Their product line and website is a bit convoluted. I know everyone raves about the 703 blend. Which one of their oils is full synthetic, and is it superior to the 7,000 series blend? Thanks.
The #156 is their 5w30 full synthetic, but we haven't really seen many UOAs on it to see for sure if it's worth the extra $$$. The #701 5w30 and #703 10w30 blends perform so well that there really is no need to go with the full synthetic Schaeffer Oil. Plus the full synthetic is not available in single quart bottles.