Oil for twin turbo USA made engine

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Please accept my apologizes if this has been replied to before: What engine oil type and grade is generally recommended for a twin turbo applications these days? Engine is above 600 hp and is a 6 liter v8 aluminum block etc. Should I go with mineral oil or synthetic? I am afraid of switching from mineral to synthetic and then see a lot of leaks. What grade is recommended when driving in hot climate? Any help and inputs welcomed. Thanks!
 
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What car / engine exactly? For any turbo I would only use synthetic. Being that its such a powerful engine with twin turbo's I would probably use Mobil 1 0w40.
 
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M1 0w40, Castrol 0w40 or Pennzoil Ultra 5w40 would all be good choices. Seeing how you're from Euroland, what choices do you have available?
 
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Any synthetic 0w40, 5w40 or 10w40 should cover the heat. Do you have an oil pressure or temperature gauge? You may be able to safely run a 30 grade like a 5w30 synthetic if you have the gauges to verify pressure at high temperatures and load.
 

jllgd

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It's a Rodeck aluminum race engine. What about the Castrol Edge TWS 10w-60? Imagine engine is to be run in high ambient temp areas. I see some discussions that concludes that the ambient temp does not matter. Not sure if I fully agree to that but any suggestions are appreciated.
 
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Originally Posted By: jllgd
I see some discussions that concludes that the ambient temp does not matter.
It can, but only you can answer that question in your case. Obviously, ambient matters most for startup. Additionally, if your vehicle's oil temperature is significantly hotter when the ambient is hotter, then that's something for which to account. If it stays within a few degrees, regardless of -20 C or +20 C, then one may not have to bump up a grade when it's warmer.
 
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If it's a typical street rod it mostly cruises easy, with some occasional bursts of full power. That is EASY, and thus use thinner oil. M1 )w-40 wins here because it is easy to get, well priced, and exceptionally stout. It's a very light 40w, but very robust at high temps. If you track that thing then all bets are off and you want something thicker. I'm in the camp that agrees you must have both oil pressure and temp gauge readings to really be sure...
 
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Originally Posted By: jllgd
It's a Rodeck aluminum race engine. What about the Castrol Edge TWS 10w-60? Imagine engine is to be run in high ambient temp areas. I see some discussions that concludes that the ambient temp does not matter. Not sure if I fully agree to that but any suggestions are appreciated.
A 6.0L V8 with twin turbo's is not very highly stressed at 600HP. GM's 6.2L LS9 supercharged engine is rated at 638HP and specifies 30-weight oil. There is no need to go for insane 60-weight oils if oil temperatures are less than 150C and steady oil pressure is maintained during extreme accelerations. A good quality 40-weight synthetic is all that is needed.
 

jllgd

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Originally Posted By: SteveSRT8
If it's a typical street rod it mostly cruises easy, with some occasional bursts of full power. That is EASY, and thus use thinner oil. M1 )w-40 wins here because it is easy to get, well priced, and exceptionally stout. It's a very light 40w, but very robust at high temps. If you track that thing then all bets are off and you want something thicker. I'm in the camp that agrees you must have both oil pressure and temp gauge readings to really be sure...
It might occasionally be used for open road racing. Is the Mobil1 0w-40 still recommended? Or will it be preferred to use a heavier grade then, like the Castrol TWS Edge 10w-60? And bottom line is that it MUST be synthetic? Because of the twin turbo application?
 
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Originally Posted By: jllgd
And bottom line is that it MUST be synthetic? Because of the twin turbo application?
If you have a post-shutdown oil pressure maintenance pump and an in-line oil cooler before the turbos, you can pass on the synthetic. The problem you're trying to avoid is stagnant oil cooking ("coking") on the turbo bearings. Always letting the turbos spin down before shutting off the engine also helps. Even if I had all those things I'd still run synthetic, because of the cost of turbos or engine rebuild versus the price differential on the oil.
 
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I would strongly recommend synthetic oil for a twin turbo engine. It's all I use for my 4 banger turbo motor.
 

jllgd

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Originally Posted By: HangFire
Originally Posted By: jllgd
And bottom line is that it MUST be synthetic? Because of the twin turbo application?
If you have a post-shutdown oil pressure maintenance pump and an in-line oil cooler before the turbos, you can pass on the synthetic. The problem you're trying to avoid is stagnant oil cooking ("coking") on the turbo bearings. Always letting the turbos spin down before shutting off the engine also helps. Even if I had all those things I'd still run synthetic, because of the cost of turbos or engine rebuild versus the price differential on the oil.
I am not concerned about the cost of the oil. Only trying to get the best oil for the engine. Nobody is commenting on my Castrol suggestion. Is that oil not good for turbos? To high grade when warm?
 
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I wouldn't be excited about using 10w60 in a turbocharged engine. Oils that have that wide viscosity spread contain a lot of VII polymer. It is the VII polymer that cokes when exposed to the high temperatures that turbo bearings are subjected to on a hot shutdown heat soak. Another thing for me that works against 50 and 60 weight oils in high performance applications is the high viscosity that slows oil drainage from the top of the engine back to the pan. If the oil can't drain to the pan at the same rate that the pump is pulling from the pan, the result is oil starvation and goodbye bearings.
 
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Stick with full synthetic. Oil temps and pressure info needed. Sump size needed. Oil pump info? cam type? vehicle usage? Nothing wrong with the synth 50 or 60 grades. But, you might only require a stout 5w30. Goldilocks' 0w40 and 5w40 are a safe bet until more info is provided.
 
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I don't think you would be well served by a 10w60. Some users have been using M1 0w40 in engines originally spec'd for 10w60 with good results. I think your choices should be narrowed down to some sort of 30 or 40 grade depending on oil temps/pressure.
 
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I used to use M1 15w50 for track days in Atlanta with a high hp turbo car. I got great oil pressure and temps with it. That was high stress and high ambient temps. That being said, the M1 0W40 has done me well in the past as well for the street. I never tracked that.
 

jllgd

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Originally Posted By: A_Harman
I wouldn't be excited about using 10w60 in a turbocharged engine. Oils that have that wide viscosity spread contain a lot of VII polymer. It is the VII polymer that cokes when exposed to the high temperatures that turbo bearings are subjected to on a hot shutdown heat soak. Another thing for me that works against 50 and 60 weight oils in high performance applications is the high viscosity that slows oil drainage from the top of the engine back to the pan. If the oil can't drain to the pan at the same rate that the pump is pulling from the pan, the result is oil starvation and goodbye bearings.
This is great info. So not more than a 40 grade oil, since it's a turbo engine. I am keen to try the Mobil1 0w-40, as I am a Mobil1 fan for many years. Does there only exist one type of this specific Mobil oil? Does it have a part number or similar I should look for?
 

jllgd

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So, engine is originally a dry sump type race engine. That will probably have influence on the sump drain back issue? And the original oil spec for engine was listed as 20w50, but back then it was none synthetic. Are we still at the 0w-40 Mobil 1? Or perhaps Mobil1 15w-50?
 
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