Quicker turbo spool up with redline 5w30 then GC

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I have been running GC in my twin turbo Audi S4 for the past 4 years. Oil did well during the street and track use as confirmed by my UOA results. This weekend I replaced GC with Redline 5w-30 to get a bit more safety cushion with high oil temperatures car sees during the track duty (275-280F range). Car runs smooth(er) and I also noticed faster turbo spool up then I ever had with GC Here are their respective specs: GC RL vis @ 100C 12.1 10.6 HTHS 3.6 3.8 I guess Redline just has lower coefficient of friction?
 
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 Originally Posted By: zoomzoom
I have been running GC in my twin turbo Audi S4 for the past 4 years. Oil did well during the street and track use as confirmed by my UOA results. This weekend I replaced GC with Redline 5w-30 to get a bit more safety cushion with high oil temperatures car sees during the track duty (275-280F range). Car runs smooth(er) and I also noticed faster turbo spool up then I ever had with GC Here are their respective specs: GC RL vis @ 100C 12.1 10.6 HTHS 3.6 3.8 I guess Redline just has lower coefficient of friction?
I've noticed the same in my turbo car when switching between different viscosities. More so with the journal bearing turbos. Really can't tell a difference with the dual ball bearing units.
 
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Redline claims to have the lowest friction of all motor oils- maybe all that moly combined with the ester basestocks?
 
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I've noticed the same thing in any car or truck whenever I go to a lower viscosity oil. You just have to decide what your priorities are for the vehicle and make a sound decision based on what's important to you.
 
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Thinner oil is the most logical reason. Less friction would imply that there was metal to metal contact that was being corrected.
 
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 Originally Posted By: qship1996
Redline claims to have the lowest friction of all motor oils- maybe all that moly combined with the ester basestocks?
I'd say this is about 90% the reason; the other part is the lower operating viscosity of the Redline...12.1 vs. 10.6.
 

zoomzoom

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hm turbos are journal bearing design so lower viscosity of Redline and lower friction would make them spin easier, but I was of the impression that GC is also low coefficient of friction oil.
 
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Most likely a viscosity reason, but RL could potentially have a lower cf. Hard to really say. Redline does use a POE base which naturally has a lower cf than PAO, plus a lot of moly used as both a FM and AW additive.
 
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I would like to comment on the viscosity effect on a different car. When I changed from the factory fill (12.07 cst at 1100 miles) on my 08 GTI to redline 5W40 (15.1 cst) there was an immediate improvement in spool up. I drove the car the same manner as before and I actually had to learn to drive it a bit differently because it wanted to spin the tires from a stoplight. There was no change in power that I noticed but definitely more power sooner. It was quite a dramatic change even though I went to a thicker oil. Just my experience.
 
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 Originally Posted By: saaber1
I would like to comment on the viscosity effect on a different car. When I changed from the factory fill (12.07 cst at 1100 miles) on my 08 GTI to redline 5W40 (15.1 cst) there was an immediate improvement in spool up. I drove the car the same manner as before and I actually had to learn to drive it a bit differently because it wanted to spin the tires from a stoplight. There was no change in power that I noticed but definitely more power sooner. It was quite a dramatic change even though I went to a thicker oil. Just my experience.
Very interesting. Any idea why? I hear you about the change in powerband. I ran into the same thing.
 
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 Originally Posted By: BuickGN
Very interesting. Any idea why? I hear you about the change in powerband. I ran into the same thing.
I don't know but polarity, as seen in these snipets from an article via TomNJ, may explain it: "The primary structural difference between esters and PAOs is the presence of oxygen in the hydrocarbon molecules in the form of multiple ester linkages (COOR) which impart polarity to the molecules. This polarity affects the way esters behave as lubricants in the following ways: "2) Lubricity: Polarity also causes the ester molecules to be attracted to positively charged metal surfaces. As a result, the molecules tend to line up on the metal surface creating a film which requires additional energy (load) to wipe them off. The result is a stronger film which translates into higher lubricity and lower energy consumption in lubricant applications." "...In addition, polyol esters usually have more ester groups than the diesters and this added polarity further reduces volatility and enhances the lubricity characteristics while retaining all the other desirable properties inherent with diesters. " Here is the article: http://www.bobistheoilguy.com/forums/ubb...994#Post1252272
 
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Redline in our Outback (non turbo) ran the smoothest/quietest of any oil so far. Yes subjective I know but I have a very good ear (ex hi fi nut) and owned many vehicles.
 
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