Was hoping to get some advice as to the best oil for my purposes - I’ve tried the search function but there seems to be a whole load of different schools of thought…
The handbook for the S1 recommends Mobil 1 Motorsport 15w/50 or Castrol Formula RS 10w/60. Looking at various forums, a lot of people seem to recommend 5w40 or 10w50 instead though.
The car is used mostly for road driving with the occasional track day. It’s on 40k miles but has had both a bottom end and top end rebuild in the last 5000miles so is pretty fresh. Mileage will be around 10k a year in all weathers and considering I live in the North East of Scotland, the weather can get pretty nippy.
How about oil changes ?? …With Mobil 1 I change oil and filter after every 3 track days BUT am advised if I use Motul I can go all season without changing…???/
Arguement being the higher cost is more than made up by less usage…DISCUSS
[quote=MrBean]How about oil changes ?? …With Mobil 1 I change oil and filter after every 3 track days BUT am advised if I use Motul I can go all season without changing…???/
Arguement being the higher cost is more than made up by less usage…DISCUSS [/quote]
IMO, it dosn’t matter what grade/brand you use they all suffer from contamination from the combustion process. For me if it’s black it’s dirty, i change it.
Fully synthetic (or part Synthetic) oils are the price they are because the chemical make up of the oil ensures that it remains ‘stable’ and un-affected by heat cycles breaking down the molecular structure of the oil, thus reducing it’s lubrication and heat transfer qualities.
Hence the only degregation the oil suffers is the gradual accumulation of combustion by products (carbon) that in effect are microscopic is size but gradually turn the oil black. The blacker the oil is, the greater the concentration of carbon. Given this is ‘particulate’ in nature, it can cause microscopic abrasion of surfaces, ie bearings etc!
I look at the oil in my diesel and it is already going black after a few hundred miles. My boggy petrol Volvo using semi synth lasts about 6 k before the colour changes.
As a comparison, the oil in the Jet engines is burnt away about 1/2 ltr per hour… the engineers always add a few litres of oil after a typical 9 hour running cycle and the oil is always clear! In fact they never actually do an ‘oil change’ as it ‘does it itself’ with this constant topping up. It remains clean as a result!
Anyway, never mind all the above… it is quite satisfying changing the stuff every few thousand miles!
quote=pete757]
As a comparison, the oil in the[color:#FF0000] K series[/color] is burnt away about 1/2 ltr per hour… the engineers always add a few litres of oil after a typical 9 hour running cycle and the oil is always clear! In fact they never actually do an ‘oil change’ as it ‘does it itself’ with this constant topping up. It remains clean as a result!
[/quote]
Ha Ha Ha as I thought…So I really do not need to change mine Ever …only the filter.
After about 100 miles at Silverstone Stow ( and you have to try hard to do that many) IT needed about 750 ccs…so on pete’s reformula I WILL NEVER NEED TO CHANGE
Well that will save a few bob (oh sorry Pence for you youngsters)
My previous S1 never used a drop, and even at 100k miles was still yellow / translucent at oil change time.
Current one uses over 1L per 1k miles ! It’s black almost immediately (partly due to old oil left in the cooler that isn’t changed). I just change the filter now.
…With Mobil 1 I change oil and filter after every 3 track days BUT am advised if I use Motul I can go all season without changing…???/ 
