According to Rotella, you can mix the two no problem.Hi all,
I changed my oil yesterday and added 3 qts of semi synthetic 10w40 and 0.1 qts of full synthetic. Is this a big issue, to mix oils?
Interesting ... they say:According to Rotella, you can mix the two no problem.
See the second last paragraph on the attached link;
ROTELLA NEWS: Will I Harm My Engine By Mixing Synthetic Oil and Mineral Oil?
Yet I found that my '08, which almost never consumed any oil for 30k miles while running almost exclusively with Bardahl Premium dino, suddenly consumed 500ml in 3000 miles after I switched to Mobil 1 4T. Go figure.There was a time, years ago, when switching between synthetic oils and mineral oils was not recommended if you had used one product or the other for a long period of time.
Some operators experienced problems with seal leakage and high oil consumption but changes in additive chemistry and seal material have taken care of those issues.