Cheers guys.
The oil i've added is 5w40. Been looking at it the last few days, and until i've been driving 10mins and its warmed up, the pressure guage is maxing out completely if i go over 20mph. I wont do anything as my oil level is correct (checked after letting the engine cool for 10mins, so it must be new oil + the weather.
I'll update in a couple of hundred miles.