Which Oil ? Advice Please !

[rawstrona]

I have a std 98 chim 4.0 28k miles (recently purchased), which requires a yearly 6k service, its a weekend car only so no daily driving, i have booked it in to a reputable indie who has a number of oil options. Which Oil should i use ? some threads say mobil 1 0w 40 is sometimes too thin for cars not used daily, some say use the thicker mobil 1 motorsport 10w/40 - what about shell helix semi synthetic 15w/40 ???. With the car being stood during the week, will thinner oils leave the top end abit dry on start up ??

[rawstrona]

Thanks all for your input.

It looks like Silkolene Pro S 10w/50 ester based fully synthetic then.

Whats the difference between Pro R and Pro S ???

AL