the owner of my old vortex used amsoil in it since about 15,000kms he brought the car new in 1986. i got the car in about 2004? and the engine and turbo was fully original and had done all most 300,000kms with nothing being done 2 motor in all that time. so i think it did its job. dad also uses the heavy dutie grease they make in his classic and prewar and dose the job very well
