Eco-Driving for Increased Fuel Efficiency
by Motte Brown on 05/15/2008 at 12:41 PM
While commuting to work this morning, I put my car in neutral and coasted whenever I approached a downhill. It's a fuel efficiency technique called the Pulse and Glide. And it's part of my daily battle to see if I can get more than my current 22 miles per gallon average for city driving.
Other things I'm trying include:
- Driving slower
- Coasting to stoplights, stop signs and parking spots
- Accelerating slowly from stops
- Keeping windows and sunroof closed
- Parking in pull-through spots
- Clearing out my trunk
I found these tips on Ecomodder.com. They have tons more for all you polar bear savers out there (and I say that with great affection). My goal is simply to improve my gas mileage from 22 to 30+ miles per gallon. I estimate it'll save me about $25 a month.
Oh, and I'm also taking advantage of a local grocery store's promotion that saves me 20 cents a gallon for every food purchase over $50.
So what are you doing to cut down of fuel costs?
1. Dan Gill said the following at 12:57 PM on May 15:
To cut down on fuel costs (not of), I ride my motorcycle to work (44 mpg) vs. driving my truck (13 mpg) when the weather isn't just absolutely deadly for the motorcycle. When in the truck, I try (try, mind you) not to accelerate as quickly as I really want to.
Pulse and glide is a horrible thing to do to other drivers. Imagine following someone who drives like that. I hope you aren't caught up in someone's road rage.
Pulse and glide is also dangerous. One danger is the unpredictability of your driving. The other danger is shutting off your engine. I hope you aren't doing that. Frankly, I hope you give the whole thing up. It's selfish and inconsiderate.
2. Motte said the following at 1:04 PM on May 15:
Dan:
Be assured, nobody is waiting on me and I keep my speed consistent. Part of the technique involves keeping your momentum.
And no, I don't turn off my engine.
3. Tom Neven said the following at 1:07 PM on May 15:
Putting your car in neutral and coasting downhill is probably a false savings; you're putting extra wear on your brake pads since you don't have the drag of the engine to help slow you down when you finally do need to brake. (And oh for the days when automatic transmissions used torque converters instead of electronic sensors, which provided further aid to your poor brakes.)
And if you drive a manual stick shift, beware of coasting with the clutch depressed; you'll destroy the clutch's throw-out bearing in no time.
4. obewan said the following at 1:10 PM on May 15:
Pulse & glide might work well in hilly terrain. My brother in law used to do it all the time. There was a huge hill about 1-1/2 miles long, and he would shut off the engine and coast all the way down the hill, through 2 right hand turns, and then into his apartment parking slot. He is a real pinchpenny.
Me? I just bought a new Honda Civic. My old Neon only used to get 22 mpg city in spite of being a small 4 cyl. The Honda gets 28city and 34 hwy. I think having a manual transmission is a big help.
GM has a half a dozen or so cars now that get over 30 mpg, so things are finally moving in the right direction.
5. DannieA said the following at 1:13 PM on May 15:
elements of life include going to work and back home.
Elements of savings can come in this manner:
1. Weekends with friends...meet and carpool each taking turns...and others leaving $5 to help with gas. win-win
2. plan your grocery shopping coming from work...it's better to be efficient instead of always going back home....and then going out again.
3. keep overall maintenance of car...clearing up trunk included...air in tires....check-ups.
6. Tom Neven said the following at 1:16 PM on May 15:
And the more I read about "pulse and glide," the more I realize it's insanity -- and dangerous.
Never ever turn off your engine until you're ready to leave the vehicle. Doing so shuts down your power steering and power brakes, and in an emergency you're left with no way to react, whether that means a quick swerve, a quick brake, or accelerating out of the way.
Sorry to contradict you, Motte, but pulse and glide is dangerous.
7. mindlab said the following at 1:21 PM on May 15:
I've never heard of 'pulse and glide' but I've been doing it for years; besides being more fuel efficient, it's also easier on the equipment, more polite than jack rabbits and toe stands, and safer. The only problem is the cost of the additional shifting wear if you drive a auto-trans.
One note: The energy you are saving by closing the windows at low speeds (<50 mph) is almost immeasurably small; don't bother. At high speeds, dynamic losses become significant quickly (since dynamic energy losses in fluid are approximately a square function of velocity), but you never achieve such 'high' speeds in your car.
8. Christina (in green) said the following at 1:30 PM on May 15:
I'm gonna buy a manual to replace my automatic. I still need to look into vehicles with better mileage. I was also considering looking into bus routes close by travel.
AND, buy a bike to ride to work.
Currently, I live really close to work - one tank of gas (17 gallons) lasts me 2+ weeks.
With a bike, i could do most of my daily travel minus grocery shopping without getting into my car.
9. Motte said the following at 1:32 PM on May 15:
Not at all Tom. I appreciate the qualification you're giving my post.
I agree, turning off your engine is dangerous. I just gear it to neutral ... which may have its own dangers.
10. Nick said the following at 1:43 PM on May 15:
I started practicing some hyper-miling techniques a few weeks ago, and recently increased my mileage from 38 to 43. I drive a new civic (manual). I think the greatest savings come from not starting quickly, not feeling the need to be right on the tail of the guy in front of you, and looking far enough ahead in traffic to anticipate stop lights. If you know you are going to stop, what is the point of continued acceleration (assuming you aren't adding delay to the people behind you).
Oh, and how about this one: keeping a reasonable speed on the highway. Going 60mph instead of 70 probably saves me 3-4 mpg.
Oh, and as far as hills go, if I don't have to stop at the bottom, I just put it in neutral and let gravity instead of gas maintain my speed.
11. nikki said the following at 1:55 PM on May 15:
Yes there are things to do that save fuel, but to simply save that much MONEY there are much easier, and saner, and safer, methods. Eat cheaper, don't go to movies, only rent library books, cancel the 5,000 channel cable, etc. That $25 per month will be taken care of in no time and you won't have to stress out about driving sensitively (if you still want to that's fine, you can save $50 a month). I don't get how this is such a big problem, when there are SO many other far more effective ways we can save money.
12. Rebekah said the following at 2:30 PM on May 15:
BICYCLING.
I bike commute whenever possible on weekends and occasionally on the way to work. This decreases my gas usage by no less than %30.
When I do drive, I do all of my errands on the way to and from work.
I agree with Nikki---it's easier to save money. If you have cable, internet and a cell phone you will spend (according to my uncle who did the math) $17K over the next 10 years. Wow.
13. Rebekah said the following at 2:35 PM on May 15:
BICYCLING!
On weekends, I bike commute 2-3 times per weekend. This decreases my gas usage by at least %30.
During the week I do all my errands on my way to work or home.
14. BDB said the following at 2:40 PM on May 15:
Tom (#3) wrote:
>>And if you drive a manual stick shift, beware of coasting with the clutch depressed; you'll destroy the clutch's throw-out bearing in no time.<<
FWIW, when I drove a stick, I often didn't need to downshift to "coast" to a stoplight. Never needed to replace a clutch in 250,000 miles. That was on a Saturn, though. A couple of them...
Motte - you can always go from 22 to 30 MPG by putting your famiy into one of those little unsafe cars...or by getting a longer commute where you drive 55 for a lot of miles. Either way will work.
15. Mike Theemling said the following at 2:58 PM on May 15:
The most effective thing that people can do to save gas/money: Drive slower
However, with 75+ MPH speed limits the norm (with many going much higher) it's not likely to be a widespread practice anytime soon.
16. Mike Theemling said the following at 3:24 PM on May 15:
There is one tip not mentioned which is also a huge culprit for poor gas milage: Having underinflated tires.
Be sure to have your tires inflated to the correct pressure.
17. BDB said the following at 3:34 PM on May 15:
Rebekah reminds me that I did, in fact, buy a mountain bike with a lot of gears. I quickly realized that I lived on a hill. And it seems weird to bike around carrying a garage-door opener.
On the other hand, I also discovered that there are so many Starbucks around here that it's a nice walk.
If I could just figure out what the high-school girls are yelling when they drive by...that's unsettling...
18. DannieA said the following at 4:26 PM on May 15:
Mike (#16) I was going to take offense that you said no one had mentioned anything about air in their tires when I realized that my comment may not have been approved yet.
For people that can't bike to work either because of professional dress (heels on a bike may look silly) or because their job is about 30 min. away...I think look for ways to save money so then you don't have to be so uptight about gas money.
19. ptschett said the following at 5:31 PM on May 15:
I've noticed that I am taking it easier driving. Somehow I got 58 mpg out of my motorcycle (Kawasaki KLR650) on a leisurely trip a few weekends ago.
Also I've been trying to drive my 25-mpg car ('96 Ford T-bird) more than my 17-mpg pickup ('05 Dodge Dakota), and I've been addressing the car's minor emissions sensor problems.
Part of me wants to replace the old car with something newer and smaller, but my math right now says I'm better off waiting until these vehicles' useful lives end, or until they stop meeting my needs.
20. Alyene said the following at 5:37 PM on May 15:
Yay! I'm glad others are biking to work! In fact, this week happens to be "Bike to Work Week" and there's still one day of this week left to get started on that... http://www.bikeleague.org/programs/bikemonth/
DannieA, when I plan to wear heels, I usually just carry them with me in my basket and change once I get to work.
I just started biking to work this year... It's been good for me, the earth, and my wallet :-)
21. Rachael said the following at 6:03 PM on May 15:
Wow, I didn't know about the 'go downhill' in neutral trick. Scary. Maybe I can try that some day if there are no cars in sight...just in case...except that there are usually cars in sight when I drive down hills...
Well I usually bus it to work. Perhaps I'm saving the environment by default. In fact, as of yesterday my car became a "pleasure use" car for my insurance! Woo-hoo! (I should've changed it over in January, though...)
I do drive a lot to various activities and random stuff, though, so, I do drive a lot.
Anyway, back to the hill tip. Are there any tips to saving on gas when driving up hills?
Oh, I guess one gas-saving tip I've done is use my Safeway club card. But I don't always get gas there and am not sure if the gas there is cheaper than the generally cheapest one.
Gas is so crazy expensive nowadays. Back in the day it used to be around $1, early $1s, and maybe even late .80s/.90s...back in the day.
22. Rebekah said the following at 7:07 PM on May 15:
When I bike to work, I pack clothes in a backpack OR on Monday I'll bring clothes and food for several days then I would just ride in for the next few days.
It ends up being about organization.
An added bonus is that I get about 30 minutes to get my thoughts organized on the way to work.
23. Kellie said the following at 7:53 PM on May 15:
I drive as part of my work (which thankfully includes as much fuel reimbursement as the IRS alllows) so I try not to look too closely at the gas pump when I fill up 2-3 times a week. Not to mention I have a trunk full of equipment. On the plus side, my car easily gets 30 miles a gallon and I help people in need. So, it's worth it.
24. DannieA said the following at 12:23 AM on May 16:
Rebekah...but then don't you have to change when you get to work and then change back before coming back from work?
You can get your head together in the car too (I usually have my radio off or pop in a cd with short devotional readings...I do it in the car on the weekdays and on the road running 12 miles on the weekend :)
25. Leah said the following at 2:03 AM on May 16:
Putting your car in neutral and letting it coast will make you fail your driver's licence test in Queensland, Australia.
Tom Neven- a handbrake will work with the engine off, no?
26. Dan Gill said the following at 7:12 AM on May 16:
Motte, if you are doing pulse and glide like the link you posted says, you cannot possibly be keeping a steady speed. Accelerating to 70, then dropping down to 50, then accelerating back to 70, etc. cannot by any stretch of the imagination be considered steady.
If you are keeping a steady speed, you might as well just use your cruise control.
27. Chris said the following at 9:58 AM on May 16:
For those considering switching to a manual transmission, be careful. Some automatics now actually get better mileage (though not much) than manuals due to better shifting than what a human can do.
On older models, however, you can probably get some small mileage benefit. Personally, I like saving the wear on my brakes by downshifting......
28. kaj said the following at 11:34 AM on May 16:
I drive a "manual" and my town is silly with hills. I like to shift to neutral and coast (engine still running, never turned off) in residential areas and side streets. Usually the next uphill incline keeps me from going too fast, if not a stop sign or a red light.
The one time I might turn my engine off is if I'm stopped at a railroad track while the train goes by. This is rare, but there's no point in keeping the engine on for 5-10 minutes if I'm going nowhere
I have a question for the resident engineers of Boundless-Land: Except on two stretches of interstate in my region (very steep inclines in the natural terrain), I find it practically impossible to coast downhill on the interstates. My hypothesis is that the people who engineered these roads did so on purpose, to keep the ability to coast to a minimum, for safety reasons. What can you tell me about highway engineering here?
29. lexee said the following at 12:03 PM on May 16:
i live 20 miles from my university, and almost everything else in my town. recently, i have been driving around 55 mph on the highway, given that i am not slowing up trafic for other cars behind me.
i use cruise control CONSTANTLY. even for shorter stretches of road. this helps extremely.
also, i received an e-mail that says filling up in the mornings, as opposed to midday or even evenings, can help you get a little more gas in your tank. this is because when the temperature rises, gas expands. so buying in the morning allows you to get a little bigger bang for your buck. i did this recently, and noticed that i was able to go several more miles on my tank before filling up again.
30. P&P said the following at 12:31 PM on May 16:
The best thing you can do is not drive at all. I truly envy those who can bike to work.
As it is, I drive to a commuter rail stop and take the train into the city. My company offers free parking, which I do use on weekends when I'm out and about, but I do my best to drive in during the week. It saves gas, wear and tear on the car and also gives me time to read or catch up on my knitting.
I've also noticed that when I take the train I'm calmer as well. I guess being stuck in traffic does not do well for my blood pressure.
31. hxcjf said the following at 7:55 PM on May 16:
sheesh, if you're that worried about it, buy heating oil futures...they're highly co-related to gas prices.
32. ptschett said the following at 7:22 AM on May 17:
kaj: the interstate highway system is intentionally designed to have grades no more than 6% (i.e. 6 feet of rise/fall in 100 feet of travel.) It is for safety reasons, it helps truckers control their downhill speed and maintain their uphill speed.
33. jcs said the following at 9:32 AM on May 20:
Leah: The handbrake will work with the engine off, but it's not nearly powerful enough to stop a speeding car. The handbrake was designed to keep a stationary car from rolling away, not to stop the car.
PLEASE don't turn your engine off while driving...when you shut off your engine, your power brake booster will remain pressurized for a short time, which will keep your brakes working for a few seconds and give you a false sense of security. When your brakes suddenly depressurize and fail, what will you do?
Also, why would you shift your car into neutral when going down a hill? Just let go of the gas pedal -- this will close the throttle and you'll use the same amount of gas, but your brakes will last much longer.
34. ptschett said the following at 6:29 AM on May 22:
I thought of another reason to not coast down hill with the clutch pedal pushed in or in neutral: in many places, it's illegal. (Not like the police have much chance of knowing you were doing it, but we're all trying to be law-abiding citizens, right?)
35. da kid in skl said the following at 7:37 AM on May 22:
i drift proper in mi car forget u geeks
36. gershon said the following at 1:49 PM on May 28:
I drive a car with manual transmission, manual steering and no power brakes. So if I'm not in traffic, what's the harm in turning off my engine and turning it back to on and coasting with the clutch on? It's surprising how slight a hill is needed to maintain speed. A car behind me wouldn't even notice I did it. Let the clutch out and the engine is going again.
It's an amazing fact that half of every round trip is downhill. (Unless it's absolutely flat.) On most of these downhills it's possible to turn off the engine and use zero fuel.
In normal city traffic, cars bunch up at lights and form packs. In order to hypermile, it's best to stay in that nice safe clear space between the packs where nobody is behind me when I slow down a bit while coasting. And I avoid the need to slow and accelerate.
Is coasting dangerous. In order to do it successfully, one needs to intensely pay attention to traffic and road conditions. When I ride my motorcycle, I'll take that anyday to to the people who pass me while texting on their cell phone.