Which oil and plugs to use?

I need to do a service on my 340R (standard 177 engine) and wondered what plugs and oil people are using? The recommended plugs are Champion RC6YCC which seem to be getting harder to source. I have been recommended to use RC8PYPB4 as an alternative, but this appears to be the standard K series Elise plug and I can’t see why Lotus would have recommended the RC6YCC for VHPD variants if the RC8s were as good in this application?

The recommended Castrol RS oil is also becoming hard to source and I’m wondering whether to switch to the Castrol Edge equivalent or one of the “proper” synthetics.



No idea on plugs. But

A good Synthetic is the usual recommended choice.

Castol Edge is claimed to be a long life synthentic, probably suitable.

I use Redline.

Silkolene, Millers, Comma are the usual choices.

Bell&Colvill use Shell Helix Ultra and I’ve continued this and not had any real complaints over 5 years.

It does go through nearly a litre on a hard trackday but I guess that means it’s getting to all the right places (and a bit beyond the rings).

I seem to recall posts about the thicker Mobil 1 not loosing as much.

When I service the car in Q4 I’m going to switch to something hopefully just as good/better but a bit cheaper and was going to enquire with oilmansi (PM or do a search).


Castrol edge is the new name for the whole range of oils, but ‘Castrol Edge Sport’ in it’s various guises is the direct replacement for the old RS range.

Millers full synthetic 10-50 competition. Excellent oil and around the cheapest full synthetic around.

use Rc6Ycc plugs

I wouldn’t recommend using Champion heat grade 8 plugs in an S1 exige