engine oil question

my 1.8 jap mx5 is due a service soon and i was wondering what oil i should use as its drivn prety hard on a daily bases and does a few track days too. i was thinking millers 5w 40 motorsport oil?
A little corner set aside for MX-5 enthusiasts
http://www.mx5ireland.com/forum/
93 Mk1 wrote:I always use 10w 40 semi synthetic in my MX5's. I think 5 weight is a tad too light for these engines.
Steve wrote:10w40 Magnatec works well.