Originally Posted By: tommygunn
At 5k there is no point in using a synthetic, but of course it won't hurt anything, and some synthetics can often be had for the price of dino and/or a rebate that makes it end up being just as cheap.
^^This
Since synthetic is often available with a deal, you may as well run it.
You could take advantage of rebate deals on both Quaker State Ultimate Durability and Pennzoil Platinum or Pennzoil Ultra by resistering you Altima for both the Pennzoil and Quaker State warranty rebates, for example.
If you have no interest in chasing deals, a 5K OCI on whatever current spec dino is on sale should also be fine.
WRT leaks, I've never seen them on engines we've run on 90% syn OCIs from new.