The winter coolant risk isn’t just freezing
For commercial vehicle workshops, winter coolant preparation is not only about checking the level. It starts with ensuring that the system contains the correct coolant chemistry for the vehicle or engine.
Commercial vehicle cooling systems are specification-led. Across a mixed fleet, different engines may require different coolant technologies and inhibitor packages, defined by their respective manufacturer specifications. That makes one of the most familiar workshop shortcuts increasingly unreliable: selecting coolant by colour.
Colour is an identifier — not a specification
There is no industry-wide relationship between coolant colour and coolant technology. Similar-looking products can use different inhibitor systems, while coolants of different colours may satisfy similar applications. The correct starting point is therefore the vehicle or engine manufacturer’s specification.
This is particularly relevant when topping up a vehicle with an unknown coolant history. Mixing incompatible formulations can dilute or disrupt the inhibitor package and reduce the protection expected from the coolant.
For workshops managing multiple brands, controlling which coolant goes into which vehicle is as important as having coolant available in the first place.
Freeze point only tells part of the story
When used with the correct scale for the coolant type, a refractometer provides a useful indication of glycol concentration and freeze protection. What it does not provide is a complete assessment of coolant condition.
Depending on the coolant technology and OEM maintenance regime, inhibitor levels, contamination, pH and coolant degradation may also be relevant. A coolant can therefore have an acceptable freeze point without necessarily being in suitable condition for continued service. This is why coolant condition, service history and manufacturer requirements need to be considered alongside concentration.
Heavy-duty protection goes beyond temperature
In heavy-duty diesel applications, the coolant also has an important role in controlling corrosion, deposits and cavitation.
Cylinder-liner cavitation, where applicable to the engine design, can progressively pit the liner surface if the coolant does not provide the required protection. Modern heavy-duty coolant specifications therefore address considerably more than freeze and boil-over performance.
The implication for the workshop is straightforward: “antifreeze” is not a universal product category where one formulation can automatically replace another.
Finol’s Cooltemp range of coolants and antifreeze reflects these differing requirements, with conventional, OAT, Si-OAT and hybrid formulations, including heavy-duty products and options meeting specific requirements such as Volvo VCS-2 and Renault Trucks RTCS-2.
For mixed fleets in particular, correct identification and specification-led selection can remove unnecessary uncertainty from coolant maintenance before winter arrives.
To view the Cooltemp range, scan the QR code above or for product selection and technical support, contact Finol Oils on +353 (0)1 223 8842, email fleet@finol.ie or visit www.finol.ie.
Always refer to the relevant vehicle or engine manufacturer’s specifications and service documentation before selecting, topping up, mixing or replacing coolant.