Back in 2004, several automakers got together to create a more pure form of gasoline to meet strict standards set by the U.S. Environmental Protection Agency (EPA), now known as Top Tier gasoline.

Before lower-grade gas pumps can be used again, companies like Tank Cleaning Industrial will have to clean them out.

While carbon buildup happens on essentially all engines, gasoline, diesel, N/A, or boosted, it's an increased concern in GDI engines. Standard Electronic Fuel Injection features injectors higher in ...