Gumout Regane High Mileage Fuel System Cleaner

Gumout Regane High Mileage uses polyetheramine (PEA) — confirmed from the US SDS at 25–50% by weight, an unusually transparent disclosure for this category. PEA is the class with the most research on injector and intake valve deposit removal. Positioned for vehicles with 75,000+ miles; covers GDI and port-injection engines. Community evidence is positive but moderate: 659 Amazon ratings at 4.6 stars, no independent test data. Treatment protocol: one bottle per tank every 3,000 miles.

Best for higher-mileage owners running non-Top Tier gasoline who want a confirmed-PEA maintenance treatment for GDI and port-injection engines. Skip it if you consistently run Top Tier certified fuel — the OEM detergent package already does this job. Skip it for severe rough idle or hesitation; professional ultrasonic injector cleaning is the right call at that point.

SDS §2 is DANGER — H350 (carcinogen Cat 1B) and H304 (aspiration toxicant: hazard is swallowed liquid entering the lungs, not contact or inhalation at the pour). No skin, eye, or respiratory H-codes at mixture level. Do not induce vomiting if ingested — seek medical attention. The product combusts in the engine; exhaust byproducts are the environmental endpoint. The Amazon listing carries a Prop 65 warning; SDS §15 names a trace carcinogen ingredient as the basis.