PEAK Long Life 50/50 Prediluted Antifreeze & Coolant

Peak markets Long Life as compatible with 'all makes and models.' No named OEM spec document numbers (GM DEXOS, Ford WSS-M97B44-D, Toyota SLLC, VW TL 774-G, etc.) were found on the label, Amazon listing, or in any available technical data sheet as of May 2026. Owners of vehicles with strict OEM coolant specifications — particularly European vehicles (VW, BMW, Mercedes) or newer Asian OEM systems — should verify the correct specification from their owner's manual before using a generic OAT formula.

Ethylene glycol (EG). The SDS (Section 3) lists ethylene glycol at 90–97% by weight. Ethylene glycol is acutely toxic if swallowed — the H302 classification (harmful if swallowed, Cat 4) applies, and the product carries a California Proposition 65 warning for ethylene glycol (developmental toxicity). If you need a less-toxic alternative for a household with pets or children, propylene glycol-based coolants are materially safer on this axis.

Denatonium benzoate is a bittering agent added at 30–50 ppm to deter accidental ingestion by pets and children. Ethylene glycol has a mildly sweet taste that can attract animals; denatonium benzoate is one of the most bitter compounds known. Its presence is disclosed on the Amazon listing feature bullets ('Product contains bittering agent - denatonium benzoate'). This additive meaningfully reduces palatability but does not alter the H302 toxicity classification — the product is still harmful if swallowed.

Peak claims 5 years / 150,000 miles when a complete cooling system flush and fill is performed (not top-off use). The 5-year portion of this claim is consistent with OAT inhibitor chemistry, which degrades more slowly than silicate-based (IAT) coolants. Independent used-coolant analysis (VOA) data specifically corroborating the 150,000-mile portion of the claim is limited in public community forums (BITOG) as of 2026. Standard guidance: test your coolant's pH and inhibitor reserve at 3-year intervals rather than relying solely on the label claim.

No. Ethylene glycol coolant — used or fresh — must be collected and brought to a recycling program. Most auto parts stores (AutoZone, O'Reilly Auto Parts, Advance Auto Parts) accept used coolant at no charge. Storm drain or ground disposal is prohibited under the Clean Water Act in most US jurisdictions and causes documented harm to aquatic environments and wildlife. The sweet smell of EG also attracts animals, increasing the risk of ingestion if spilled or left in open containers.