Equipment

what's new in: Coolants

March 1, 2008

The hotter-running engines resulting from '07 emissions reductions efforts have spurred the growth of extended life coolants (ELC) in the U.S. to meet new heavy-duty cooling requirements. Most coolant manufacturers now offer some type of ELC product. Carmen Ulabarro, coolant marketing-Chevron, says the most recent trend is toward nitrite-free ELC. In fact, Detroit Diesel will only be recommending

DEBORAH MCGUFFIE-SCHYHOL

Carmen Ulabarro, coolant marketing-Chevron, says the most recent trend is toward nitrite-free ELC. In fact, “Detroit Diesel will only be recommending the use of OAT (organic acid technology) ELC, along with fully formulated coolants that are phosphate-free and meet the chemical requirements of ASTM D6210,” he advises.

“There seems to be a lot of focus on heat dissipation [with the new '07 engines],” Ulabarro reports. “Though this is very important, the newer engines are also coming in with more aluminum in them, and that may actually be more of a driver than heat as to what coolant technology is needed going forward.”

Aluminum, Ulabarro explains, has been shown to be a very difficult metal to protect in high heat areas, which, in great part, is why ELC was introduced in the U.S. During the last two years, according to Ulabarro, Chevron has released two new coolants to the heavy-duty market. “The most recent is our OAT ELC (Delo Extended Life Coolant/Antifreeze Nitrite-free and Texaco Extended Life Coolant/Antifreeze Nitrite-free). The other is our heavy-duty, phosphate-free, conventional-type coolant.”

David Perry, tech services and product support manager for BP Lubricants, says that although about 26% of truck fleets still use “green” conventional coolants, the trend is changing. “We see two transitions. First, those that have been using ‘green’ coolant and adding SCAs (supplemental coolant additives) are switching to coolants like our Castrol Heavy-Duty Antifreeze with SCA, or Castrol Premix Antifreeze with SCA already contained in the product.

“Second, fleets that have been using the SCA pre-charged coolant are now switching to the extended life organic acid coolants like our Castrol Heavy-Duty 50/50 Pre-Diluted Extended Life Coolant/Antifreeze, which is also nitrite-free.” According to Perry, BP Lubricants estimates that 32% of fleets have switched to extended life technology.

Mike Sarris, director of global coolants and chemicals for Cummins Filtration, agrees there's a clear trend in the industry toward the use of extended life coolants. “They allow fleets to extend coolant service intervals and simplify maintenance while still providing the level of protection needed for heavy-duty diesel engines.” Cummins' flagship product, Fleetguard's ES (Extended Service) Compleat, is a fully formulated antifreeze that can last the life of the heavy-duty engine when properly maintained.

Shell Lubricants' Stede Granger, OEM technical services manager, explains that what makes conventional antifreeze/coolants and the newer extended life products so completely different is the additive package. ELCs, he notes, contain organic additive (or acid) technology, which keeps working to protect engines longer. Granger says that even after 600,000 miles of truck operation, 90% of the additives in ELC will still remain in the coolant, unlike conventional products where the additives get depleted much earlier.

Another difference is that while conventional coolants must include an extra substance called nitrite in order to prevent liner pitting in the engine, the core chemistry of OAT protects against this phenomena.

Later this year, Granger reports, Shell will be releasing an improved version of its extended life coolant — Rotella Ultra ELC, which will be nitrite-free. “We've done a tremendous amount of testing and working with OEMs as well to get it approved.”

Penray's director of marketing, Chris McKenzie, says the key with today's hotter running engines is regular cooling system maintenance. Penray, he reports, offers fleets the 3-Way Universal Test Strip, which allows technicians to quickly determine Pass/Fail for ELC. It also tests freezepoints and nitrites for conventional coolant.