Gas Efficient Driving

By Lynn Truong on 26 December 2006 (Updated 20 May 2008) 24 comments
Photo: iStockphoto

Your gas mileage depends more on the way you drive than on what car you are driving (of course, smaller is still better). Do you ever wonder why you don’t seem to get the gas mileage that is advertised as the EPA rating for your car? Those tests are conducted under ideal conditions (weather, traffic, car condition) driven by an ideal driver. Most of us don’t realize how much our driving habits affect our mileage, and what little effort it takes to improve it significantly. I can get 47 MPG on my 2001 Honda Civic (EPA’s fuel economy rating for it is 32 MPG for combined city and highway). That’s higher than what most people can get out of a hybrid Toyota Prius. So here are some tips to get better gas mileage – saving you money and helping our environment at the same time.

The car manual is your friend. Everything you need to know about maintaining your car is in your manual. Follow the recommended maintenance schedule. You don’t need an oil change every three to five thousand miles as recommended by Jiffy Lube. But you do need to make sure your engine is healthy, the air filter gets replaced regularly, and your tires are inflated to proper levels. All this information is listed in your car manual. Don’t let the mechanic sell you services you don’t need. But make sure you are doing what needs to be done to keep your car in tip top shape.

Pump up your tires. Fueleconomy.gov states that keeping tires inflated to the recommended pressure can improve fuel economy by up to 5%.

No need for speed. Speeding, cutting in and out of lanes, tailgating, and other smartass maneuvers save you very little time and end up costing you at the gas station. Driving at an even speed is much more efficient than always accelerating and stopping. Don’t smash your gas pedal when you start moving and if you see a red light up ahead, just take your foot off the gas and coast until you need to brake. Chances are it’ll turn green before you even get there. By anticipating stops and accelerating moderately, Edmunds.com found that you can get up to 37% in gas savings. This also saves you from having to replace your brake pads too often. By far, this has increased my mileage the most. I've explained more why speed has such an impact in How to save $0.54 per gallon on gas.

The speed limit is for your gas mileage’s good. Going above 60mph significantly decreases your fuel efficiency. According to fueleconomy.gov, each 5mph you drive over 60mph reduces your fuel economy by 10%.

The windows vs. air conditioning debate. It’s been hotly debated as to whether it’s more fuel efficient to have your windows down or the air conditioning on. The answer is both. At low speeds, having the windows down is a better option. But as the speed increases, having the windows down creates higher air resistance, which decreases fuel economy. According to brainfoodpodcast.com (episode 2), the exact speed where the windows down option crosses over to be less efficient than having the air conditioner on is 50mph.

Stop idling. You use up gas when your car is on idle. This doesn’t mean turning off your car in the middle of the road when you’re in traffic or at a red light, but keep in mind it’s better to turn off your car and restart than to leave it on idle. Also, many short trips taken from a cold start can use twice as much fuel as one multipurpose trip covering the same distance when the engine is warmed up and efficient. You would save on mileage too by not having to cover the same area twice if you plan your errands ahead of time.

The weight in your rear. If you’re carrying excess pounds in your trunk (no pun intended), get rid of it. Weight contributes to your gas mileage too, you know.

Driving efficienctly so you can save money at the gas station is great incentive to be more mindful when you drive. But more importantly it's a very easy and cheap way to contribute to saving our environment. Not to mention it'll make the roads a little safer and a happier place to be.

4
Average: 4 (1 vote)
Your rating: None
ShareThis

comments

24 discussions

Add New Comment

CAPTCHA
This test helps prevent automated spam submissions.
Will Chen's picture

"Going above 60mph significantly decreases your fuel efficiency."

 Thank goodness it is impossible to go above 15 mph on the 405!

Andrea Karim's picture

I always thought that the whole "don't go above 60mph" rule was bollocks, seeing as how you take longer to get places the slower you go, so wouldn't you be spending the same amount of fuel anyway?

Turns out that the gas efficiency curve isn't linear, and I ended up discovering just HOW unlinear it is when I drove over the mountain pass at 30 miles and hour the other day during a snow storm. The whole 150 mile trip usually takes half a tank of gas - this time, it only took a quarter. Insane!

Guest's picture

One picture worth a 1000 words:

Just click

http://www.extra-mpg.com

Guest's picture

One picture worth a 1000 words:

Just click

http://www.extra-mpg.com

Guest's picture
Guest

I was able to average 47.5 MPG out of a 2003 ford focus on about a 300 mile trip driving slow & coasting where I could. Car has a 5 speed

Guest's picture
Jeremy

Has anyone seen a graph of MPH vs. fuel efficiency?

Guest's picture

One picture worth a 1000 words:

Just click

http://www.extra-mpg.com

Guest's picture
Dale Kaup

You don’t need an oil change every three to five thousand miles as recommended by Jiffy Lube.

 

I disagree: The increased lubricity you get from changing your oil will make up for the environmental impact of using more motor oil AND will pay for the oil change. At 20 mpg you'll burn $300 of gas in 2000 miles so it doesn't take much to negate the cost of the oil. Remember the oil isn't discharged into the air as carbon dioxide unless it's burned in which case it's displacing other fossil fuels.

 

If you see a red light up ahead, just take your foot off the gas and coast until you need to brake.

 

I disagree: By braking early you will reduce your speed earlier thus increasing your minimum speed which is really the only relevant factor. So brake early so you can maintain a higher minimum speed and still get to the light as it gets green.

 

Personally I think vehicles over a certain weight should have a lower speed limit especially since they use more fuel and are carrying more kinetic energy at equal speeds to lighter vehicles. Alternately do something to encourage more diesels. Or tax gas to maintain a price at 3.25 or 3.50. If we had had a $1.00 gas tax when it was otherwise 75 cents to 2 dollars we never would have had this shortage driven $3 gas we have now.

 

Dale

Guest's picture
Alyson

Ever. I think it's rated 24 for city and 30 for highway and I usually do about 31 to 33 (mostly city, I drive my husband to the train and then home again, to the store, etc), so it's totally possible to beat the EPA estimates. It's a manual transmission and I do get the most out of hills and stops, it's in neutral a lot (approaching a red light, either the clutch goes in and I coast or I shift to neutral and coast - same with big hills, gears just slow you down on the hills. ) There are places that I can go for miles, literally, in neutral and at the speed of traffic. But, I think my real secret is that I'm a super mellow driver. I play the no braking, no shifting game (ie keeping my speed as constant as possible so I don't have to do either) and coasting when possible. If I'm approaching a stop sign, I take my foot off of the accelerator instead of speeding up until I'm on top of it and then slamming on the brakes. I use hills to slow me down (going up not down) and get pissed off at people who constantly break on hills - it's a hill, take your foot off of the gas. Occasionally people get royally pissed off at me and blow on by (and I really don't drive like a grandma, I"m just not in an all fired hurry) and then I end up behind them at the next light. Good thing they were in such a hurry to get absolutely nowhere.

I think a lot of people don't get good gas mileage because they're brake happy. How many people have you ever seen constantly tapping their brakes in front of you on the highway?? Bonus if they're going uphill. And, two footed drivers whose brake lights are on while they're obviously accelerating? Another bonus of a stick is that you can't drive with one foot on the gas and the other on the break, although I wouldn't ever do that anyway.

Another bonus is that my brakes (at 4 years old, bought it late in '03 and about 40k miles) are maybe 30% worn away, which means they should last until 120k at this rate and the clutch is fine.

Guest's picture
Guest

"Good thing they were in such a hurry to get absolutely nowhere"
Those are the folks I roll up beside and congratulate on getting to the red light a LOT sooner than I did!

Guest's picture
J

This would never work in San Antonio. Drivers have ME-FIRST SYNDROME. They will always do the opposite of what the author mentions in "No need for speed" paragraph. Driving over 80 mph is commonplace in addition to aggressive manuevering. Also, rapid acceleration and braking between red lights is the norm.

Guest's picture
Mommacyr

Thanks for posting. I appreciate your input.

Guest's picture
Shane

I totally agree with you Andrea. I wasn't convinced until I calculated my potential savings at http://www.mpgforspeed.com/ and then I was sold! My tanks go a lot further now!

Guest's picture

I don't how I feel about the speed and MPG thing. If it's really so bad to go over 60 MPH then why are there speed limits in my area that are as high as 70 MPH? Wouldn't the government be interested in conserving the amount of fuel we use and the amount of CO2 that we put out as a result?

Guest's picture
Rob

I have been hyper-driving a bit and gotten 39 mpg out of my 30 mpg Ford Ranger. Part of my technique is to put it in neutral and turn off the engine when I can. I don't need a lecture on safety but I wondered if anyone had a line on the cost of restarting the engine using the starter and the dynamics of just letting out the clutch to restart.

Guest's picture
Rob B

I would just use the clutch to restart whenever possible. That way you are not over-using the starter and constantly turning the ignition key.

If one were to know how, I can see wiring up a switch that will stop the engine, and then wiring in a button that will enable you to use the starter without turning the key. It would make stopping and re-starting the engine much quicker, safer, and easier.

Guest's picture

The biggest consideration on cutting back on transportation costs is to determine whether you can get rid of your car entirely. For most, this would be too large an inconvenience to make a reality; however, what's more realistic is downgrading from multiple vehicles.

If you are one of the tens of millions of American families (or individuals) with more than one car, consider selling one. Whether or not you drive them, cars cost money.

The total cost of vehicle ownership is higher than most think. Besides pumping fuel for every inch of distance you drive, cars require continuous insurance payments and maintenence. Most importantly, cars come with a high opportunity cost on their value.

For instance, if your car is worth $10,000 and you have that much in 16% APR credit card debt, the cost of driving must include the interest payments you could otherwise erase. In this case, it amounts to roughly 1.32% per month, or $131. That's pure interest expense, for which you derive no worldly benefit!

Adding insurance, gas, amortized maintenance costs, and opportunity cost of capital, the monthly cost of driving can easily reach $500 per vehicle. Selling a car could easily mean the difference between being under the water on your bills or financially solvent.

Guest's picture
Guest

This site can help you save gas! Check it out!
www.savinggas4you.com

Guest's picture
Guest

I get 27 on the highway w/ my voyager that's rated at 18 combined. I think its a gas when, on a long trip, the same people pass me several times. I guess they must have stopped to fill up again and I just drove on by! It's also less stress to be the one cussed at rather than the one cussing. Go ahead and cuss me I CAN'T HEAR YOU

Guest's picture
Dale Kaup

Averaging MPG is a farce. Two vehicles one getting 12MPG and one getting 500MPG may average 256 MPG but consume more gas than one getting 16 MPG and one getting 50 MPG that together "average" 33 MPG.

It's a feel good farce. All efficiency improvements should go in the 12-18 MPG cars not the 50-500 MPG cars but for too long the low MPG vehicles have been the golden goose for the industry... No longer thank GOD.

Guest's picture
mcshaun

When you use overdrive gearing, your cars engine speed goes down. This saves gasoline and reduces engine wear.

Guest's picture
dalekaup

We've all heard the calls lately for improved CAFE standards and it sounds good. We'd all like to be able to reduce our personal cost for driving as well as reduce our nation's and our planet's dependency on petroleum. The problem is the proposed CAFE standards (along with E85 capable vehicles) are a feel good measure that actually gives vehicle manufacturers license to produce more, not less, large gas guzzling vehicles.

Lets do the math. Take 2 cars that each are relatively safe and get 30 mpg each such as the Chevy Impala. The pair of them driving 1000 miles would consume 1000/30 x 2 gallons of gas or 66 gallons of gas. Now lets take a pair of vehicles that together average 30 mpg. I'll use a hypothetical 12 mpg vehicle (think Hummer) to average 30 mpg we'll pair it with a 48 mpg Honda Civic (48 +12 = 60 / 2 = 30). Over the course of 1000 miles the Hummer will consume just over 83 gallons of gas. So there's no need to even calculate the Civic's mileage. Even if it ran on sunshine nothing it could do could offset the Hummer's terrible mileage. By itself it consumed more than a pair of Impala's so the idea that somehow we can offset to achieve a goal of reducing gas consumption doesn't even come close to passing the "back of napkin" test.

Another real problem with CAFE standards is that in order to get these offsets car manufacturers need to get us to buy ultra efficient cars. This is how we got the Geo Metro a few years back. So instead of having vehicles of similar sizes on the road we have lots of cars at the extremes. This leads to a partially correct view that small cars are dangerous. They don't have to be, but when built with ultra high MPG as the main goal, they are too small to stand up to a high speed collision with a large or medium size vehicle. This perception of small cars as dangerous leads more people to buy large vehicles "to be safe". This increases the danger to those occupants of the smallest cars and increases the danger to the occupants of the large SUV who otherwise might be in something more sensible such as an Impala. The Impala is safer than the Hummer because it doesn't roll over as easily AND people in Impalas are more likely to wear their safety belts.

CAFE standards that allow averaging simple MPG numbers rather than averaging gallons of gas consumed lead to unintended consequences that we can't live with.

Guest's picture

To optimize the mileage of your vehicle, keep your tires in good condition. Making sure that tires are efficient will save you gas (and money) because it will ensure that your machine does not consume excessive power when overcoming the consequent resistance created when your wheels start rolling during motion. In addition, if you want to replace your wheels, make sure that you consider both aesthetics and fuel efficiency. You vehicle was designed to work at its best with certain wheel specifications. Hence, get advice from experts regarding the best size and type of wheels for your car. In general, less strain on the gas engine allows your car to consume less fuel.