Oil - What weight do you use? (Please forgive me for asking...)

[projectsmorol]

Driven racing oil DT40. The type of oil you choose should come down to how, where and when the vehicle is driven.
How: heavy foot, track days
Where: tons of city driving vs mostly highway etc.
When: Is it primarily a summer car? or does it see four seasons? Are you willing to change the oil to match the driving conditions?

This is why most major branded oils cover such a wide range of the above. They are your best all around choice. Look at you owners
manual. They will recommend proper oils. They usually recommend a brand but choose something within your budget. Don't mix oils of different brands, viscosity etc. Try to use the same oil for longer periods. If your vehicle uses a little oil...when you do a change make sure to have a quart or two extra, 1 for trunk 1 for shop or garage as a back up.

[callahanoffroad]

I'm not sure the controversy over what constitutes a "full synthetic" motor oil matters. Seems like a semantic distinction

It’s like filling up at Sunoco, the official gas of NASCAR, to get that extra 15 HP

Pretty much any oil over Crisco, with a good interval, will make a Volvo engine outlive the car.

Which is really saying something bc I've yet to see a rusty 850 body that has been even lightly maintained.