What grade number of motor oil to use on a high millage van?

I live in east Texas. About 4 days ago me and my dad did an oil change on hes chevy astro van, and we added 10w-40w, and it has over 160,000 miles. Did we add the right oil? Thanks for any advice!!What grade number of motor oil to use on a high millage van?
Synthetic oil would be the best. And also add Lucas Additive.What grade number of motor oil to use on a high millage van?
that depends on the situation. if it leaks or burns oil 1040 or even a 1030 high mileage will work well. if it does not consume oil at a high rate then stick with the 530. but an Astrovan with let me guess a 4.3 liter engine and a 4l60 transmission, i would go with the 1030. the 1040 should do well, it might drop fuel economy a little though.
I used tu hev smoke frum da truk u mine. i uses 90 wet lube. itdont smoek mo mor.


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Yes, the 10w-40w (detergent) oil is designed to stay thicker in warm/hot weather and to become slightly thin in cold weather. If the pcv valve is heavy with burnt oil residue you will want to change the oil MORE often to help remove the build up in the engine and change the pcv valve to ensure adequate breathing of the engine