SHELLZONE Antifreeze Coolant. Shellzone Antifreeze is a superior quality, single phase, ethylene glycol based antifreeze. It is a low silicate, all-purpose coolant designed for use in both automotive and heavy duty diesel engines (with the use of SCA’s). Shellzone Antifreeze is specially formulated to meet the stringent aluminum corrosion protection requirements of today’s automotive engines.  Because of its low concentration of silicate, it also complies with Cummin and other heavy-duty diesel engine manufacture’s silicate requirements. SHELLZONE