ARCO on Spring Street in La Mesa dispenses TOP TIER-certified gasoline through the PROclean additive package, a detergent formulation that exceeds EPA minimum deposit-control requirements across all octane grades. The station's on-site car wash and ampm convenience mart share a 0.82-acre parcel near the Interstate 8 interchange, a Spring Street corridor where vehicle-appearance services also include the express tunnel at Soapy Joe's Car Wash on Jackson Drive. Regular unleaded and diesel are pumped from islands equipped with propane-exchange cylinders, and the Grossmont Center retail hub sits less than half a mile north along Fletcher Parkway. Drivers maintaining TOP TIER fuel consistency between scheduled maintenance can complement that deposit prevention with the engine diagnostics at Greg's Automotive farther east on University Avenue. The TOP TIER performance standard caps average intake-valve deposits at 50 mg under ASTM D 6201 dynamometer protocol and prohibits organo-metallic additives known to degrade oxygen sensors and three-way catalytic converters in modern emission-control systems.