I have an 00 CSVT with 11,600 and a 96 Mystique 5 sp., duratec with 44,000. I've just had the Mystique for several months. The previous owner ran Castrol Syntec. Its about time for an oil change so I went to my friendly Meijer store tonight and they had a great deal on gallon jugs of 5W50 Castrol Syntec. I've always used 5w30 on the SVT (conventional valvoline). I've never heard of anyone using 5w50 on anything. I always thought the bottom number on the oil was what mattered. Anyone have any opinions on 5w50 Castrol synthetic?
