If its mineral oil based then its unlikely to contain esters. I don't think there's likely to be any esters in a mineral based Havoline.
Esters are usually included in a synthetic PCMO to help dissolve additive and aid seal swell aren't they, as well as provide Castrol with a basis for their magnetic attraction advertising.
Esters have a natural polarity that makes them adhere to metals. If you've got esters in the oil and you use AutoRx, you've got two groups of esters that are "fighting" for space on the metal parts. This will hamper the AutoRx in cleaning since it's having to "share" the metal with the esters in the oil.
I was looking at the chevron/havoline 5w20 a few months back and I did see the word ester pop up on the msds. Not sure how much though. MolaKule seems to think its a small amount. He is probably correct.
If its mineral oil based then its unlikely to contain esters. I don't think there's likely to be any esters in a mineral based Havoline.
Esters are usually included in a synthetic PCMO to help dissolve additive and aid seal swell aren't they, as well as provide Castrol with a basis for their magnetic attraction advertising.
Esters have a natural polarity that makes them adhere to metals. If you've got esters in the oil and you use AutoRx, you've got two groups of esters that are "fighting" for space on the metal parts. This will hamper the AutoRx in cleaning since it's having to "share" the metal with the esters in the oil.