Engine Modifications and Auto Warranty Coverage
Increasing the performance of a vehicle is one of the ways that owning a car can be a lot of fun. Adding high-performance components such as better headers, fuel injection systems and so forth can make a vehicle faster and more powerful and, sometimes, these after-market parts are of a higher quality than those recommended by the vehicle's manufacturer. When a car is under warranty, however, there may be specific limitations on the amount of "modding" that may be done to a vehicle while still keeping it under the terms of the warranty.
Most warranties are written with a set of conditions that ensure that the vehicle will perform at the highest level of reliability possible. For mechanics, this usually means that the vehicle is equipped with only manufacturer-recommended replacement parts and accessories. While the aftermarket parts may be of a higher quality, they're still produced for a range of vehicles, not a specific vehicle and their operating characteristics may not be in line with manufacturer recommendations. Thus, installing these parts will sometimes void the warranty coverage as the part can always be blamed for the failure rather than a flaw in the vehicle's manufacture.
Aftermarket parts are usually available from auto parts stores and from online sources. They're often either imitations of or the actual components used by mechanics who service vehicles that compete in races and other events. While these components may increase the performance of the vehicle, they may also cause it to operate at a level not intended by the manufacturer. A family sedan, after all, is not designed to be a fast vehicle with very rapid takeoff characteristics. While it can be made as much with the addition of the right parts, this will usually make the warranty useless and may well damage the vehicle.
Ask the dealer what modifications are fair game. Generally, tweaking the engine to get a few extra horsepower or modifying the drive train to get extra torque will void the warranty. For the warranty period, it's best to have any servicing done by the original dealer so one can be assured that only approved parts are used to replace those that may wear out with normal usage. Dealers can be more expensive than regular mechanics, but the warranty coverage may well be worth thousands of dollars if something cataclysmic should happen to the vehicle during use.
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