# more power again, so is it time to change oil wight



## mk3dream (Oct 12, 2008)

im no smarta$$ when it comes to a few things and oils and lubs are something someone esle got paid alot of money to figure out so i like to stay within oem spec.... but as the car slowly becomeing less oem should i start to consider a difrent wight in oil.

so motor specfics 1.8t 
3"dp 2.5 exhuasut
ko3s 
tip
all deleats done 
revo stg 1+ - soon to be a unitronic stg2

know id normally use 5w40 but the shop im using for this says in there vrts and more performance oriented cars there using 10w60 - would this be over kill. 

the car is only summer driven so im not to worryed about the change in 5deg for cold crank


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## Apexxx (Nov 10, 2011)

Summer-driven does matter. Obviously, you know cold flow to a turbo is important.

So, does power levels directly relate to oil visc needs? Yes and no. On the extreme end, yes 350hp in mods will likely stress components. 250hp, not really. The key is the actual oil temp itself. If the oil stays at or below +100c, it'll have sufficient visc. Anything thicker than 10cSt 30 weight is meant to compensate in advance for elevated oil temps.

10w-60 is a poor choice unless the oil will run out at crazy excessive temps, basically a band-aid for insufficient cooling. It really will bog the engine down. Lightly modded turbos routinely run light 30 weight with low wear rates, reflected in used oil lab analysis. I ran Edge 5w-30 in my APT 2.0 TSI 6M and wear was very low. 

In most cases, 5w-40 is overkill, but it is the classic visc for Euro cars. The extra visc allows for extended high-speed operation, Autobahn style, and mountain driving. Likely, that's as thick of an oil as you will ever need. Pull a UOA lab test and compare the wear rates, my bet it's lower on the thinner oils. 20w-50 is even antiquated. 10w-60 will simply shear down a lot anyway.

Shop mechanics typically know squat about oil and have no data to back themselves up. 

ie: At +90c, why would you need a 30cSt 60 weight oil when 10-12cSt is more then adequate?


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## mk3dream (Oct 12, 2008)

:thumbup: that there is a fantastic respons 
10w 60 then would be major over kill at 100 deg it would be to thin correct and wear prematurely ?

like i said im no oil guru but i do like to know my stuff, if i sound like a dum ass it cause im trying to understand something i have not been educated on :laugh:


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## Apexxx (Nov 10, 2011)

What I'm saying is the 10w-60 will be 3x thicker than needed, bogging down the engine and reducing FLOW. During warm-up the oil stays really thick and causing premature wear, overly thick oil is worse in that regard. 

Heavy oil may in fact be fine for the track for 2 reasons. One is the extended high speed operation that drives up oil temps (thinning the oil, see the graph), the other is the fact the race engine isn't subject to multiple cold-starts and warm-ups a day, where thinner oil is the best choice. It's like sucking a milkshake thru a straw.

See, the engine only needs about 8-9cSt of visc at any temp, but the oil starts out cold at 1000s of cSt, only thinning down as the standard +100c operating temp is reached. 

So, a 30 weight at 10cSt (+100c) or a 20 weight at +9cSt is fine at normal temps, drive temps up and you thin the oil too far. You can compensate for the high temps by starting with a thicker oil that can be heated further until it thins too far(see chart) also, bearing in mind the cold starts, not applicable to you.


Engines and oil take 10 miles or 15 min to warm up fully. Water temp comes up quicker by design, mostly for emissions. In winter, many cars never make full operating temp, which means they chug around on overly thick oil and w/o reaching +100c, it never gets hot enough to boil off contaminates, water and excess fuel.

In Canada, I'd grab some Esso XD-3 0w-40. That or stick w/a 5w-40 and you are good.


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## gmikel (Nov 10, 2010)

*apexxx*

=bullshirt


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## mk3dream (Oct 12, 2008)

i see , ill just stick with the vw speck  its no race car. 
thanks for the great write up


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## JohnStamos (Feb 3, 2010)

*FV-QR*

Find a new shop as well. I wouldn't trust them after that "advice"


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