Should have gone to Cressing matelol
edit: Why were you in Chelmsford when your location says leicestershire?!? lol
Renault quote that 10-40 is fine so long as outside temsp don't drop below -20 so there fine its better to use 5-40 thoughthey "should" use elf 5W40 excellium
but 95% of dealers use 10W40 as they make more money out of the service/have no idea what oil they "should" use
we use 5W40 Elf excellium on all of our services for Renault sports
I will admit that i'd tend to steer clear of say Halfords own brand if i have to buy oil, but I use Shell Helix Ultra in mine (as i get it for free from work,where we put it in the Loti, Subaru's and Saabs) and have never had any reason to think "oh no, its the wrong stuff!"
that would make it mineral oil (god forbid)![]()
Its mainly psychological when it comes down to what to use both oil and fuel wise, although with fuel there are obvious gains/losses that come from using different brands.