Just use the recommended 5w40 by renault, then you wont need to worry about opiinions. Just get a good quality oil, not cheap tescos stuff. I also used the halford 5/40w Fully Synthetic. Oilman from opieoils says the halfords stuff isnt as good as a genuine synthetic.....but to be fair ive driven for many years and always used halfords oils and never ever had any engine issues as a result of wear and tear of internal components.
If you are going to use the "cheaper" brands like motul/halfords/etc then do the change once a year instead of every two years.