The Comprehensive Guide to Saving Money on Gas

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Introduction: The Comprehensive Guide to Saving Money on Gas

Tired of paying out the nose for gasoline? We all are, and while most of us can't give up our cars entirely, and there are things we can do to ease the pain.

The popular option to consider is getting new transportation entirely. Both diesel cars and hybrids can get over 50 miles per gallon, which can add up to major money savings. I wouldn't recommend buying them unless you are already planning on buying a replacement automobile, as the cost will take a while to be offset by gas savings. Likewise, purchasing a motor scooter for short trips can save a lot of money if you make enough use of them. These scooters can get over 100 miles to the gallon, and are a blast to drive, so crunch some numbers using this calculator this calculator

The best options of course are to make better use of public transportation, walking and biking, but for many of us, these options don't fit well into our lives. With this in mind, I've assembled a list of tips and tricks will help keep as much green in your wallet as possible while still staying mobile.

If you like this article, please check out my website at http://www.rickywillems.com

Step 1: Steps 1 & 2 - Easing Up on the Gas


There have been a lot of articles online about how to cut down on your gas consumption, but
hopefully this should have some new tricks, and a good list of old ones.

There are two genera of ways you can stretch the mileage of your vehicle. You can modify your car, or you can modify your driving habits. Obviously, modifying your driving habits requires less time, work and no money on your part, so I suggest you start there.

Smart Driving Habits

1: Slowdown Leadfoot!

This is the most off quoted of ways to save gas, but it deserves to be, as it's epically important. On highways, cars have a sweet spot for gas mileage. It's usually somewhere between 55 and 70. Experiment a little and see where yours is. If you don't know, and you have a newer car, 65 is a safe bet.

The common statistic is that every 5mph past 65 you go, you lose 3mpg.
https://www.instructables.com/files/deriv/FAY/910H/FKD1HMY6/FAY910HFKD1HMY6.MEDIUM.jpg

2: Accelerate Smart

Accelerating faster than you need to really kills gas mileage. You've got a speed limit anyway, so why race to get to that limit as fast as possible? Overall, it's how close (or how far above) that speed limit that's really going to make a difference in how fast you get somewhere, so speeding up faster makes a minimal difference anyway.

My trick for accelerating in a smart manner is as follows:
(I don't think you'll find this method anywhere else, so listen up)

- Get out on the highway, and once you're up to your cruising speed (60mph or so) look at your tachometer (that's your RPM gauge, as pictured. You may not have one, and investing 20 bucks or so in one might not be a bad idea). Look at your engines speed. This is all the power your engine needs to run at full speed, it's where your engine gets its best gas mileage, so you shouldn't need to rev you engine any higher than this in day to day traffic.

For one of the vehicles I drive, this RPM is 2100. I do my best to keep RPMs under this level. I
do this by not pushing as hard on the gas pedal, but also by momentarily letting up on the pedal as it approaches that speed. That lets the automatic transmission shift into a higher gear. If you have a manual car, simply shift when you get to this engine speed. For me, 50% throttle at 1200 rpm's uses less gas than 10% throttle at 2500 rpm's, experiment with yours.

Based on fuel maps from several common cars, this seems to often be the case. Also, short shifting is a way of limiting yourself from accelerating aggressively. If you keep yourself in a low gear until you need extra power, you will be more mindful of the extra fuel you're using to accelerate. Likewise, being in a higher gear reduces the "step on the gas and take off" result in pushing the gas, which tempts many a driver. Overall. it keeps you out of higher RPMs, which tend to use more gas compared to lower rpms, regardless of your throttle position.

Short shifting (shifting earlier than you otherwise would) is often helpful. If an engine is turning twice as fast, its pumping more or less twice as much air. In turn, your engine will be injecting more or less twice as much gas. Higher rpms are there to provide you with more power, if you need it. If you dont need the extra power, keep them as low as you can. (this is not applied in cases of downshifting manual engines, in which case fuel is often shut off entirely). Mind you, do not short shift to the point that your car feels bogged down and underpowered, as this is both inefficient and in the long run harmful to your car.

Just making this change to your driving habits can make a huge difference. I was a conservative driver to start with, and this still helped substantially.

Step 2: Steps 3 & 4 - Ease Up on the Brakes

Avoid Braking (but don't kill anybody!)

As you brake, you turn the energy of your moving car into heat. That energy comes from gasoline! If you see a stop ahead, let off the gas immediately. There's no sense using more gas to get closer to a line of waiting cars when you'll just be waiting there anyway.

To go a step farther, break just enough so that you will arrive at a light still moving as it changes. You vehicle uses the most gas to move from 0 mph to 10 mph. Avoiding a complete stop by timing lights correctly will really improve your mileage. Sometimes you can change a lane to avoid stopping, so do that whenever (safely) convenient.

Coast Down Hills and Up To Stop Signs.

To take things a step further, take your vehicle out of gear as you coast to a (almost) stop. This will let your engine drop its speed to idle, using less gas, and it will let you coast farther
without using any extra gas. The same thing goes for hills. Down a large hill, your engine becomes a drag on your vehicle rather than a power source. So shifting into neutral can let you car coast longer and faster than it would be able to when in drive.

(caution here, mis-shifting, shifting too often, or shifting while revving the engine can all cause undo wear and tear automatic transmissions. Use judgment, and make sure you're careful and practiced before you try this on large or busy roads. Also, if your vehicle has a steering column shifter, this can be difficult and you could potentially shift into reverse by mistake, so it is not recommended.)

::EDIT::
Wow Ive got the most feedback on this suggestion. Here is my reply.

Yes. Modern cars with manual transmissions -do- shut off fuel to the engine when costing in gear. This can save gas. You should keep your car in low gear when slowing down, and in high gear when on a steep hill if you would otherwise be using you brakes.

If you are coasting down a small hill though, or want to pick up speed down a hill, take your car out of gear! That gas you might save by keeping your engine in gear is very small compared to the gas you could save by not having to use the accelerator as much.

Looking at the tech-specs for some of my own vehicles, even under a relatively small engine load, I would have to have my engine out of gear for 12 minutes to make up for 1 minute of acceleration. In other words, I'm saving a fair amount of gas if I avoid accelerating by keeping my downhill speed up. Obviously this varies from car to car.

Use your judgment and experiment, but taking your car out of gear at appropriate times really can save you considerable fuel.

Step 3: Steps 5 & 6 - Bad Habbits


Don't Idle
Idling in your car equates to 0mpg in your average. There's an old legend that starting your car takes more gas than leaving it idling. This used to have a grain of salt to it, but in modern fuel injected engines, it's not the case. Even idling for 30 seconds uses far more gas than starting your engine. The only hitch is that repetitively starting your engine adds additional wear and tear, so best bet is to avoid situations where you would need to idle entirely. Other than that, it's a trade off. (for my vehicles, If I'm planning on waiting any more than 2 minutes I turn it off)

Don't Carry Extra Weight!

If you own a van, and you don't normally use the removable rear seats, remove them until you need them. If you have a hundred pounds of stuff you've left in your trunk, clear it out. If you don't know how to or wouldn't want to change a spare tire (which you should know how to do) replace it with a can of "Fix-A-Flat" (a good thing to carry anyway). The rule of thumb is every 100 pounds dropped is another mile per gallon.

Step 4: Steps 7, 8 & 9 - Good Habits

Cut back on the AC
When you're driving around town, (anything less than 50mph) Roll down the windows instead. A/C can drop or mileage by as much as 8%.

Park in the Shade
Gasoline evaporates easily, so having a hot car means your money is floating away! Plus, you'll likely turn on your AC to compensate.

Turn it to Economy Mode
Many cars now have an Economy/Sport/Winter setting switch, or an "Xtra PWR" button somewhere. These can drop you mileage depending on your car and your driving habits. Stay far, far away.

Step 5: Steps 10, 11, & 12 - Gassing Up

Check Gas Prices Online

There are a few great websites that list the cheapest gas prices in your area, so why not use them. You can save 10 or 20 cents on the gallon at gas stations you might not of seen otherwise. Don't however, drive 20 miles out of your way to get the lower priced gas, you'll lose you're benefit. Also, while you're filling up, why not check your air filter and tire pressure?.

"Hmm, Tip 11 was removed, so I need a new tip.."

Get a Gas Card

I personally don't like to use credit cards, but for gas, I can save 5% on each purchase.
Considering I purchase about $8,000 in gas a year, that's about 400 bucks. It also lets me fill up faster and not have to worry about creepy late shift gas attendants (no offense guys)

Step 6: Steps 13 & 14 - Gas to Avoid

Don't use premium gas if you don't need it!

If a car requires premium gas to run, use it. Otherwise, it's a waste of money. Higher grade gas does not perform any better, it's simply made to run in different engines. Buying higher grade gas is not a treat for the car, and it's very costly to do.

Some newer cars, usually performance models, have engines that will adjust themselves to higher grade gasoline. (these will usually say "Use XX Octane Gas for best performance" or the like) They run at an effectively higher compression when using higher grade gas. I do not know first hand, but it seems possible they could run more efficiently using a higher grade gas. Id recommend trying both, and see which option ends up saving you money.

Avoid more than 10% ethanol blend

Or avoid ethanol entirely. Ethanol contains less energy than gasoline, and can lower your mileage, without lowering your price. Experts say that 5% to 10% ethanol can help burn the gasoline more effectively and it makes up for the loss in some cars, but any more than that percentage and you'll drop your mileage as much as 10%.

Step 7: Steps 15 & 16 - the Obvious


Drive Less

Obviously this sounds horrible, but it doesn't always have to be. Plan your errands so they can be done with one trip instead of two or more. This is doubly important because short trips are terrible for both your engine and your gas mileage.

Park in the first spot you find. Driving around looking for a better spot takes more time than
walking does, uses a ton of gas, and we could all use the exercise anyway.

Maintain Your Car

Keeping your tires properly inflated, your oil changed, your transmission serviced, your air
filter clean, fuel injectors cleaned, and other routine maintenance can make a huge difference. Any one of those factors if left out of check can hurt mileage by 10% or more.

Step 8: Modifying Your Car - Steps 17 & 18 - Minor Modifications


Modifying Your Car

Not happy with the results? Need to save even more gas? There are certain modifications, both basic and complex that can increase your mileage substantially.

Low Rolling Resistance Tires.

Many hybrids use these types of tires, and they can increase mileage 15% or more. They are not all weather tires though, so if you get a lot of snow in the winter, these are probably not for you.

Synthetic Motor Oil

Synthetic motor oil can increase gas mileage substantially. I've noted about a 5% increase in gas mileage on vehicles that have switched to synthetic motor oil. Synthetic costs more however, and although it can go longer between changes, it may not make up for the additional cost. (It may, do the math for your particular circumstance, taking into account the money you'll save on gas as well). Personally, I grab it when it's on sale and use it to great success.

Step 9: Steps 19 & 20 - Major Modifications


Cold Air Intake/High Performance Air Filter

A better air filter and intake make it easier for your engine to breath, and can increase you
Mileage another 5% or so. It really depends on the car; some cars have very free flowing intakes, some have an extensive system of baffles and poor air filters. Replacement free flowing air Filters can cost as little as $20 online and are defiantly worth the money for most.

Free Flowing Exhaust

Free flowing exhaust is a change that, while it can increase mileage, is usually more trouble
than it's worth. If your engine is breathing in more easily, you also want it to breathe out more
easily. The trouble is, exhaust systems cost hundreds of dollars plus the installation costs, and unless chosen wisely can hurt mileage as much as they can help.

Decrease Drag

If your car has a roof rack you don't use, or a radio antenna you could do without, or a rear hood ordainment you don't particularly car about, get rid of them. If you want to get a little more serious, you can use foam, Plexiglas, tape or the like to smooth over places on your car that are not aerodynamic. If you own a truck, a truck bed cover or a rear cab can also very much increase your mileage. On some cars (research this first) a rear spoiler can help aerodynamics, though commercially sold spoilers are not designed to do this.

If you really want to go crazy, you can follow this guy's lead, and get 100 miles per gallon.
http://www.autobloggreen.com/2007/12/27/aerocivics-mods-combine-great-aerodynamic-and-a-um-stunning-l/

Step 10: Conclusion


Well guys and girls, that's it. Hopefully these tips can help transform that gas guzzling monster in your drive way to something a little more manageable. When all of these methods are employed, most people can -easily- double their mileage, some can far exceed double.

Best of luck. If you enjoyed the instructable, please check out my website. http://www.rickywillems.com

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    69 Comments

    it took a round trip from Chicago, Illinois to Canton, Ohio to get my wife to believe this one. She drives a Honda Civic Si and it says PREMIUM FUEL ONLY on the door for the gas cap. i told her to fill up with premium for the trip there and then run the tank almost empty while there and then only use regular on the way back. She took my ScanGaugeII and got 31.7 MPG  on the way there and 30.9 MPG on the way back. And for all we know that variation could have been caused by wind. Either way that .8 MPG increase isn't worth the extra 20-25 cents a gallon.

    2 replies

    That's really not a valid check due to altitude changes, wind speeds, ect, different brands/mixes, ect. Chicago is one of the cities that uses its own boutique fuel blend, which your Civic may not have liked.

    A valid check would be a 5 tank average under what is your normal driving conditions. Run 87 for 5 tanks, then run 93 for 5 tanks, and see what the average is. When comparing things like this, keep as much the same as possible.

    Thanks for the live data, I had often wondered about this. Does fuel choice affect warranty on cars specifying premium fuel?

    "50% throttle at 1200 rpm's uses less gas than 10% throttle at 2500 rpm's" Another in an endless line of impossible statistics. Where are the numbers from? They do look impressive and make a person feel good, though. "The engine is more efficient when it does not have to pump air past a closed throttle." An engine does not pump air past a throttle, it sucks air past it. It has no impact on efficiency. Cam profile, injector pulse width, throttle position, and engine RPM dictate efficiency. A Honda Civic I used to own turned 2250 RPMs at 55 to 60 MPH. Honda engineers probably had a reason to have the car in that powerband at highway speeds. I have commented on other Instructables on increased gas mileage, and I will again say please pardon my intolerant tone, but efficiency vs. RPM varies from car to car, and oversimplifying it is misleading. Unsubstantiated statistics and numbers imply that whoever states them knows what they're talking about, further confusing the mileage issue. Lighten the car, easy on the gas pedal.

    5 replies

    Make a database on your PC and implement date, mileage, fuel quantity you read on display and calculated on price end expence , fuel price, air filter and oil changes, tire pressure checkings, whatever you consider important and in a few months you'll see what really happens with your car. I do that since 2005, quite boring but you'll find out many actual facts on this subject.

    I would argue pumping air past a restriction is effectively the same as sucking it through. That being said, after looking into it further, this only makes a difference at near the engines limits, so it probably isn't relevant. Its the same argument as clean vs dirty air filters actually. And, you did actually catch another mistake for me, I meant to make it clear that the 1200 vs 2500 was specificly the results for a vehicle I own. You're absolutely right about honda engineers having a reason the engine maintains that speed, and that every car is different. Thats the whole point of this page of the article. In your case, the "sweet spot" that Im recommending you try to stay around or below would be 2250. What I found is that engineers usually design their cars to be most efficient at highway speeds (no surprise), and that by operating your engine at a similar rpm as you would on the highway, mileage can increase.

    Also, for a little more lovely math.

    Im just pulling off a generic Toyota fuel map. (back calculated volumetric efficiency based on MAP readings, engine load, throttle position, ect)

    VE at 1000rpm, 50% throttle = 71%
    VE at 2500rpm, 10% throttle= 54%

    to find the relative amount of fuel being injected (assuming all other factors equal), simply multiply rpm by VE.

    710 at 1000rpm 50% throttle, 1350 at 2500rpm, 10% throttle.

    710/1350=~53%,

    meaning 1000rpm 50% throttle uses around half as much gas as 2500rpm at 10% throttle.

    This is assuming certain other variables are constant, which is likely not the case, so this figure is an estimated example only.

    Your work to support your claims surprises me. It's no secret that the tone in my citicisms was very dismissive. We now fing that you are not simply shooting from the hip, but instead have made very informed statements about mileage. Good job.

    You were quite right to criticize, I provided none of the reasoning or math for my suggestions in the article, and with the unfounded claims that get thrown around on the internet, I should lend credence to myself and show my work. To an extent, it's still shooting from the hip, I cant say these figures are always true for every car, but they are tips and guidelines, not a scientific paper full of hard-fast rules. My inclination was that the reasoning and math would be beyond the scope of the article, and beyond what most people would care to read, but perhaps the average instructable reader wants a bit more.

    Any car buil in the last 20 years or so has a sealed fuel system, parking in the hot sun or in the shade makes no difference at all since any fuel vapors caused from evaporation are captured inside the sealed system and will return to a liquid state once they cool down. In fact, newer vehicles ("96 and up) generally have a sensor built into them so that if you don't tighten your fuel cap all the way (to capture the vapors), your check engine light comes on. A good idea if you drive an older car I guess, but useless for anything "recent".

    2 replies

    That's true, there are two pipes from the fuel tank, one comes from the fuel pump inside the tank, the other takes fuel back from engine to the fuel tank. Consider that the fuel pump cools and so endures more it's working life if submerged by fuel. That means more or less something like two gallons fuel in your tankat least. Remember it does exist a fuel filter too between the fuel pump end the engine, better to clean , possible in some diesel engine, or change. It surely helps pump life too and I can tell gas pump failure is a real bad nightmare, I changhed mine in a parking lot, a most difficult task I ever tried . Gas filter in my car was almost filled of an unclassified black dirt after 50.000 miles when I changed it .
    Clean new engine air filter and a well checked tire pressure are mandatory as it results in my personal mileage, fuel, oil and filter changes database. Keep a hand or pedal air pump in your trunk it may help or even save a lot.

    so why do new cars have a fresh air tube on them?? If the system is sealed and you pump all the gas out of the tank you'll have a vacuum in the tank and won't be able to get the cap off to refill it.

    im having a hard time figuring out where you are getting your data from

    2 replies

    Depends on which data you mean. A lot of it is personal data collection using the vehicles I have access to and an OBDII laptop connection and log tool. Other parts are government sources, as well as other sources.

    i guess it would be the one on your speed reflecting fuel mileage, i know you lose fuel economy the faster you go but 3 mpg per 5 mph? that seems a little drastic to me. i drive a 2005 f150 with a 5.4l, at 110 kmph (i live in the great white north) i pull 21 mpg over a distance of 450 kilometers and use roughly half a tank, now at 145 kmph i get slightly less then that, i think the last i checked it was roughly 19 mpg. sorry i have no idea where i was going with this, i sorta lost my train of thought half way through.

    Good hints!. Still, a very important one has been missed (i guess): get a low mpg car. Imported Europeans are the best/more common on fuel saving.

    For instance, I have a little Citroen (diesel, 5 seats, 1992) in which I ride every day to university. Most is country roads, but include some city traffic and a few pedal-to-the-metal moments. I never went below 52 mpg (us gallons). Back in the 90s, an advertised announced a best of 64 mpg for this car. It held a record for economy until 2008, lost for a Peugeot HDI)

    Cars that go below 25mpg are quite rare in Europe. They're either big luxury cars, US cars, or pre80's. Maybe because we rely on small blocks, I don't know....

    if your going down a hill, throwing your car into neutral is actually detrimental to you fuel economy. Most new cars (2001 and up) are fuel injected, and when coasting down a hill in neutral, your car uses x- amount of gas to keep the engine idling. If your car is in gear going down a hill, the injectors will supply the engine with less amount of fuel than it would while idling. think of it this way...if your coasting down a hill under no acceleration from fuel, then the tires are spinning the engine, so why should the gas have to?

    2 replies

    I also meant to add, keeping your car in gear also slows your car down depending on your speed, gearing, incline, ect. This might be fine, but it might also be a waste of potential energy you could be using to speed your car up. Cruising a little faster down hill means having a little more momentum to go up the next. (staying within safe speed limits of course)

    This is true on some fuel injected cars, but not others. For example, I tested this in a 2009 Mini-Cooper about a week ago. According to it's ECU hooked to my ODBII reader, it used several times as much gas when decelerating in-gear than it did when out of gear, depending on the engine RPM. I've tried it on other cars as well, with abut 50/50 results.

    user

    That was an ok way to save on gass but we need more modifcasons than driveing habits.