First time to service "new" car before getting many miles on as warm weather approaches, so please can I have advice on preferred oil viscosity (hopefully 15:40 'cause that's what I bought)and tips on emptying and re-fill process (filter change first or afterwards?) to avoid any risk of no oil pressure after change
Many thanks - John

Hi John, I have been investigating the very same issue and stumbled across www.gomog.com albeit an American site, it effectively contains an on line workshop manual for the +8 along with other models. It covers in quite detail the procedure for changing the oil and priming the system. Hope it helps. Steve

Thanks Steve; I'm going to use Castrol magnated 15w40, it's semi-synthetic but spec suggests it should be ideal
yes, i'm a fan of GoMog already, it was brilliant for my much older Plus-4
Let me know how you get on with your oil change and any tips you can pass on will be greatly appreciated
kind regards
John

15/40 Magnatec should be fine. I used that 'later on' in my 3.5V8 (in an MGB)but for many years used Valvoline 20/50. I never had 'no pressure' after an oil change, but always filled the new filter before fitting. It reduces the time delay before pressure builds up, and this is relevant for all engines with a hung filter.

Hi,
On a Plus 8, you have to be very careful because the oil pump can be deactivated if it becomes empty (even partially), it is a very well known problem on the Rover V8/Buick 215.
I always fill up the new filter with fresh oil, then remove old filter, and immediately screw the new one. With this method didn't have any problem. I use Motul 300V Competition 15w50, one of the best full synthetic oil. I had it analysed by a private laboratory and found that it had the corect level of ZDDP for these engines.
BR
Daniel.