Shutterstock // Setta Sornnoi Over time and miles, your car might start to slow down. It might not accelerate as quick ...

The first thing you should understand is that direct-port, constant-flow fuel-injection—Hilborns, En-derles, Crowers, whatever—were never designed, nor intended, to be run on the street. All of these ...

Over time and miles, your car might start to slow down. It might not accelerate as quickly as it once did; the engine may not run as smoothly as you remember, or the fuel economy may dip—but ...