Hyper-Miling Posted by: Adam Fuson @ 2008.01.30.0024
Last June Bull posted some links on decavirate about affecting a car's efficiency through driving style. I have been improving the energy efficiency of the house for the past few years and so it seemed reasonable to investigate improvements in energy efficiency one could make in transportation. For an entire tank of gas I was diligent to not accelerate aggressively keeping the rpm under 2000. I let the car coast down hills - sometimes with the engine running sometimes not. Obviously, you must be careful when coasting downhill without the engine running. Power steering will not be active and power brakes will soon fade. Additionally, your car may not always start exactly when you want it to or on the first attempt.
However, thinking ahead for changes it topography and traffic controls enabled me to soar to 35 mpg from an average 27-28 mpg. I had thought that driving style might not make a very noticeable difference, but it can definitely mean 25% increases in efficiency. Obviously, the value is not in one tank, as the cost of driving is not in one tank of fuel. But saving even $8 per week could mean $400 per year. Larger vehicles should realize an even greater savings in comparison to my Acura, but killing the engine while moving may be much more difficult to do while driving a Suburban or something of that size. In general, driving and accelerating more slowly may save fuel and wear on your vehicle, though engine efficiency will also have an impact on your economy. Finally, in order to plan ahead and have room to avoid braking, one finds himself leaving larger gaps in traffic, which also tends to allow traffic to flow more smoothly. So while you may want to drive as fast as possible when the road is clear, when there is traffic, let a seemingly unreasonable gap of 100+ feet open and enjoy the benefits of spending less on fuel, increasing the average speed of the traffic, and reducing the wear on your vehicle and clutch leg. Any other driving tips, Grandpa Joe?
I've seen a lot of different things about the accelerating quickly versus not. I'm not an engineer and don't have hard numbers, but I think the key is to balance between throttle open more for a short time, versus open less for a longer time. To be effective, from what I've read previously, you are going to be accelerating very, very slowly to see any benefit.
It should be noted, too, that a lot of cars fully cut the fuel supply when you lift off the throttle. Gas usage has as much or more to do with throttle position as it does with RPM. By turning the car off/putting it in neutral, you might see some benefit of no engine braking at most.
Personally, I don't see the savings balancing out the wear and tear it could potentially cause to my transmission and engine.
As a side note, it looks like I may have gained 4-5 MPG by removing my roof rack for the winter (and getting a smaller engine).
well, you are right about throttle position, I would say, but rpm is closely related to throttle position. and engine braking doesn't help mileage, nor does sitting at light or signs with an idling engine. I bet the bull could come up with a way to store all the energy in caps or batteries that would beat any hybrid available, though it would probably have the comfort of a super tub and so you'd feel like you were in a street luge all the time
I'd love it, I'm sure... should I add that to the wiki, Bull?
Charlie, Fuse will try to convince you that the car is still buring gas when you are moving in gear and let off the throttle. I had this argument with him when we discussed whether you would save gas by shifting to neutral (or clutching) when going down hill or by staying in gear. Fuse, rpm and throttle position are not directly related. I can run my car upto 7000 rpm while only using 1/8th throttle, where as I can do the same at full throttle.
I did this, not quite to the extent Fuse did with the engine shut-off unless there were very large hills, 471, and 275 going to and from the bike shop. I went from 22.5 mpg to 29 mpg. Instead of shifting at 6500 rpm I'd shift at 2500 rpm. With that being said, I saved gas and could still take Bremer any day of the week in a race. Fuse you might also want to add that you shouldn't use your E-brake for braking when the engine is off, it doesn't activate brakelights.
Fuse does not care if the brakelights don't activate. The less they are used the less often they need to be replaced. Screw safety or sitting in the middle of an intersection because your car would not start.
Another note regarding RPM does not equal fuel consumption- my 5-series got better gas mileage going 80 that 60 in fifth gear. Higher RPM, just that the engine was more efficient at that RPM. Once the engine reached that RPM, it took less to maintain it.
In general, driving and accelerating more slowly may save fuel and wear on your vehicle, though engine efficiency will also have an impact on your economy. - I agree, Charlie.
Bremer, I don't see how this would necessarily lead to one sitting in the middle of an intersection. You still have control of your vehicle and the ability to pay attention to driving. Plenty of soccer moms and suburbanites do that perfectly well on their own just by not paying attention. "Oops, did the light just turn red, and I have no where to go?"
Mitt Romney "attended Brigham Young University, where he graduated as valedictorian, earning his Bachelor of Arts degree summa cum laude in 1971.In 1975, Romney graduated from a joint Juris Doctor/Master of Business Administration program coordinated between Harvard Law School and Harvard Business School. He graduated cum laude from the law school and was named a Baker Scholar for graduating in the top five percent of his business school class."
Mike Huckabee "graduated magna cum laude from Ouachita Baptist University, completing his bachelor's degree in Religion in 2 1/2 years before attending Southwestern Baptist Theological Seminary in Fort Worth, Texas, where he dropped out after one year. He has two honorary doctoral degrees: a Doctor of Humane Letters, received from John Brown University in 1991, and a Doctor of Laws from Ouachita Baptist University in 1992."
Hilary Clinton "graduated [from Wellesley College in 1969] with departmental honors in political science. Stemming from the demands of some students, she became the first student in Wellesley College history to deliver their commencement address. She received a Juris Doctor degree from Yale in 1973, having spent an extra year there in order to be with Clinton."
Finally, Barack Obama "transferred to Columbia University in New York City, where he majored in political science with a specialization in international relations. Obama received his B.A. degree in 1983. He entered Harvard Law School in 1988. In 1990, The New York Times reported his election as the Harvard Law Review's "first black president in its 104-year history". He completed his J.D. degree magna cum laude in 1991."
Ron Paul hasn't dropped out, where did you hear that? Despite the near-total media blackout on Paul since the three days before the Iowa primary, he is still in the race.
McCain hasn't yet clinched the nomination... of course, if he is the nominee, he will lose hard in the general election.
can we photoshop Grant into this picture? I think he was quoted as saying something among the sorts in the van "Nobody ever looks at the good things a person does with their life. But as soon as we make a mistake everyone is incredibly quick to judge us." http://abcnews.go.com/US/story?id=4316184&page=1
Because, if we're talking about historical charicters, I would say they were more like the Anglo-Saxton Vikings. Who liked to go to war and destroy every village they came aross. Kinda like the fraternity boys destroyed their hotel rooms, eh?
Is this another one of these sites that start with a main subject and then people proceed to hijack the thread into useless babble? If so, Im in. Never drive with Fuson unless you want to increase your odds of death.