LGN's come from factory with following tyres in 185/65 R 15 dimension:
1. Montana M801 (Kormoran K801) - not recommended
2. Michelin E3A (T speed index) - recommended
3. Continental EcoContact3 - recommended
As for spark plugs....ask in Renault serivce, I believe that original Renault spark plugs are the best ofr your engine.
Factory liquids.....I have no idea
I had only oil changed and they use Elf Excellium LDX (i think so)......