Hyper-miling


#1

I’ve come across a number of “tips” on line which would seem to improve mileage.



One that I’ve been intrigued by involved shutting the engine off if you’re going to be at stopped and idling for more than a certain time. The problem is how long you’d need to be stopped for this to be some benefit. I’ve seen posts which recommend if you going to be stopped for as little as 10 seconds to as long as 90.



Any insights on this?


#2

With a modern fuel injected engine, warm starting takes less fuel than maybe 10-20 seconds of idling. However, the amount of gas involved is fairly small, and you would more than make up for any savings in wear and tear on the starter and battery if you shut off the engine at every red light and stop sign. Not to mention the problems if the fails to start in the middle of the road for some reason.


#3

That’s a help.

I don’t shut everytime I stop, only if I know I’m going to be stopped in traffic for a while. Just trying to figure how long I’d need to be stopped to make it worthwhile. On those occasions, I try to to just coast and watch for the light to change. Fortunately, my commute only as a few lights that would keep me longer than 10 to 20 seconds. A couple of extra starts during the day shouldn’t cause that much wear and tear.


#4

Shutting engine off= no alternator, no power steering, no power brakes, etc. If you have your audio system on, that’ll take battery juice to keep it on–but not much. For anything under 90 seconds, ask yourself if it’s worth it. What about at night with lights on? Do your lights automatically go out when you turn the key off? How about the extra starts? How will that affect the life of your starter? How about the extra cycles that your fuel injected components go through, especially the fuel pump? And when do you start the engine? As soon as the lights in the cross section turn to yellow? Placing the gear shifter into idle is not a bad idea. It takes a whole heck of a lot less time to shift from neutral or park into drive (or first gear) than it does to start the engine, put the tranny in gear, then proceeding. Many vehicles won’t start unless the clutch is put to the floor or the tranny is in park. And what about possible “hot-heads” behind you who still don’t get it? HONK! HONK! HONK!, cussing, and possibly a case of “road rage” because you’re not immediately screaming down the road exactly as the light turns green. Just food for thought.


#5

You would not shut your engine off when stopped for even a few seconds here in AZ in the summer (you need full strength engine on AC) engine off would not cut it.Believe me you are happy to pay the cost,the heat is enough to cause poor behavior.


#6

It is a good idea for stops longer than one minute, such as when waiting for a train, traffic not moving at all due to an accident, or at a drive-up window. For shorter stops it simply isn’t worth it, saving but a few pennies while losing the A/C and audio.


#7

I don’t buy it. About half of the hypermiling stuff I’ve seen seems legitimate. You can save money by going the speed limit if you speed now. Paying attention to traffic flow so that you speed up and slow down as little as possible also makes sense, as dos accelerating slowly. Do Not Draft The Truck In Front Of You. You Will Die Really Soon If You Do. I’ve been hypermiling for several years and get better than EPA highway mileage during mostly commuting trips. It’s such a relieve that I have a name for it now! I think I’ll sign off, sit on the couch, and be be way too impressed with myself for a while…


#8

My Sienna gets around 24 mpg at around 70 mph, and at 65 mph when forced by speed limit to drive that speed already is up to around 26 mpg. One long stretch in Mexico has a speed limit around 50 mph, and I have never been able to estimate gas mileage because the gas gauge moves too slowly to tell. I would not be surprised if it gets 30 mpg at 50 steady. That sounds like a high number, but I remember renting a Buick Le Sabre to drive to Iowa after our old car got smashed in Austin, and it got well over 30 mpg at the mostly 70 mph speed limit.

But, when I am traveling long distance, I am traveling long distance. If I slow down to save gas, I end up with a $50 or $60 motel bill for an extra day of travel. So, I stick as close to the speed limit as I can, for maximum distance in one day rather than maximum gas mileage.

I certainly do not criticize those who work hard to conserve energy, if it trips their trigger. As prices go up, they will have company, and will be able to pass on tips when newbies ask for help, such as here. However, politically, I do not think government controls or taxation ever works as well as the market itself IN THE LONG RUN. Right now if the government implemented all sorts of draconian measures to reduce energy and carbon as many want it to, the economy will tank, and great R&D projects will be the first thing cut by the companies. Short-term gain; long-term disaster.

Some years ago, a brother decided to reduce heating costs in his house. He spent most of one winter with meters and graphs, and all sorts of work on the house to reduce air leakage and increase his R-factor. He got it so good when it was ten degrees F., and sunny, the furnace never came on all day. Then, he had serious problems once the house was sealed too tight, and was forced to spend more money to install ventilation. Plus he ignored his kids all winter. I paid the extra $40 a month and took my kid camping in the snow, heh, heh.


#9

Your comment on your friend’s house reminded me of a friend who bought a 175 year old farmhouse in rural NH some years back. All the windows on the north walls were minimal, and the south wall was all huge widows. All the trees to the south had been (and still were) cleared. The interior layout was designed to make the most of convection.

In the winter whenever the sun was out the heating system stayed off all day. With good modern insulation and vapor barrier, the passive solar heat could be retained and the result was amazing.

Properly designed, houses can use amazingly little generated heat and still be large and comfortable. We seem to have become so enamored with technology that we’ve forgotten the basics.