I switched to motul 5w40 8100 excess,,car seems to likeit, no problems here.

 

5w40, the breakfast of champions (our cars)

 

Check out Joe Gibbs Racing DT-40. A high zinc oil designed for our cars.

 

Basically diesel 5W40 has a better additive package then normal car oil already.
But some are against high zinc count because of long term use Might cause cat failure..

 

I've been using Castrol 5w-40 for about 4 years now on my 996 C4S, On my 996 tt I ran castrol 5w-50 all summer for track season, doesn't get driven in the winter. 40 will break down to a 30 quickly in hot temps that tracking does. Which is why I go with the 50. Doing 12k km between oil changes or yearly which ever comes first.

 

..agreed..

 

Actually the high zinc content coupled with the phosphate (ZDDP) while risky to converters in that the zinc and the phosphate can sour the converters (form a coating that seals the exhaust gases from the catalytic metals), is also risky to the cam lobes. Too high levels of ZDDP can result in spalling at the cam lobes.

 

Used Mobil 1 5w-50 (AFAIK Castrol 5w-50 is not an approved oil) in my 03 Turbo and I couldn't tell the difference not even at the oil pressure gage between 5w-50 and 0w-40. I can't say what the oils do when used in track conditions but on the street its a coin toss.

 

To learn more about motor oil, its properties and classification,
I suggest bobistheoilguy.com, for example see
http://www.bobistheoilguy.com/whats-in-your-motor-oil/

 

what would be the approved oils for a generally cold country like Scotland?

 

Mobil 0W-40 works fine in cold climates.

 

And some highland malt in the tank to help the fuel combust better

 

Used the 20/60 for years; IMHO best oil on the planet. However the engine still "rattles". Switched to Rotella T6 syn and engine is presently quiet. If the rattles return, I will go back to the Motul.

 

I switched to T6 and she lost that Volkswagen rattle and hasn't returned

 

oil threads are great and this one's old school. for fun, there's a 12 page list of approved oils for our cars at the beginning of this thread in case it was missed. take your pick lol. it's comforting somehow to know that among the 50 or so choices of approved oils i know it's ok to use duckhams 0-40 or even pentosin's in a pinch if that's all i can ever find. as for me, i happily use a 60/40 mix of 0-40 and 5-40 M1 and it just purrs. i've only heard of that "rattle", but not heard it at 111k miles

but there's been a screech or two once at startup at 108+ degrees so that must've been before i added the 5-40