My brother is driving his 03' Mustang 3.8 conv. from NYC to Florida where he will leave it to use
for his visits there. He is retired and plans to spend about half his time in NY and half in Fla. The car calls for 5w20. Is this motor like the Ford modular V8 which seems to like the thinner oil or would he be better off with Mobil 1 5 or 10w30 year round in Florida. Also would 1 year /7500 mile OCI be okay with M1. Thanks