Rotella t5 instead of t4 (cannot find any)?

My pick up ran conventional for 275 thousand miles or so with no leaks. I switched over to full synthetic and my oil pan, rear cover and rear main seal began to leak. Went back to dino and the leaks have slowed down but still there and they weren't before. It seems to be a high mileage deal. All the cleaners in the synthetic oils removes the gunk inside that was stopping the oil from escaping weak gaskets. Once that gunk is removed the oil can now push it's way through to the outside.

 

Run 50w like we did in old equipment. You could also run gear oil. Lol

 

Ha! Gear lube certainly crossed my mind but that drivetrain has 315k on its right now. 10w40 is as high as I want to push it.

 

Synthetic oil will dissolve some of the sludge in the motor. So if there is a bunch of sludge behind an already worn seal, it will leak. The problem is not synthetic per se, it is worn parts. Synthetic is also thinner when cold (5w40 vs 15w40), and the oil molecules are more consistent in size.... so if you have a worn engine, yes it will burn more. I personally am a fan of true synthetic oil, everything I own gets it besides the stuff that leaks or burns like crazy, because you are constantly adding new oil.

 

I buy oil by the tote. Costs me a little over $4/L. I save over $2/L buying that way rather than by the pail or jug.