Flat 6 engine oil

pennerdodge Posted 2017-05-08 7:29 AM (#539677) Subject: Flat 6 engine oil Regular Posts: 82 Location: Eastern Manitoba What grade of engine oil is best for my somewhat tired 57 flat 6 dodge. Should i be putting straight 30 or a multigrade oil like 10w30 or 15w40? mstrug Posted 2017-05-08 5:00 PM (#539706 - in reply to #539677) Subject: Re: Flat 6 engine oil Expert 5K+ Posts: 6502 Location: Newark, Texas (Fort Worth) 10-40 Rotella or Brad-Penn. They have the zinc for less wear. pennerdodge Posted 2017-05-09 8:13 AM (#539753 - in reply to #539706) Subject: Re: Flat 6 engine oil Regular Posts: 82 Location: Eastern Manitoba Thanks