Increase Miles Per Gallon Instantly




Many people drive and unless you are one of the "lucky" few who uses coal to heat up the boiler on your 1923 Stanley Steam car than you probably use petroleum distillate, better known as gasoline or diesel.
Unfortunately burning these fossil fuels produces carbon dioxide, a greenhouse gas, around 6 pounds of it per gallon of fuel. Try to stay with me as I go through the math, 25G fuel tank * 6lbs per gallon= Erratic weather patterns and an unhappy enviroment (and 150lbs of CO2)

We can help the Earth out if use this fuel efficiently. There is a way to drive to increase your MPGs drastically. How drastically? I have personally gotten a Ford Excursion to go from 8-9 MPG City to 19-23 MPG City. That's almost a 300% improvement! There are no modifications needed to your vehicle, BUT a vacuum guage is a helpful learning tool, plus they look cool and give the impression that you know what your doing and we can all use that.

Disclaimer: I don't take any responsibility to any harm done to yourself or your vehicle. I have done and performed the following operations daily. They are safe.

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Step 1: Essentials

For this to work you'll need a few things:
Vehicle with an operational engine
Vacuum Gauge (Highly recommended)
Willingness to learn (this is no problem with the instructables crowd)

This method works for Electronic Fuel Injected and Carburetor engines. Also with Automatic and Standard transmissions.

Step 2: Let There Be Savings

Upon entering your vehicle you will most likely start the engine and shift into a gear and get onto the street. Your not running late so you think 40 mph will be a good cruising speed. What you will do is accelerate, firm and fast, until your vacuum gauge is somewhere between 10 and 4. Stay in that range until you reach 38 MPH, release the throttle and allow the vacuum gauge to travel back to, or close to, your idling pressure. By now you should have coasted to 40 MPH. You are going to want to maintain that speed. So, depending on your engine, find that sweet spot that is close to your idling speed, but also able to maintain 40 MPH. The key to this is finding the correct amount of throttle and then not moving the throttle at all, unless you need to stop.

If you managed to do all of the above without causing a ten car pileup, congratulations. However out in the distance, say 500 ft away, you see a light turning from a beautiful green to awful yellow. Using your sense of reasoning you realize that it will turn red before you reach it, meaning you'll have to (or should) stop. So what your going to want to do is release the throttle and shift into neutral, and coast right up to the red light. The same goes for stop signs. IF DRIVING AN AUTOMATIC BE CAREFUL NOT TO SHIFT INTO REVERSE you'll break your transmission

Step 3: Building a Relationship With Your Vehicle

Even 4000 lbs. of metal with 25 gallons of liquid explosive has feelings, so get to know your vehicle. It may not go for the quart of ice cream when misunderstood, but it will guzzle gas down to take care of the problem, and that can be bad for the enviroment and expensive. So to save you the trouble I've compiled a checklist of "relationship milestones" to help you and your vehicle to function efficiently.
1. You've probably heard this countless times but having properly inflated tires and the correct amount of lubricating and cooling fluids will increase mileage and part life.
2. Get the idling pressure. It should be around 20-23. You'll use this as a reference to know if your driving efficiently.
3. Anticipate stops or other obstacles that would disrupt your path.
4. Do the speed limit or close to it. Most vehicles cruise most efficiently around 40 mph. Remember every 10 mph over 65 mph can decrease your gas mileage by 15%.
5. Avoid aggresive driving, try to stay smooth and steady.

Step 4: Practice

This may seem difficult at first, but in a short amount of time you'll master it. Remember to take care of any problems with your vehicle, make sure its catalytic converter is functioning properly, and anything else you think needs looking into. And in no time you'll be feeling light-headed from the increase in air quality and cash in your wallet. Drive safe

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    59 Discussions


    8 years ago on Step 2

    shifting into neutral is also bad for automatic transmission it can damage drive gears causing problems earlier

    8 replies

    Reply 7 years ago on Step 2

    Is it? I've been shifting into neutral on my automatic transmission for a while now with no ill effects, but I'll stop if there's sufficient evidence to support your claim.

    Do you have anything besides anecdotal evidence to share? If so, that's something that would add a lot to this discussion. If not, that's okay too.


    Reply 7 years ago on Step 2

    it can damage the flywheel because no matter what it won't stop spinning and unlike a manual you can't clutch to seperate it from tranny before shifting back
    and can hit weaken the flywheel I personally haven't had a prob but just to forworn you


    Reply 1 year ago

    There is NO flywheel on an automatic transmission's engine. It is a FLEXPLATE.


    Reply 1 year ago

    It is also ILLEGAL in many places to shift into neutral and drift, because you no longer have full control. IF there is an emergency where you have to accelerate it now take more time.

    Project Dwilgubeast

    Reply 5 years ago on Introduction

    It's long-standing knowledge in the auto repair industry, in which I work, however there is, as ever, debate on the subject. But regardless, coasting an automatic in neutral saves you nothing. The unloaded engine uses more gas to maintain idle than remaining in gear with your foot off the throttle. The way fuel injection works, deceleration at closed throttle calls for less fuel than maintaining idle. To coast to a stop in neutral is a false economy. Especially since you are eliminating the ability to react in an instant to an emergency situation. I strongly, strongly recommend against coasting in neutral.


    Reply 7 years ago on Introduction

    Doesn't really matter there is evidence or not.on if its bad for the gears- if your aim is to save gas then you DON'T shift to neutral while coasting in an automatic. The reason is that most cars idle at a lower speed while in gear than they do out of gear. Next time you are sitting with your car parked look at the rev counter and watch it drop when you put it into gear. For that reason you are using more gas in neutral as opposed to in gear.


    Reply 6 years ago on Introduction

    well that's because it's under load when its in gear. The computer on many cars will actually accommodate for that and give it more gas to maintain rpms(so it won't stall out), And........ It always matters if there is evidence or not. Always....


    Reply 7 years ago on Introduction

    Well, I have some evidence to share regarding this discussion that you should be aware of. Three months ago, my Honda Automatic Transmission died along a highway in the middle of nowhere as luck would have it.
    Since owning the car for 80K miles, I have been putting it in neutral when going downhill on steep hills in order to save money on gas.
    I figured that I could save some gas money and get higher MPG if I shifted my Automatic into neutral, and coasted downhill, and then shifted back into gear when I reached the bottom of the hill.
    Needless to say, after doing this for 6 years or so, my transmission started to smoke and slip out of gear, and then it quickly and unexpectedly died in the middle of no where, to my shock and surprise!
    Coasting downhill in neutral and then shifting back into gear destroyed my Torque converter, and so the entire transmission had to be replaced.
    Take it from someone who knows better now- NEVER take your car out of gear for any reason. NEVER coast downhill to try to save money, because you won't.
    In a silly attempt to save a few dollars on gas, I ended up spending a whopping $3500 dollars on a new transmission.
    Spending $3500 dollars to save $10 doesn't make any sense, so take it from me- don't do it. Keep your transmission in gear at all times no matter what.


    6 years ago on Introduction

    Interesting, I installed a vacuum gage way back in the 70's during the gas crisis. All for them, but I hadn't seen one in years so I thought the gauge manufacturers had given up on them.


    7 years ago on Step 2

    Also, modern cars with automatic transmission will typically just not allow you to shift into reverse if you're moving above a certain speed. close to 10mph in my experience. if you try it'll just kick into neutral and kill the car.


    9 years ago on Step 1

    does this work only for petrol cars or would it work on diesels also.
    i would like to get the mpg up on my nissan x-trail turbo diesel.
    p.s how easy is it to fit vacuum gauges.

    1 reply

    Reply 9 years ago on Step 1

    It works with diesels, but I'm unsure as far as vacuum gauge installation difficulty is on diesels.  You might also want to look into waste oil as fuel.


    11 years ago on Introduction

    I can't seem to find a vacuum gauge on the internet at any of the auto parts sites. Are they ever called something else?

    3 replies

    Reply 11 years ago on Introduction

    its called a boost gauge....for nowadays or in professional terms as the next listing.....a pressure/vacuum gauge


    10 years ago on Step 2

    Most automatics have a button you must depress to shift to reverse or park, but not neutral. As long as you don't press it, you don't have to worry about shifting into reverse accidentally. In order to maximize fuel saving, SHUT THE ENGINE at long stop lights. It is a common myth that it takes more fuel to start than you save by not idling. This used to be true in large carburated engines. Almost all modern vehicles are fuel injected. If you will be stopped more than about 30 seconds, you will save gas by having the engine off (the exact time may be less or more depending on the vehicle)


    11 years ago on Introduction

    please excuse my ignorance but where do you connect the pressure gauge. what actual pressure are we testing. how the hell did this instructable get hijacked by pro/anti environmentalist fanatics i scanned these comments and even saw a reference to 9/11 what the what the


    11 years ago on Step 2

    only thing is about the shifting into neutral...doing this does not save gas it actually is worse than leaving it in drive(at least in newer cars 2000 and newer)
    Reason is that as your car coasts in drive the computer turns off the fuel system and continues to run the car(climate control, alt, especially the power steering, ect.) using the forward motion of the car. if you switch into neutral then the car is still using gas to power these things. and as most people who know about mpg saving strategies know that if you idle for more then 10 seconds then its usually more efficient to turn your car off...well imagine either coasting using no gas for 10 seconds or coasting using whatever amount of gas needed for idle!