With gas prices skyrocketing, there are some gadgets and modifications you can implement that will increase fuel efficiency and improve gas mileage. Some of the gas mileage devices on the market work great, and others are outright scams. I’ll show you some of the most popular offers and tell you which ones work and which ones are a waste of money.

1. The electric supercharger (failure) The electric supercharger is designed with the idea of ​​forced induction modifications such as belt-driven superchargers or the popular turbocharger running on exhaust flow. While the idea is great in theory, I have yet to see one with a motor capable of pushing air as fast as the motor is already consuming it. In other words, these tend to REDUCE airflow into the engine, which can not only cause worse fuel economy, but can also damage your engine by causing a rich fuel to air ratio! Dyno testing on a 1998 S-10 V6 indicated a LOSS of 7 hp and an average loss of 3 mpg.
2. Vortex generators (poor) Here is a product that I have had marginal success with. The “Turbonator” and similar imitation products basically cause a twisting motion in the air intake hose, which in most cases allows air to travel faster to the intake manifold. They are easy to install and work to a certain extent, but in my tests I noticed a maximum increase of 3 horsepower and no noticeable difference in gas mileage on average, which is well below projected results. Because it’s so quick and easy to install, I’ve tried it on 5 different vehicles with similar results on each.
3. Performance chips (good) There are several performance chips available that can not only add horsepower to your vehicle, but also improve gas mileage. These work best with gasoline engines and high performance diesel engines. I have nothing bad to say about performance chips other than they can be quite expensive and will usually require installation and dyno adjustment by a professional performance shop, which in itself can be quite expensive. That said, they DO work. The power increase is the most noticeable with these, but they average about a 3-5 mpg increase.
4. Magnetic fuel conditioners (failure) These inexpensive devices can be had for around $10 and will do absolutely nothing for your gas mileage. It would be so much better if you put that $10 in your gas tank. This is an extremely small device that basically straps into your fuel line and should magically get you better fuel efficiency. The idea is that perfectly placed neodymium magnets will line up the fuel molecules and “overcharge” or “ionize” them. Scientifically speaking, that doesn’t make sense! If you’re curious, feel free to try, but these have Bruce’s thumbs up!
5. Mass Air Flow Module (Fault) There isn’t really a common name for these, but they are usually a very small box with a couple of cables available from various places online for $5-$15. The basic idea is that you’ll connect this to your Mass Air Flow (MAF) sensor or Intake Air Temperature (IAT) sensor, and trick your car’s computer into thinking that the air going into the engine is more colder than it really is. This is done using nothing more than a resistor that you can buy at Radio Shack for less than a dollar, and that’s it! It DOES work in the sense that it fools your computer, but it does not improve fuel economy NOR power output from general tests. Don’t fall for this one like my friend did!
6. Hydrogen cells/water cells (excellent) Why excellent? Most people report results of 20-45% increases in fuel efficiency. These work by splitting water into “HHO gas,” which is basically hydrogen and oxygen separated from each other. The only drawback is that there are really no production units available. Most HHO enthusiasts built their own setups. Fortunately it’s not terribly complicated and can be done at a fairly reasonable cost. There are some great plans available that show you exactly how to set this up for your car. I’ve also personally tested this setup and was able to almost double my fuel economy on the highway and triple my MPG in the city!

I hope my review of the various Gas Mileage Devices has helped you avoid some bad deals on the internet and beyond.