed that everyone arrived in a car, ran around on the grass for a while then left in a car. He assumed they were mostly going off to work or university in the city on the other side of the parklands. He didn't understand that behaviour.

 

I was thinking the same thing... instead of going back and forth from 50 to 70, why not just drive a constant 60? So I started thinking about this. 70mph, you are better off going a constant 60 because it will take you 15 to 20 seconds (or more) to [efficiently] accelerate from 50 to 70, yet if you take your foot off the gas, your car will quickly slow from 70 to 50 in very few seconds. The added wind resistance at 61,62,63,64,65,66,67,68,69,70mph will negate the "glide" benefits, and you would be better off just going a constant 60mph. However, if you are not on the highway/expressway/freeway, and you are pulse and gliding between 50 and zero (example) miles per hour and of course accelerating very slowly, then wind resistance will not outweigh your benefits from gliding.

note: although I clearly sensed the sarcasm/joking of your list of improvements, the flapping of the Hefty bags in the windows might actually create more drag force than weight-saving benefit. It would depend on whether you do more city or highway driving. When I was around 16yrs old (back in the day), my brother had a van for his first vehicle and I used to help him remove the 2nd and 3rd row bench seats and it took two of us because those seats weighed about 100 pounds each. The 0-60 acceleration improved very noticably when those seats were out of the vehicle; so I have been able to experience first-hand the benefits of removing seats from a vehicle. Of course, we can all experiment with this by comparing your cars 0-60 with driver only, versus having all four seats occupied by passengers. Yes, 0-60 is not fuel efficient; however, it is a great way to demonstrate the difference in vehicle performance when weight is added or subtracted. [/nerd]

 

It's all about tire pressure and not driving like a sh!thead

 

That is a bit simplistic. Weight counts for a lot. Which is supposedly why you can't get the SR in the V, to make the weight to get the mileage.

 

I think you've not got "efficiency" correct here. It's more like drive-train efficiency, not "keep the instantaneous MPG up" efficiency. I haven't seen times specified, but I've seen P&G in terms of accelerating at an indicated 15 MPG instantaneous, which you might be calling "inefficient". I haven't learned this technique yet, but I don't imagine it takes 20 seconds to go from low to high end of the band.

A band from 50-70 is probably high, due to wind resistance at 70, though.

 

A couple of points re: pulse & glide.

The theory of pulsing is to use the engine in an efficient (somewhat hard) way, then not use it all during the glide. Wind resistance does make this a PITA for little gain at freeway speed. But it is a powerful tool at lower speeds where wind resistance is a smaller factor.

Gliding is not coasting. Gliding requires a slight pedal pressure to negate the regen of a coast. When needing to lose speed, let completely off the pedal to capture some of the energy in the battery. For gliding, give just enough pedal to let it roll freely.

 

well I have basically tried to stop the "jack rabbit" starts. Not that I had a heavy foot before I bought my 2010 IV, but from time to time I'd like to "break away from the pack". I used to drive a 4 cyl Camry.
Anyway, I'm getting 48 to 50 just being a bit more conservative on my accelerations from dead stops. Also, I tend to be in stop and go traffic during most of my commute, so I'm using the battery big time.

 

You're right. Thank you for reminding me. We've been over this before. Since I drive a Corolla (with aspirations for a 2010 Prius), my experiences are based on my Corolla (43mpg is my best, with average of about 35mpg). I think of pulse and glide as coasting, but if the person who originally invented the phrase was referring to battery-assisted maintenance of constant speed with the engine off, then that is that. What is the maximum speed you can glide in a GenII and in a GenIII ? Thank you.

Wfolta, I could accelerate from 50 to 70 in my next door neighbors Porsche Turbo in about 1.5 sec, but I wouldn't be getting very good MPG. If you want to maintain good MPG, it will take you about 20 seconds to accelerate from 50 to 70 (that's one second per mpH). Try it on your way to work or on your way home today and let me know what your experience is. For extra credit, when you get to 70, take your foot 100% off the gas and see how long it takes to slow back to 50. I'm going to make myself a reminder note right now. I'll evaluate this also.

 

I've read several articles on it, and from what I understand you're not looking at it correctly. P&G is all about the efficiency of the engine. (It works in non-hybrids as well.) An engine is not most efficient when accelerating slowly, but rather in a particular band of load/RPM. The rest of the drivetrain has similar efficiency bands.

The Pulse phase is intended to gain speed at the vehicle's most efficient band, which may be faster than you imagine. The Glide phase is purely coasting. (In the Prius, you must press the accelerator slightly, to eliminate the artificial "engine braking" that Toyota has designed in when you lift your foot entirely off of the accelerator. People use the phrase "glide" to distinguish these two states; you're not actually using electric power*, but you are pushing on the accelerator slightly.)

I'll try it today to get actual numbers, but if I accelerate at 20 MPG for 8 seconds, then glide at 100 MPG for 8 seconds, I'm achieving something like 60 MPG. (It's more complex than that, I think, but.)

100% off of the gas will slow quickly because Toyota has added a fake engine braking (by regen) when you let off the gas entirely. So I would glide instead, and with a drag coefficient of 0.25 and low-resistance tires inflated to 40, it will go quite a lot farther than you think. (In fact, I am amazed how far I can glide at times.) The issue, of course, is 70 MPH: I believe wind resistance increases with the square of your speed, which is why P&G works best at speeds below 50 MPH. (That, plus 45 MPH is a magic number in the 2010 Prius because the gasoline engine will start spinning at that speed, even if it's off, in order to protect the electric motors from damage.)

Hopefully a P&G expert will chime in. I've just read about it and drive in traffic that really doesn't allow it on a long-term basis anyhow.

* Actually, it appears that you do use a small amount of electric power, I believe approximately twice as much as if you threw it into Neutral instead. This provides a light electrical boost.

 

Rybold: I don't drive on many flat roads, but I tried my best this morning on the way in, and gliding it takes me about 12 seconds to drop from 70 to 60. It should take longer to go from 60 to 50 (I wasn't going to try it in morning traffic), so I'd say we're talking zero gasoline usage for 25-30 seconds in a 70-50 glide.

I forgot to look at how long it takes me at 15-20 MPG to go from 60 to 70.

EDIT: I'll add it here instead of replying to myself again:

"When accelerating, the engine should be kept in the peak of the torque curve. A slow acceleration is less efficient." -- From a typermiling wiki.

That's acceleration from a stop, and it's a more complicated affair for a Prius, but I guess the point I'm trying to make is that you can accelerate too slowly in a mistaken belief that "really fast is bad, then really slow must be good".

 

Glide max without spinning ICE in D:
Gen II 41 mph
Gen III 45 mph