Fleetguard Fields a 600,000-Mile Coolant

By Larry Stewart, Executive Editor | September 28, 2010

Fleetguard's ESXtreme is the company's first extended-life coolant formulated with organics. The ethylene-glycol coolant contains no borate, phosphate, or silicate, and protects heavy-duty diesel engines from corrosion for a minimum of 600,000 miles or 12,000 hours. According to Fleetguard, organic acids and nitrites prevent corrosion and liner pitting, and eliminating so many other additives reduces dissolved solids that can cause scale and wear out water-pump seals.

ESXtreme joins ES Compleat in Fleetguard's product line. ES Compleat is a hybrid long-life coolant that uses organic acids and also conventional inhibitors and reduced total dissolved solids to achieve service intervals of 150,000 miles or 4,000 hours.

Nearly 10 years ago, Texaco challenged traditional coolants containing nitrite and molybdate and a host of other minerals by launching a marketing effort promoting antifreeze that relies on organic acids to extend the coolant's durability with minimal service. Maintaining these organic-acid coolants (including Fleetguard's and Texaco's) requires changing the filter and pouring a bottle of booster chemistry into the radiator every 300,000 miles or 6,000 hours. Eventually, Caterpillar puts its own label on the Texaco long-life product. Detroit Diesel and Mack approve use of the coolant in their engines today. Chevron, which recently purchased Texaco, markets its organic-acid product as Delo Extended-Life Coolant. Zerex and Prestone have marketed similar products.

But Cummins had some problems with the organic-acid additive chemistry reacting with silicone gasket material. In a limited number of N14 engines whose radiators were filled with the Texaco product at the truck-maker's factory, some rocker-box seals allowed coolant leakage after 80,000 or 100,000 miles. Cummins recommended adding a one-time silicate supplement at the time of initial fill to stop the leaks, but continued to recommend against using Texaco's organic-acid coolants in its engines.

The benefits of a long-lived coolant with infrequent service intervals have enticed the trucking industry, though, and Fleetguard set out to develop a product that its parent company, Cummins, could rely on. ESXtreme is the result. It meets North American, European and Asian original equipment manufacturers' requirements for extended-life coolants. It also meets the performance requirements of ASTM, TMC, SAE and GM specifications.

"It is easy to use—simply charge the cooling system with ESXtreme, top-off with ESXtreme Premix, and after 300,000 miles or 6,000 hours, recharge with a quart of ESXtreme Extender and add an ESXtreme ESI coolant filter," says Dave Brisk, coolant product manager for Fleetguard. "You are then good to go for another 300,000 miles or 6,000 hours of operation."

Less-frequent cooling-system service reduces the opportunity for mistakes that can lead to dangerous over-concentrations of additives, which can cause overheating and engine failures. It also reduces service labor, which can quickly repay the coolant's higher cost.

Fleetguard says its ESXtreme can be used with the Chevron/Texaco long-life products, and that it is compatible with conventional antifreeze and supplemental coolant additives. It will cool and protect against corrosion, but diluting any organic-acid coolant with conventional chemistry will reduce the product's life expectancy. Fleetguard's test strips can be used to check the new coolant's liner-pitting protection (its nitrite and molybdate content), but the strips do not indicate the concentration of organic acids.

The new coolant is sold in both premix and concentrate formulas, and it is available in bulk, 55-gallon drums and one-gallon bottles. Fleetguard expects ESXtreme to be priced competitively with Chevron/Texaco's long-life product, and about 25 percent per gallon more than Fleetguard ES Compleat.