Vehicle Modifications for Fuel Economy

There are a few modifications that in my experience provide better fuel economy and in most cases more power. There are also many modifications being touted that probably don’t work and provide minimal benefit in either power or fuel economy. I’ll cover the ones that I know work and have experience with. I’ll add others to this page based on feedback from the Gas Misers Community

High Flow Air Filters

This is simple and not very expensive. By replacing your stock air filter with a High Flow air filter you will gain additional power and more importantly will contribute to greater fuel economy and gains in the MPG you are getting from your vehicle. You’ll get the additional benefit of never having to replace your air filter as many of the high flow air filters, such as those made by K&N can be cleaned and recharged.

Cold Air Intake Systems

A cold air intake system is the next step up from replacing a stock air filter with a high flow rate air filter. Cold air intake systems replace the stock air intake systems on your vehicles, they typically involve a small chamber that insulates the air intake from the heat of the engine compartment, a High flow air filter, a replacement air tube that is usually designed to allow more volumes of air through it then the stock device.

The tube will usually have adapters on it for the mass airflow sensor plus any vacuum hoses that may attach to your stock system. A cold air intake system will give  you increased power and better fuel economy. I have used these systems on almost every vehicle I have owned over the last twelve years and am a firm believer that these systems deliver on both power and increased mpg.

These systems are somewhat expensive, starting at $200 and up for a quality system. Lately there have been a number of systems on the market from China and possible India that are significantly less expensive. Do your homework before purchasing any of these systems as a few of them do not have provisions built into them to replace the Mass Air Flow sensor. Here is a link to my 2003 ford Expedition CAI Project .

Performance Exhaust

Adding a performance exhaust system is probably one of the most difficult modifications that can be done but will also result in increased power as well as increased fuel efficiency. There are various systems on the market, the easiest to install are generally the axle-back or cat-back systems. Many of these systems are manufactured specifically for performance applications, my experience has been the mildly increasing performance, coupled with driving techniques will yield you better gas mileage and overall fuel efficiency. One drawback to adding a performance exhaust is the noise level. Although you’ll achieve better MPG you’ll also have a louder exhaust. For V8 engines the sound is actually pleasing. For 6 and especially 4 cylinder engines the sound can be harsh. I’m sure there are systems on the market that have less restrictive exhaust capabilities but are not loud or annoying. If you know of any please post in the forum and share it with us.

LRR Tires

Low Rolling Resistance Tires will help with overall fuel economy. Many new vehicles are sold with these type of tires already on them. Unfortunately the replacement market hasnt quite caught up yet but is getting there. MPG gains of between 3 and 4% can be achieved with these tires. The cost of changing your tires is a key consideration here, it probably doesn't make sense to change tires until your existing set are worn out, but when they are ready to be replaced, it would be a good investment to spend an extra amount for LRR type tires. Here is a link with interesting data on LRR Tires .

Other Modifications

There are countless other modifications claiming that they will help you save gas out there. They seem to spring up like weeds, some probably have merit and others may be a complete waste of money. I'll add them as readers provide feedback on them. One resource you should consider using if you are contemplating any of these devices is the EPA Website, Fuel savings devices, They have studies and test results on many devices which should be useful in your research.