Your car's engine needs a very specific diet of air and fuel to do its job, and it's the fuel pressure regulator's (FPR) job to feed it the right amount. The gadget is relatively tiny and can fit in ...

For this issue's Tech Inspection, we added a Cagle fuel regulator to a daily driver. The Cagle regulator is different from most because it restricts fuel according to engine load (as read by engine ...