Oil recommendations

[cycleguy55]

Much, arguably too much, has been written about the need for ZDDP in motor oil for older engines - particularly those with flat tappets. I ran across an article (http://www.allpar.com/old/oils.php) that, while published in 2006, makes the case that newer oils (e.g. API grades SM & SN) are suitable for older engines as well, with the caveat that newly rebuilt engines probably need additives for the break-in period in order have the benefits provided by ZDDP.

Another option pointed out in the article is the use of motor oil designated API CJ-4, designed for diesel engines. I have read elsewhere that oil for diesel engines also has higher ZDDP than oil designated for gasoline engines - though that may no longer be true.

Interestingly, I found an old stash of Quaker State 5W30 and 10W30 in my garage labelled API SH, SJ - so that's the older stuff with higher levels of ZDDP. I guess it just sat there and gathered dust after I switched our daily drivers to synthetic, but I've got a use for it now.