YOOPYJ:
Wal-Mart has Mobil 1 with a yellow cap, 5w-40. It's suppose to be a suv/diesel oil. Wouldn't this be better for motorcycles...like a 1985 Goldwing? TOJ [/QUOTE]
The 5W-40 yellow cap SUV oil is Delvac 1.
Among other things it has a slug of magnesium in it, which other Mobil 1 oils do not, to control soot (it's a detergent). Comparing it to Mobil 1 MX4T 10W-40 Motorcycle oil:
SUV Flash Point (ASTM D 92) °C 226
MX4T Flash Point (ASTM D 92) °C 253
SUV Pour Point ASTM D 97 ºC -45
MX4T Pour Point ASTM D 97 °C -54
There's a slight chance the magnesium could lead to spark plug fouling (which is no problem in a diesel) and the dedicated motorcycle oil possibly exhibits better low and high temperature performance.