The claim that aftermarket car parts can increase fuel efficiency is, in many cases, suspect. The ever-growing costs of driving are pushing many consumers to seek out inexpensive add-ons in the hopes that they will positively affect fuel efficiency. Businesses have responded by offering numerous fuel additives and aftermarket devices that guarantee fuel savings, but many do not deliver as promised. More than that, tampering with a car’s emission system is punishable by hefty fines. The EPA will test aftermarket devices for their effectiveness, but only after a product has been submitted to them through the proper channels.
Some of the devices offered that claim to improve fuel efficiency include aftermarket exhaust parts such as special mufflers, catalytic converters and exhaust tubing. The idea behind aftermarket exhaust parts is that they help to increase fuel efficiency by easing pressure on pistons resulting from exhaust fumes, flowing backwards into the combustion chamber of an engine. Aftermarket intake parts, on the other hand, claim to be less restrictive in terms of the amount of air allowed to flow into an engine. At each point of air intake, less effort must be made by the engine, culminating in greater performance and reduced fuel consumption. Cold air intake systems are one example of this type of aftermarket device.
Not only is tampering with a car’s emission system technically a crime, it can also have lasting effects on the vehicle. That is not to say that the installation of an aftermarket device constitutes tampering. However, if done improperly, installing an intake or exhaust device could:
Some devices claim to separate the hydrogen from the oxygen molecules in water, creating a combustible gas (hydrogen) that is self-fueled by the oxygen. Installation of such a device may qualify as tampering, specifically if the air-to-fuel ratio must be adjusted. Moreover, there is no authoritative proof that this technology works in any way to increase fuel efficiency. Devices that are designed to alter the composition of any part of the fuel line have not been shown to positively affect fuel efficiency, and their installation, too, will likely be considered tampering.
With aftermarket devices, this is a problematic question. Any manufacturer offering an aftermarket device designed to improve fuel economy has a vested interest in claiming that it works. When put to rigorous and impartial testing which they more often than not aren’t, the results indicate that they don’t work. If they do work, there is the chance that the device’s installation is itself illegal. Cold air intake systems can improve engine performance, just as aftermarket mufflers or tailpipes can make exhaust more efficient. Improvement of fuel efficiency might be a gimmick used to sell the parts.
The best ways to improve fuel efficiency have little to do with added parts. Proven methods include keeping tires properly inflated, avoiding idling, tending to routine maintenance, observing the speed limit and minimizing unnecessary weight and aerodynamic restrictions.