At very cold temperatures the German Castrol Syntec 0W-30 is thinner than a 5W-30 or 10W-30 motor oil. The German Castrol 0W-30 will be thicker than most 30 weight motor oils at high temperatures because the High Temperature High Shear Viscosity must be greater than 3.5 cP @150 C in order for it to qualify for the European ACEA A3/B3/B4 specs.
The technical data for the German Castrol Syntec 0W-30 is similar to the technical data for Mobil 1 0W-40. The "GC" 0W-30 is a thick SAE 30 viscosity. The OEM specs these oils meet are also similar.
[ October 29, 2003, 07:35 AM: Message edited by: Sin City ]