Does Motorcraft still offer a blend? I recall folks being satisfied and happy with it.
As someone said, I think most conventionals are going away to meet API SP ratings, but if the words on the label make you feel better here are a few options:
Amazon Basics $21.43
STP 6 gallon - $80 (3.33/qt)
Traveller/Tractor Supply - $19
Providence/Rural King - $15
Providence Automotive motor oils are formulated with highly refined base oils combined with a carefully selected additive package to provide maximum protection against wear, rust, corrosion, oxidative thickening, acid formation, sludge and varnish depositwww.ruralking.com
Yeah, with an old car, there's no way I'd want to have to pull the transmission to fix a leak that sludge was "repairing". New oil chemistries (say, of a semi-synthetic versus a non synthetic??) can (I believe) act as a solvent for said sludge.If you use synthetic oil and then it starts leaking, then fix the leak. Leak was already there, it was just being plugged with sludge.