I know I’m poking a hornets nest with a stick:
Mix it half and half with some 0W-20 and call it a day.
I had oil changed today and realized that I have a 15w-40 as well and I was wondering.
The mechanic complemented the condition of my car - I am naturally very particular and I don’t let them to overfill fluids either - for that I had been back to double check. I briefly went to Kendall semi syn at Firestone - it is not as good as Mobil full syn in the winter here (northern ca) considering the car is also used for dropping the kids at school. So I am using full syn for the winter months at least as I had better results (within my observations).
I will be donating the shell 15w-40
The excess ZDDP won’t hurt the cat unless you’re burning oil. It should be dual-rated S(x)/C(x) oil…good for spark and compression engines. I’d thin it out like it was already said and go for it.
Dont think it works that way,I remember a guy who was mixing two different types of oil,trying to make some 50W for a pump drive,needless to say it didnt work,there was more chemistry,then arithmetic invovled.
I am in Northern California - I never needs to add oil after an oil change - it doesn't burn oil.
What’s your logic behind changing? Makes no sense to me.
The Blackstone newsletter some time ago involved the Blackstone guy buying old oil, I think as old as the 50’s, just to see if it was still good. He even ran some of it in a personal car. He said it was still good. Of course, being Blackstone, he printed the test results.
Here in Mexico, one of the really strange things is people think you must use 20W-50 or you will wreck your motor. So, that is what the stores stock. Once, Autozone in Tehuacan didn’t even have anything else.
Once, I was looking for a quart of 10W-30 and went into a local oil store. The punk moron there snarled at me, "It will destroy your motor."w
I had a businessman, owns x-ray machines and sets up doctors as x-ray operations, tell me that motors produced for sale in Mexico are not good motors. That all the good motors are shipped to the US, and the rejects are used in Mexican cars. Big businesses simply do not do business that way. It costs less to make identical numbers of any item to the same quality. But, he believes it.
In reality, they are probably good motors until they get driven a distance with 20W-50.
I shudder to think what is going to happen to a new 0W-20 motor with 20W-50 oil.
I’m assuming the owner’s manual for your van says to use 5w30 or 10w30
If the auto parts stores stock mostly/only 20w50, is it also the case that repair facilities only stock 20w50?
Where do you get 5w30 or 10w30, or whatever your van is SUPPOSED to get?
Those gallon jugs of 15W-40 oil with Toyota labels used at the Lexus dealership will always remain in my mind as a great question mark to the questionable threat of catastrophic engine damage when heavier oils are used in hotter climates.