Re: Engine Oil
There is so much out there about this type of question- and honestly, there are as many people that will say one thing and the same number of people that will counteract the advice with other opinions.
I do agree, it is a matter of knowing your engine, its age, its former abuse if possible, and what your experience is.
My 66 LTD has the original 352 with 70,000 miles on it. I tried at first the recommened 10w-30. I found the car burned oil alot more at that weight.
I went to my go to, that I have used now for years, on both my 66 Mustang and 66 LTD- Shell Rotella 15W-40. I know, diesel oil, but with the tiny bit of extra zinc it has, and a small amount of Lucas ZDDP additive, I have the right ration of zinc in the oil. Never had any issue, both cars don't burn oil at all and I drive each one about 3000 miles per year, gently.