When most people think of aftermarket suspension components, particularly new springs, it's usually in the context of improving handling. However, performance-oriented suspension components can also have some positive, if unintended, consequences for fuel efficiency. Higher performance springs are typically shorter than original equipment units, which means the body ends up riding lower on the wheels. Lowering the body reduces the frontal area of the vehicle which, when multiplied by the drag coefficient, reduces the total drag for the vehicle.
One of the leading manufacturers of aftermarket suspension components is Eibach and its Pro-kit springs are typically one inch lower than original parts. When installed on a 2010 Chevrolet Camaro SS with no other changes, test drivers improved real world fuel economy from 23.3 miles per gallon to 26.4 mpg over a 168-mile drive loop in California. That's a substantial difference but it also comes at the price of a much firmer ride, something many drivers may not appreciate. If you live somewhere where the roads are smooth, the $300 cost of the kit may be a worthwhile investment to save some fuel.
[Source: Detroit News]