Five Car Modifications for Extreme Fuel Efficiency

Improving Cars for Greater Fuel Efficiency

Once a vehicle naturally reaches its limits on fuel efficiency, most people either resign themselves to their car's gas mileage or go looking for a replacement. For a dedicated few, however, the answer is changing the car.

Here are a few unusual modifications that can boost a vehicle's fuel efficiency and ecological friendliness, sometimes at the expense of storage space or weird looks from neighbors. Drivers who take on these kinds of modifications are voiding their warranties and risking damage to their cars, but they may be doing a lot less damage to the environment.

Covering the Wheels

Wheel skirts seem old-fashioned, but they were relatively common on many classic cars, usually as part of a streamlined styling package. More recent vehicles such as the original Honda Insight have used skirts to improve vehicle aerodynamics, however.

Some car owners seek to get the benefits that Honda included in the Insight for their own vehicles by adding DIY wheel skirts. These reduce turbulence around the back wheels of the car and make sure that airflow is smooth and uninterrupted. Most do-it-yourself skirt additions are for the back of the car, but a few extreme modification fans also add skirting on the front.

Reduce Turbulence and Radiator Airflow

By adding simple grille blocks to a vehicle, fuel efficiency enthusiasts can reduce the amount of turbulence around the front bumper and the hood. This relatively cost-effective modification also helps reduce the flow of air around and through the radiator.

In cold climates, this helps the engine reach its ideal operating heat much more quickly. In hot climates, grille blocks may not be the best idea, however; they can encourage the engine to overheat.

Removing the Mirrors

While taking the side mirrors off a car entirely isn't safe or legal, replacing them with cameras does provide some aerodynamic benefit. The car takes up less space and air flows better around it. The best cameras for this purpose are tiny wireless devices that transmit to a central screen, allowing drivers to see the sides and rear of the car clearly.

A cheaper alternative includes replacing the side mirrors with convex mirrors similar to those used to spot shoplifters in some stores, but smaller. These can be mounted on the inside of the front windows and functionally replace the mirrors.

Taking Weight Reduction to Extremes

Most people realize that they shouldn't haul around old camping equipment, tools or other heavy objects when those items aren't in use. A few people take weight reduction much further, though. Drivers who don't often take passengers with them have been known to remove the rear and sometimes front passenger seats in search of better gas mileage.

Some even go as far as to remove the vehicle's soundproofing, interior trim, audio systems and any other non-essential items. This is similar to the stripping procedure that race car drivers use to get the highest speeds and uses less fuel on acceleration. The downside is that the car may be less comfortable or extremely loud on the highway.

Adding a Boat-tail

Truly extreme modifications go beyond changing accessories or interior features; they actually redesign the vehicle body. Putting a boat-tail on a car changes its look entirely for the sake of improved aerodynamics. Boat tails prevent heavy turbulence behind the car, but they make it longer and potentially more difficult to park and drive in heavy traffic.

Even though a boat tail adds significant weight to the car, the aerodynamic gains are large enough to provide a big improvement in fuel economy. These are more impressive as the vehicle reaches high speeds, of course, since the engine works less hard to move a streamlined car at Interstate speeds. The gains are smaller for enthusiasts who choose to mount a small spoiler instead of a boat-tail, but spoilers tend to be cheaper, easier to install, and less peculiar-looking.