My smaller (original) 4215 8 row oil cooler was a the
new style, not the older and apparently poor perfoming model. I spoke with with Pacific Oil Coolers (
oilcoolers.com
) and they were the people who told me that the new model Positechs were much better than the old series, and roughly comparable in cooling to the S/W. I compared performance curves of the S/W and new Positech and they seemed to confirm that statement (note: I am not an engineer). If I remember correctly, you can identify the old style Positechs as they have more rows (vanes) than the new style. I have not test any S/W model coolers.