Antifreeze for the Mazda CX-5
The CX-5 is one of the most common imports of recent years and almost always arrives with a Skyactiv-G engine. That engine runs an unusually high compression ratio for petrol, so the aluminium head works in a hotter zone. Mazda is named on the Valvoline Zerex Asian Blue data sheet.
Photographs come from the manufacturer's official materials.
Cooling system volume (litres) roughly six to eight litres
High compression and the hottest spot
The higher the compression ratio, the more heat is produced in the combustion chamber and the more load falls on the cylinder head. Skyactiv-G is built on exactly that principle, since high compression is the basis of its economy.
The hottest point of an aluminium head is what the ASTM D4340 test examines. Valvoline Zerex Asian Blue returns 0.1 mg/cm²/week where the limit allows 1.0, a tenth of the permitted loss.
Deposits are especially harmful in that zone, because they act as thermal insulation and make the metal hotter still. This is precisely why Mazda calls for a silicate-free fluid.
The greenish factory fluid and the blue Zerex
Mazda's factory long-life fluid is greenish while our product is blue. The data sheet defines the product for vehicles requiring a blue or green, silicate-free HOAT, so both belong to the same family.
The correct approach is still a complete flush rather than topping up the old fluid. Once two different products are mixed, you can never tell what is in the system or when its service life ends.
One bottle yields 7.5 litres at 50/50. A CX-5 system holds six to eight litres, so two bottles are better for a complete flush.