Good-Bye to the Green

Remember the green coolant that was poured into vehicle cooling systems? Many years back, everyone, from the shop technician to the DIY-obsessed car owner would grab a bottle of that green coolant and top-up the radiator. It was a one-size-fits-all solution and was the standard for many years.
As any shop technician knows, that is a thing of the past. One will be hard-pressed to find many vehicles today that will take the green-only coolant; and even harder to find that coolant, although you may still find some bottles being sold at big-box stores, possibly next to the discounted CDs of The Carpenter’s Greatest Hits.
There is a very good reason for that. Today’s vehicle cooling systems are complex and vehicle manufacturers now require specific coolant formulations for their systems. Putting the wrong coolant in a vehicle is asking for trouble. The challenge for a shop’s service writer and technician is explaining to the vehicle owner why that is the case.
Why you should never mix and match coolants
One of the persistent myths that vehicle owners often cling too are coolants are universal. In their estimation, all the stuff does is help keep the engine cool, so there is no reason to worry about what is put into the system. That myth is hard to dispel because some vehicle owners will mention some product that claims to be a universal coolant. It even says so right on the label. They may even tell the service writer or technician about a friend who uses the stuff all the time and they have never had a problem with their vehicle.
Dave Turcotte, technical director, OEM with Valvoline knows all about these ‘universal’ coolants, and despairs at the fact that such products are being sold under that pretext. The reality is, there is no such thing as a ‘universal’ coolant, and what is being sold to people is convenience.
The problem with such products is, over time, they will cause damage to the vehicle’s cooling system, from leaks to corrosion, each resulting in an expensive repair.
“We have fought this perception for years,” Turcotte admits. “It is like saying to a vehicle owner, “You can use one kind of transmission fluid in all vehicles, or you can use one kind of brake fluid or motor oil viscosity grade.’ It is simply not true.”
Turcotte says a bit of history might help vehicle owners understand what is going on, and why there is a range of coolants and coolant colours out there. Until 1994, that green coolant mentioned earlier was standard for all domestic vehicles. Then General Motors announced its new vehicles would require the use of a new coolant, Dexcool, an OAT coolant with a five year, 100,000 mile drain interval. Volkswagen soon followed in moving to OAT-based coolants. In 2001, Chrysler moved to using a hybrid coolant in its vehicles that also had a five year, 100,000 mile drain interval; and shortly after, Ford Motor Company also moved to a long-life coolant. Many European makers of vehicles also moved new kinds of coolants, with BMW, Mercedes and Volvo using hybrid coolants in their vehicles.
“All are based on ethylene glycol, but use different performance additives, for example, for corrosion control, defoaming, scale inhibition, etc.,” says Turcotte. “Green coolant is based on inorganic additives and is called IAT (Inorganic Additive Technology). It is generally fast acting and very protective, but (it) needs to be changed every couple of years. Organic Acid Technology (OAT), is based primarily on carbon-based molecules, typically organic acids, to protect cooling system metal. These fluids do not deplete in service, but may not protect quickly in fast corrosion conditions, like boiling, and may not protect solder. This makes them generally not backward compatible with older green coolant engines,
“Hybrid coolant, called HOAT (Hybrid Organic Acid Technology) uses both inorganic and organic, carbon-based additives for long life protection. The idea with hybrids is to provide excellent all-around corrosion protection and extended drain intervals.”
This is why it is important to carefully match the vehicle type to its recommended coolant. Think for a moment of motor oils. Today’s vehicles, especially many high-end domestic and European models, require specific blends of motor oils. Mismatching motor oils to a vehicle type will result, in some cases, to severe engine damage. The same goes for coolants, which is why vehicle owners have to be warned not to buy into the myth of universal coolants.
“European vehicles use phosphate-free coolants and the reason they specify that is they have had issue with phosphates precipitating out of the system,” says Dan Peterson, vice-president of technology development with Amsoil Lubricants. “When they do that, there are issues with scaling and deposits … which build up and can ruin a water pump and seals which then creates poor heat transfer as things build up in the small tubes in the radiator.”
“General Motors wants Dexcool,” adds Turcotte. “One should use only this for vehicle manufactured since 1994. Chrysler recommends fluids conforming to MS-9769, hybrid technology G-05. Ford recommends the HOAT and has gone so far as to put a ‘No Orange Coolant’ sticker on expansion bottles to prevent orange OAT from being added.”
Coolant makers also place right on the label information as to which vehicles and types the coolant is made for. This should be shown to the vehicle owner if they have any questions.
“Valvoline will launch two new antifreeze/coolant products for Canadian consumers. Zerex Asian Vehicle and MaxLife Antifreeze/Coolant will be available on retail shelves this fall,” says Karen Insko, marketing manager, non-lubricants, Valvoline. Vehicles manufactured from Asian-based firms make up one-third of Canada’s passenger car and light truck market.
To meet the needs of this growing segment, Valvoline’s Zerex Asian Vehicle Antifreeze/Coolant is specifically designed to meet the compatibility and chemical requirements of Asian vehicle manufacturers. These vehicles specify a silicate free HOAT formula with a phosphate additive to protect the cooling systems from rust and corrosion.
It is recommended for all Asian Vehicles (Toyota, Lexus, Scion, Honda, Acura, Nissan, Infiniti, Subaru, Mazda, Suzuki, Hyundai, Kia, Mitsubishi, Isuzu, Dae Woo and Daihatsu) and its meets or exceeds specifications for Hyundai/Kia MS 591-08, Mitsubishi ES-64217, JIS K 2234-1994, ASTM D3306, ASTM D4985, Ford WSS-M97B55-A, Federal Specification A-A-870A and is recommended for Toyota/Lexus, Scion, Honda/Acura, Nissan/Infiniti, Subaru, Mazda, Suzuki, Isuzu, Dae Woo and Daihatsu vehicles. The second product for the Canadian market is MaxLife High Mileage Antifreeze/Coolant with Alugard Plus.
Turcotte also recommends shops keep on hand two types of coolant, first Dexcool/OAT for General Motors, Saturn, Saab, Volkswagen and Asian vehicles; and an HOAT/Hybrid for new Ford, Chrysler and European vehicles such as Mercedes.