I am just going to buy a gallon of oil for an oil and filter change and thought i'd change the spark plugs whilst I was at it.
Can anyone recommend a specific brand or type of oil I should go for? Probably be a Halfords trip in EK to be honest

Similarly for the spark plugs?
It's a 1999 T MPi. The mileage is at 51,000.
I've read on another forum that Mini engines are not designed for synthetic oil and mineral oil is to be used. I'm not sure what oil was put in by the garage when THEY last done the service, but I have topped the oil up with some oil I was given and it's 10w-40w. Not certain if it's synthetic or mineral now.
What is better for me to buy? Is synthetic oil safe on Classic Minis?
Cheers,
Picco