Valvoline MaxLife High Mileage Complete Fuel System Cleaner

The brand claims it revitalizes injectors, pumps, and carburetors and restores lost engine performance for high-mileage vehicles. The active detergent is PEA (polyether amine), confirmed directly in the US SDS at 20-30% concentration, a stronger disclosure than many category peers, where the active is often only indicated from a secondary source. PEA-class chemistry credibly reaches fuel injectors and intake valves through the fuel path; no combustion-chamber-specific co-active is named in the disclosed ingredients, so the wider friction-reduction and full-system claims go beyond what the confirmed chemistry supports on its own.

The listing does not make a GDI or direct-injection claim at all. Its marketing language references injectors, pumps, and carburetors, which describes port-fed fuel delivery rather than direct injection. A tank-poured additive travels through the fuel path and cannot reach the intake valves on a true GDI engine, since fuel there is injected directly into the combustion chamber and never washes over the valves. Treat any GDI intake-valve benefit as unaddressed by this product.

The bottle is labeled specifically for gasoline engines. No diesel-compatible formulation or claim appears on the listing or label, so this product should not be used as a substitute for a diesel-specific fuel system cleaner.

The label states one 12 oz bottle treats up to 18 gallons of gasoline, added before a fill-up, with a recommended use interval of every 5,000 miles. That is a periodic-maintenance protocol rather than a one-time flush, and the label and brand messaging agree on the dosing.

Yes. Both the SDS (Section 15) and the physical bottle label carry a California Proposition 65 warning tied to minor aromatic components of the petroleum-distillate/naphtha carrier blend, even though the Amazon listing itself does not surface a Prop 65 flag.