My son bought 144 bottles of Castrol 10w40 on closeout for $110. This was 2 or 3 years ago. We drive old iron and have been steadily using them up.

What felt like a wall in our garage now feels like a security blanket.

Kind of an odd viscosity unless you have classic cars or live in a hot climate

	▲	djriley 24 minutes ago \| parent \| next [-]
		He says "old iron", that could mean anything, but in my personal opinion it's probably for the best to bump up a weight once a car gets over 150k on the odometer. You get a little thicker film to compensate for wear, a bit higher viscosity to cut down on any leakage, and the same low temp performance. I would not play around with it on anything with VVT, but it's a pretty common "hack" for pre-2010'ish motors and probably even a good idea.
	▲	WarOnPrivacy 39 minutes ago \| parent \| prev [-]
		Florida. 89 Dodge p/u, 92 Buick, 96 Toyota and my son daily drives a 63 Dart. We have a 61 Sunliner I drive when the weather cools down.