The tip of the fuel-system spear, fuel injectors incorporate an electronically controlled valve and a nozzle that sprays fuel into each of an engine’s intake ports, or directly into its cylinders.

some older cars won’t, so look out for the aforementioned signs of backed-up injectors. You can’t usually see much of a fuel injector from the top of the engine, but here’s what one looks like.

Add to that the possibility of the injector rusting from the water in the fuel, and some byproducts from the ethanol, and ...

Barring electric vehicles, each and every vehicle needs some sort of combustible fuel. Until about four decades ago, almost every passenger car used a carburetor to handle its air and fuel needs.

In fact, some car manufacturers specifically recommend using Top Tier gasoline in owner’s manuals. Related: Do Fuel Injectors Need Periodic Cleaning? Carbon buildup became a bigger issue with ...