Hi,
I just bought a mx-5 (miata) and it needs a service, The owner manual suggests 5W30 or 10W30 (SG, SH, SJ. At this moment is has Total Quartz 9000 5W30 in it. However, the mobil site suggests 0W40(synth) or 5W40(semi synth), Castrol suggests 10W40...
It's a summer/weekend car that sits in a...