Just a few thoughts:
ZDDP won't prevent plastic from aging. Chain ramps are made of plastic.
ZDDP will always harm your catalysators. It's not a matter of the amount in the oil.
So DT 40 was designed to be changed every 6 months or less than 5 K miles. Nice cash cow.
Are there alternatives? There are ester based fully synthetic oils - for example Motul 300V - out there that can be used for 12 months and more miles that don't harm any catalysators, but have a maximum sheer stability.
Just my 2 cents
Regards, Markus
|