S2 Engine Oil

[alg]

After reading this thread from top to bottom, I'm even more confused

I just Mihnea's judgement about running the ABY with 10w-60 BUT I want to be sure that switching from 5w-40 to 10w-60 will not damage my engine in ANY way as it runs fabulously on 5w-40 ( though I have to admit that I can't really compare ).

Anyone got a definitive answer on this one ?

A good quality synthetic oil within recommended spec will not damage the engine.
Infrequent changes, poor quality oil and failure to check levels will.
For what its worth I have usually used 5-40 mobil 1 then synta gold (which went from 10 to 5w last year) in S2 then RS2 with 5K changes and no real issues.
However the RS2 was using a bit of oil so I switched to Mobil 1 15-50w on the last change with no drop in levels at all.
What do I think....well as things get older a 'slightly thicker' oil makes sense if find the car is using oil otherwise just stick with your favourite.
I do not believe their is a definative answer for all cars

[valjo]

i use castrol rs 10/60 on my aby. i am very satisfacted with it, idle presure is about 1.5-2 bars. i have used esso ultron 5/40 and sometimes idle oil pressures droped bellow 1 bar (very hot day, and hot engine). i had some others problems with esso oil, my cam flowers
used to be noisy from time to time , but with castrol rs those problems gone.
so i prefer rs oil....

[1975DCS]

I asked several S2 tuners what they recommend a guess what: Some say 10w60 (with no technical explination) but 2 very renown Scandinavian tuners replied to use 10w50 as a maximum because of the hydraulic lifters. I like answers like this: funed with a reason! Personally I think the 10w60 maybe be good on race specd engine, but for roadgoing vehicles...

I have had powerful turbo cars (Cossie and C20LET) before and sticked to 5 or 10w50. The C20LET had a rebuilt and it was Castrol RS 10w60 sludge everywhere. The guys who have rebuild the C20LET (Cosworth specialists) warned me for the sludge problem with Castrol RS 10w60 on higher temperatures.

I have been reading a lot of forums and technical magazines the last decades and also asked a lot of questions to people out of the "turbo" tuning and Rallycross scene. I have also have contact with lubrication specialists. And with this in mind I've learned a lot:

- 10 or 15w40 semi synthetics are much better than anyone think they are
- 10w60 is too thick for road applications
- 0w oils are way too thin, also for engines "designed" for this, VW now realizes this!
- People think that higher oilpressure also mean a better oil
- People use thicker oil, because of high temps, while they should use a better cooler
- People use some oil because it is used in whatever application they like, so automaticly think it is good for there's too

I would also like to point out there is a Dutch test (with Laboratorium help of Kendall Oils) refering to Oil weights on Subaru Impreza GT's... And guess what: 10w40 (both mineral and semi-synthetics!) as Subaru recommends was 2nd best. Only 5w50 was better and declared as winner. 0w40 and 10w60 were very clear worse of the test!

When I asked Amsoil about my C20LET engine they said 10w60 was way overdone, and they said 5 or 10w40 for normal and 5w50 for extreme road going use was the way to go...