While greater performance is often times the driving force behind the purchase of aftermarket parts, they can also be a great way to improve gas mileage in a vehicle at the same time. While this improved mileage may not occur with all aftermarket parts, there are a few that can have a marked effect on a vehicle’s fuel economy. By taking advantage of these parts, you can improve both power and efficiency at the same time.Change your Fuel and Ignition Settings
The amount of fuel and degree of ignition timing that allows your engine to function is dictated by the vehicle’s ECU or electronic control unit. While the factory does its best to encrypt or otherwise prevent owners from tampering with these values, there are a variety of performance chips and programmable ECU’s that can be installed to allow a custom tune to be installed on a vehicle. While adding more fuel and air is generally how more power is made, having too rich of a fuel mixture can hurt power figures and dull response. By leaning these mixtures and advancing ignition timing, power and response can be improved, while at the same time reducing fuel consumption by noticeable amounts.Reduce your Vehicle’s Curb Weight
One of the easiest ways to improve all around vehicle performance is by lightening the overall weight of a vehicle. Composite body panels, performance suspension and lighter, more durable wheels and brakes all contribute to a lighter vehicle, which in turn is less work for the engine to accelerate up to speed. An engine that has to work less is an engine that uses less fuel. Just as hauling excessive loads around town can reduce fuel consumption, removing large amounts of weight can greatly improve it, all with little to no downside.Install an Underdrive Pulley Kit
Underdrive pulleys function by literally slowing down pulley driven accessories such as the power steering, water pump, alternator and even the air conditioner. By reducing the amount of power these accessories require to run, you can free up power from the engine that is otherwise lost to parasitic drive losses. While these can add marginal power increases to your vehicle, they can also help to mildly improve fuel economy. Because the engine now has more available power to draw from without having to add any additional fuel, the engine can get up to speed with less effort, which in turn consumes less fuel. Aftermarket parts that improve power by increasing efficiency rather than increasing air and fuel, should almost always help improve fuel economy as a side effect. By improving the efficiency of an engine, and the amount of mass it must accelerate up to speed, you in essence reduce its work load, and fuel consumption is reduced. Combined with proper fuel and ignition timing changes, which free up power by reducing what is in some cases, wastefully over-rich fuel ratios, it is not unreasonable to expect gains of 3-6% fuel economy. Best of all, these gains come with increased speed and driveability, meaning you can enjoy your drive more, while consuming less.