Introduction: Gain 20-80% Mpg Efficiency! Save $ on Gas. See How to Get 41.8mpg!

About: Hyper curious self-actualized Fitness + Car + Invention enthusiast. Teaching the world how to exercise 1 person at a time!
Hello fellow Instructables!

This write-up involves many simple fixes that can help you improve your fuel economy. I was able to get 41.8mpg in my little purple "Eggplant" car! The video shows you the results of my 150+ hours of teaching myself how to turn a cheap car into a Prius!

These particular fixes were used on my 1997 Ford Aspire 5 speed manual. I purchased this car for $900, put about $250 in parts into it, and a LOT of labor. We are talking roughly 150 hours of work/play/fun/stress/learning! (whatever you want to call it)
The full list of repairs and upgrades is at the end of this writeup....

The best way to work on any vehicle if you choose to do so:
- have supervision (safety)
- use proper jacks and jack stands
- have your car repair manual (I use Chiltons and Haynes)
- watch Youtube HOW TO videos on your car make/model/year to get the idea of how to do it!
------- If you do not have the tools, manuals, know-how, or supervision PLEASE TAKE YOUR CAR TO A PRO!

I list the fuel economy fixes from EASY to HARD below:

EASIEST - Buy a smaller/lighter vehicle
1. Do you really need to drive that 3 ton SUV?


1. check tire pressure (many people NEVER do this)
2. inflate tire pressure to 36PSI (CAUTION - Check PSI max listed on tire, ensure the max PSI is more than 36! NEVER overinflate tires) **This step will cause less rolling resistance**


1. Assuming you drive local and have GOOD tires on your car, you can lose the jack and spare tire. These combined probably weight roughly 40-60 pounds (varies per vehicle)
1A. Remove your rear seat (if you have a vehicle that will allow this)
2. Less weight = less gas required to move your vehicle.
3. CAUTION: I only suggest you perform this step if you trust your tires and/or have a AAA Car Club or some kind of tow/repair service membership!


1. pop hood, undo 2-4 metal snaps, replace your old dirty air filter!
2. Simple! your engine can breath better! (think how nasty your home furnce filters get; same thing happens in cars)

EASY - Oil change (Professional at work shop)

1. $25-35 saves a LOT of money when you engine parts are well lubricated

EASY but costly - ALLIGNMENT (Professional work at shop)

1. Having your car properly alligned can make your car travel straight.
2. Straight driving causes less wear and tear on the tires and makes for a smoother ride!

Are you ready to get your hands dirty? If not, do NOT go past this section!
If so, pop that hood and lets go!

MEDIUM - EXTRA AIR INTAKE (aka "DIY ghetto cold air intake")

1. I have no clue if this helped, but it seemed to allow more air into the engine.
2. Remove factory air filter box (huge plastic piece)
3. Purchase flexible aluminum ducting
4. Use aluminum ducting to create an air flow from the front of your car to the air intake tube, bypassing the filter
5. CAUTION: Place some sort of filtration system in the air intake tube so loose deposits do not make their way into the engine!


1. The throttle body will get dirty on many cars. This happens with carbon deposits.
2. A dirty throtlle body will allow less airflow and can restrict engine performance.
3. Cleaning the throttle body involves removing the air filter box and the air tube that connects to the engine. (you may have to remove 1 or 2 wire attachments)
4. After you remove these tubes (normally plastic) you can use "throttle body cleaner" spray to clean the black gunk off of your engine. Be careful to not use too much as this can choke up the engine!


1. This part requires proper tools (spark plug socket, wrenches, etc)
2. 4 cylinder engines are easier to work on compared to 6 cylinder engines.
3. If you do not have the tools or are not sure what you are doing, pay a professional.
4. Chaning the spark plugs and wires will require patience, but is not difficult with the right tools.
5. This will allow for better/faster ignition in the cylinders and possibly more efficient fuel consumption

MEDIUM - FUEL FILTER REPLACEMENT - (Professional at shop)

1. Gas is dangerous!!!!
2. I suggest you have a pro do this step.
3. You can do it, as I did on my car, but you need a repair manual (like Haynes) to make that happen


Multiple people commenting below agree this is not a safe step. Please see a professional mechanic for any modification to your existing AC system.

Hopefully you were able to upgrade a few of your systems :) Now enjoy the savings at the pump!

The full list of fixes include:
- removed spare tire and jack
- removed rear seat

- removed A/C system and all components (The system was empty and had no pressure)

- removed rear seat belts

- removed windshield washer fluid container

- removed excess plastic from air intake (it was restricting air flow)

- added a "DIY air tube" from front bumper to air intake
- new spark plugs, wires, and distributor cap
- new O2 sensor (front)
- new fuel filter
- coolant flush
- new valve cover gasket
- cleaned the heck out of the THROTTLE BODY and INTAKE (using carb cleaner)
- inflated all tires to 37psi (less rolling resistance)
- replaced both tie rod ends
- removed the carpet and installed new carpet

With all of this work, I removed somewhere around 130 pounds of weight from the vehicle. Also, upgrading and replacing many of the (engine/exhaust) systems probably helped increase the fuel economy.

If you like saving money on gas and fuel economy improvements, my website below will help you save $1,000's at the gym! is my effort to share workout advice without making you pay the high personal trainer price! Free gym knowledge and videos! :)