I found this on the web....
"I put in some serious time reading up on oils for 1.8t, this is what I found and how I'd rank them.
User account number (aid): 27563
Posted by Audi Junkie on 2002-11-03 21:03:17
I've been putting in overtime at theoildrop.com From what I can gather, a chipped 1.8t is very hard on oil. Synthetic is a must. Synthetic means several things though. Group III is "cheaper" hydro-cracked molecules (big molecules made smaller) and has decent properties which can be enhanced with good additive packages to perform even better than the true synth that everybody whines about.(small molecules made bigger) That kind of synth is Group IV (PAO) or Group V (Esters) In your engine, there is not really a ton of difference except: wear, friction, seal swelling/shrinking and deposits. Wear and friction can be minimized with additives like moly, phosphorus, zddp, etc. These are *important* to handle the Extreme Pressure of turbo & diesel engine parts. EP additives take over and form a barrier when the oil film is broken down(squeezed) and prevents metal contact and scoring. Otc oils have minimal amounts of these compounds. Seal swelling is addressed in advanced formula synthetic Group IV and V oils by blending PAO and esters, to balance the fact one swells them and one shrinks them! As far as deposits, it is a critical consideration in 1.8t engines. When you shutdown, a portion of oil in the turbo is cooked and this is where vastly different results occur. A PAO (polyalphaolefin)sp? Group IV oil will leave a hard (plastic?) deposit where a ester based Group V oil *will* evaporate cleanly without a deposit. (possibly, Group III does too) This is where reading and learning the whole story is important, the PAO has a higher flashpoint, but leaves the harmfull deposit when it does burn off. Looking at the specs alone is misleading. As far as I can tell, a Group III oil with good additives can therefore be better in your engine then the eliteist Group IV! It tests better, works better but people want the built-up "true synth". Now, the big question is what are the contents of the various otc oils! Mobil 1 0w-40, GroupIV, NOT the Group III that everyone (including me) speculated Mobil 1 SuperSyn had converted to. Is it beter than a good III? No, for the one reason of the PAO deposits, additive packages may not be as good too. It is not a bad oil, but there is a bias against it at TOD.com Surprisingly, the ACEA 3/upcoming GF-4 rating is a bad thing in terms of the metallic additives that protect your engine! This is mostly because of strict Euro enviromental regulations, and the 0w weight is for fuel savings not for top engine protection!(CAFE standard mpg is based on recommeded oil grades!) So, a quality API SL Group III synth is fine, which allows more choices other than M1, like 5w-XX. BTW-Most otc synths are, regardless of what the maker says, Group III, specialty synths are IV and V as well as M1.
What you want in your chipped 1.8t is something like the Mercedes-approved synths:
(I put them in order based on my readings)
1)Kendall GT-1 FullSynth 5W-40
2)Chevron Supreme Synthetic 5W-40
3)Valvoline Synpower 5W-40
4)Havoline Synthetic 5W-40
5)Pennzoil Synthetic Euro 5W-40
6)Mobil 1 0W-40 and 15W-50
7)Quaker State Synthetic Euro 5W-40
8)Castrol Syntec 10W-40 and 5W-50
or if you drive it really hard, use a mixed-use oil like Delvac 5w-40 or Rotella T 5w-40 with plenty of EP additives. Testing seems to be the key to finding out what is in an oil and what it does over time. 2 tests, before and after. It is a bit confusing but people at theoildrop.com can help interpret test results. I am, by far, no
"I put in some serious time reading up on oils for 1.8t, this is what I found and how I'd rank them.
User account number (aid): 27563
Posted by Audi Junkie on 2002-11-03 21:03:17
I've been putting in overtime at theoildrop.com From what I can gather, a chipped 1.8t is very hard on oil. Synthetic is a must. Synthetic means several things though. Group III is "cheaper" hydro-cracked molecules (big molecules made smaller) and has decent properties which can be enhanced with good additive packages to perform even better than the true synth that everybody whines about.(small molecules made bigger) That kind of synth is Group IV (PAO) or Group V (Esters) In your engine, there is not really a ton of difference except: wear, friction, seal swelling/shrinking and deposits. Wear and friction can be minimized with additives like moly, phosphorus, zddp, etc. These are *important* to handle the Extreme Pressure of turbo & diesel engine parts. EP additives take over and form a barrier when the oil film is broken down(squeezed) and prevents metal contact and scoring. Otc oils have minimal amounts of these compounds. Seal swelling is addressed in advanced formula synthetic Group IV and V oils by blending PAO and esters, to balance the fact one swells them and one shrinks them! As far as deposits, it is a critical consideration in 1.8t engines. When you shutdown, a portion of oil in the turbo is cooked and this is where vastly different results occur. A PAO (polyalphaolefin)sp? Group IV oil will leave a hard (plastic?) deposit where a ester based Group V oil *will* evaporate cleanly without a deposit. (possibly, Group III does too) This is where reading and learning the whole story is important, the PAO has a higher flashpoint, but leaves the harmfull deposit when it does burn off. Looking at the specs alone is misleading. As far as I can tell, a Group III oil with good additives can therefore be better in your engine then the eliteist Group IV! It tests better, works better but people want the built-up "true synth". Now, the big question is what are the contents of the various otc oils! Mobil 1 0w-40, GroupIV, NOT the Group III that everyone (including me) speculated Mobil 1 SuperSyn had converted to. Is it beter than a good III? No, for the one reason of the PAO deposits, additive packages may not be as good too. It is not a bad oil, but there is a bias against it at TOD.com Surprisingly, the ACEA 3/upcoming GF-4 rating is a bad thing in terms of the metallic additives that protect your engine! This is mostly because of strict Euro enviromental regulations, and the 0w weight is for fuel savings not for top engine protection!(CAFE standard mpg is based on recommeded oil grades!) So, a quality API SL Group III synth is fine, which allows more choices other than M1, like 5w-XX. BTW-Most otc synths are, regardless of what the maker says, Group III, specialty synths are IV and V as well as M1.
What you want in your chipped 1.8t is something like the Mercedes-approved synths:
(I put them in order based on my readings)
1)Kendall GT-1 FullSynth 5W-40
2)Chevron Supreme Synthetic 5W-40
3)Valvoline Synpower 5W-40
4)Havoline Synthetic 5W-40
5)Pennzoil Synthetic Euro 5W-40
6)Mobil 1 0W-40 and 15W-50
7)Quaker State Synthetic Euro 5W-40
8)Castrol Syntec 10W-40 and 5W-50
or if you drive it really hard, use a mixed-use oil like Delvac 5w-40 or Rotella T 5w-40 with plenty of EP additives. Testing seems to be the key to finding out what is in an oil and what it does over time. 2 tests, before and after. It is a bit confusing but people at theoildrop.com can help interpret test results. I am, by far, no
