Is a semi enough?

[Gizmo!]

When I get my car back I'm going to show it some TLC. Change the oil and filters and suchlike.

Things is I've got a big bottle of semi synthetic from topping up my old BMW; is this enough or should I be getting a fully synth?

The MX5 isn't a highly-tuned engine but it is getting old...


What?

[garrykiller]

[Metalligator]

Firstly, that's what she said, secondly.

What do you use the car for? Daily commute? Fast road? Track days?
What temperature extremes does your car usually live in?
Also what weight is the oil?

[JonnyFive]