Assuming I am using high quality oils (Castrol Edge EP, PPHM, or full syn MaxLife for the Caddy DTS / Castrol Magnatec Syn, PP, or PUP for the Mazda) and filters (Napa Gold, Platinum, or Fram Ultra), is there any real danger of exceeding a 1 year OCI (max would be 18 months) if I am under 10K miles between changes? Neither cars are under warranty, and I have been changing the Mazda at 7K miles and the Cadillac once per year (which equaled about 8K miles and still about 25% on the OLM). I'm thinking I could stretch the Mazda out to 1 year or 8K miles (whichever comes first) and the DTS to 10K miles or 18 months without any real concerns. Neither cars burn oil, but the Cadillac does have a minor version of "the Northstar leak", which means it leaks a little while hot/warm, but none at ambient temperatures.
The Mazda takes 5.5qts and the Cadillac 7.5qts as an FYI.
I do not currently plan on getting UOAs on either car, but I am open to the idea. I appreciate your comments/thoughts. Thank you.
The Mazda takes 5.5qts and the Cadillac 7.5qts as an FYI.
I do not currently plan on getting UOAs on either car, but I am open to the idea. I appreciate your comments/thoughts. Thank you.
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