I read through a huge long article on engine oils today - was more aimed at high performance than old V-8's but it had some interesting info and lab test results but damm nearly 50 pages poorly formatted on web was a brutal read.

For that application diesel type oils are not optimal, technically even for us but I like the detergent qualities - my oil stays clean much longer now than when I 1st bought my Disco.

If you want to read through it Motor oil testing