Ive done this on all my junk. I like the synthetic because I run longer oil change intervals. 6K vs. 3K. All are 165K or higher mileage. They do not leak or burn any oil. Ive been using 5-40w Rotella T-6 on sale at 20 per gallon but would try others if on sale. Ive done this to my kids cars with the same results. I do lube them at 3k for a little peace of mind.
Its like a fart in a windstorm
It smells good but thats about it
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