Quote:
Originally Posted by Rick Parker
patrickt:
The auto manufacturers lobbied the oil companies to remove the products within the oils and lubricants, specifically ZDDP and phosphorus that contaminate and ultimately "poison" the required catalytic convertors. They (the Auto Mfrs) are obligated to provide warranty coverage for the emission systems including the convertors for 100,000 miles. With these products in the lubricants they consistantly struggle to reach that point. But with a reduced (read altered) additives package they stand a better chance. Hence the reduction of these chemicals. These repeatedly bond to the metal and become a sacraficial barrier to prevent metal to metal scuffing friction associated with flat tappet cams (VS Roller type) and worm gears of which the cam and distributor are. |
I understand why ZDDP levels have been lowered. I do not understand why GM changed their EOS formula.