This is a family members tractor that does not get serviced regularly. I am working from home because of the Covid, and am servicing many of my family's mowers and cars with my extra time. I usually run a 10w30 hdeo oil on my personal OPE, but had a jug of the Mobil 0w40 and went with that on this air-cooled tractor. It mows 5 acres about once a week here in Illinois where 70-90Â° is pretty normal for mowing season. Was the 0w40 a good choice, or would I have been better off with a 10w30 or 15w40 HDEO like Rotella or Delo?