5W-20 and 0W-20 - why not in turbocharged engines?

[metroplex]

If 5W-20 and 0W-20 are "so great" for Ford's OHC V8s, why aren't they spec'd for use in engines like Subaru's turbocharged 2.0 and 2.5 motors or Porsche engines? They're also OHC but they just have turbochargers.

I would think the 20 weight can't handle the heat from the turbocharger.

What do you think?

 

[pscholte]

I would not use them in a turbo without test results that show they can handle it. Having said that, I'll bet there are guys, who in 197X, put the then brand new M1 5W20 in their turbos without incident...still, it is not something I am prepared to do without seeing data.

 

[buster]

I think Redline and Mobil 1 20wt viscosities are the best built and I think they would do fine. Redline/Mobil 1 use a high amount of esters and EP/AW additives. I wouldn't use it for long drains but to gain a few HP I think it would be ok. I would obvioulsy sample the oil imediately after a track race. Redline's 5w-20 is almost a 30wt with a HT/HS of greater then >3

[ September 28, 2003, 04:48 PM: Message edited by: buster ]

 

[Quattro Pete]

quote:

---

Originally posted by metroplex:
If 5W-20 and 0W-20 are "so great" for Ford's OHC V8s, why aren't they spec'd for use in engines like Subaru's turbocharged 2.0 and 2.5 motors or Porsche engines?

---

We've seen time and time again that oils like M1 5w-30 (a rather thin 30 I might add) perform very well in the 1.8T VW/Audi engines - search for UOAs on this board. We've also seen that the M1 Xw-20 is not all that much thinner than M1 30 weight, so it's quite possible that it would work just fine in this application. But it sure would be nice to confirm this with some UOAs.

Personally, would I run a 20 weight oil in my 1.8T? Unlikely. The minimum recommended weight in my owner's manual is 0w-30, and I have no reason to go lower than this. I can afford to dish out those few more pennies at the gas pump if in fact a 20 weight does offer better fuel economy. FYI, I'm actually running M1 0w-40 in it now.

 

[Ken2]

Metro,
Good point. The extra heat in the turbocharger's bearings will thin any oil and reduce the film thickness and strength. Present xW-20 oils may be too light under that heat.


Ken

 

[TooSlick]

Metroplex,

There are 0w-20 synthetics being sold in Europe for use in turbocharged engines. One example is the "Fuchs" Titan synthetic, which is an ester based product. As a practical matter the high temp/high shear viscosities of the 0w-20/5w-20 oils are very close to some of the 0w-30 and 5w-30 oils, so the difference is more perception than reality.

For example:

XL-7500, 5w-20 - HT/HS is 2.9 Cp
Mobil 1, 0w-30 - HT/HS is 3.0 Cp
Synergyn 0w-20 - HT/HS is 2.8 Cp

If these engines work with the Mobil 1, 0w-30 or 5w-30 you could also use some of these 0w-20 and 5w-20 synthetics with no problem. I'd expect oil temps to be slightly lower with the xw-20 grades due to a reduction in "intrafluid" friction. As a result, oil pressure with the three oils shown above will be almost identical. I've been running the Synergyn 0w-20 in a 2.4L Tacoma pickup for the past six months and it works very well. About 2% better fuel efficiency than the Amsoil 10w-30 synthetic and NO oil consumption.

TS

 

[Jay]

From Mobil 1's 0w-20 product data sheet:

quote:

---

Applications
Mobil 1 0W-20 is recommended for all types of modern vehicles, especially high-performance turbo-charged 4 and 6 cylinder gasoline and diesel multi-valve fuel injected engines including those found in passenger cars, light vans and trucks where a 0W-20 or 5W-20 viscosity grade is specified.

---

Also, the Synergyn 0w-20 has a CH-4 rating and some long-haul truckers with turbo-charged diesels are using it.

 

[Dr. T]

Why don't they use 0-20 in Porsches? They're not A3...for now that is....

 

[buster]

quote:

---

XL-7500, 5w-20 - HT/HS is 2.9 Cp
Mobil 1, 0w-30 - HT/HS is 3.0 Cp
Synergyn 0w-20 - HT/HS is 2.8 Cp

---

Depends which 20wt oil you are talking about. Redline and Mobil 1 use a higher percentage of Esters and more EP/AW additives then Amsoils 20wt. I would not even pay attention to the HT/HS of these oils. We've seen that Mobil 1 10w-30 has a 3.2 HT/HS and is as stable as you can find and that Mobil 1 0w-40 is at 3.6 and is not. So I'd go with a 20wt that is made with a good amount of additives over a basic Amsoil 5w-20 and feel safer. It's not always the benchmark tests but the chemistry used.

[ September 29, 2003, 05:22 PM: Message edited by: buster ]

 

[pscholte]

quote:

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Originally posted by Jay:
From Mobil 1's 0w-20 product data sheet:

Applications
Mobil 1 0W-20 is recommended for all types of modern vehicles, especially high-performance turbo-charged 4 and 6 cylinder gasoline and diesel multi-valve fuel injected engines including those found in passenger cars, light vans and trucks where a 0W-20 or 5W-20 viscosity grade is specified.

---

I guess I don't need to wait for data, huh?

 

[unDummy]

Its up to the automaker to decide what they want to recommend.

A nice oil cooler should take care of any temp problems. Water cooled turbo's are used pretty frequently now too, aren't they?

I know that Mazda is pushing 5w20. I wonder if Mazdaspeed is using it in the turbo Protege

 

[JohnBrowning]

Guys how much force do you think a 20wt can take before a rod bearing and crankshaft meet? Remember the oil has to seperate metal parts. With forced induction you have alot more load on the load bearing parts. I am also guesing that the oil system in the turbo charger acts like a continious low pressuer oil injector due to the size of the small oil passages, speed and heat(not implying that oil ever meets air). This by default will cause shearing.

THen you have all the long term data showing how most Turbo charged engines thrive on thick oils! I do not see an up side if you already have a winning combination!

 

[userfriendly]

John your right, it is up to the light weights to prove themselves, not the other way around.
I wonder if the 0W20 and 5W20 group IIIs that have very high flash points might work ok in a turbo application?
Perhaps even better than a PAO if I may be so bold.
The engine oil must provide lubrication and cooling both.
The high flow rate of a light weight engine oil may cool better than a heavier viscosity.
Rod and main bearing failures caused by a light weight engine oil can be corrected to some extent by engine design.
Fire away, I'm flame proof.

 

[unDummy]

Engine design?
Just drop the oil temp.
At what temps do the 20wt, 30....50wt, oils have the same viscosity?
For example, I'm guessing that a 20wt at 180F is pretty close to a 30wt at 210F or a 40wt at 240F.....
So, I don't believe all the "force" hype. Just make sure your oil capacity and oil cooling capability can maintain a certain temperature range.
Using thick oil because you have poor oil cooling or capacity seems, IMO, to be poor design.

An oil weight doesn't have to prove itself. An engine(oiling) design does!

One oil company had viscosity curves posted. I can't remember the brand but believe it was one of the boutique or european synth oils. Can't find the website right now. If I find it, I'll save the link.

 

[Rexman]

I asked our man Dave at Redline a while back about using the RL 5W20 in the WRX turbo. He said no--definitely not--stick with the 5W30 (or 10W30), which was kind of disappointing. (Ok, ok, I was hoping for a few extra horses by making the switch.

)

NEO has said their 0W5 will work fine in a turbo--said the engine will be a little noisier and to change the oil out every 6K rather than 15K. Otherwise, no problem.

Some guys on the board have thought the NEO might really be a 20 wt. with a very high film strength, so perhaps it's similar to the European 20s TooSlick spoke of earlier.

BTW, Fuchs is a very well-respected name in the auto industry overseas--they have been an alloy wheel supplier to Porsche for over 40 years--so their Titan synthetic might be just the ticket for going this route.

Wonder if it's available here in the States.

[ September 29, 2003, 08:27 PM: Message edited by: Rexman ]

 

[userfriendly]

Undummy;
What is "force" hype? High oil pressure?
The flow of oil into and out of the main and rod bearing clearance?
Can the engine actually pump oil out of the rod bearing clearance area?
If so, then would not a high volume of oil flowing into and out of the bearings be preferred to a heavier oil flowing into but not out of the bearing clearance area?
If the engine oil temperature was limited to say around 180-200F, could every automotive engine operate safely on SAE 10W?

[ September 29, 2003, 08:31 PM: Message edited by: userfriendly ]

 

[Rexman]

FWIW, here is a link to the Fuchs Titan GT1 0W20 page:

Fuchs Titan

Very expensive, but claims to be the first zinc-free synthetic to prolong life of catalytic converters. Also, rapidly biodegradeable and race-proven! Ran a 12-hour endurance race in Singapore without excessive oil consumption or over-heating-- and with below average wear on engine parts.

Another link of possible interest:
Porsche-Fuchs testing

[ September 29, 2003, 09:22 PM: Message edited by: Rexman ]

 

[userfriendly]

Thts not fair, they were using superior Far East group III+ base stocks.

 

[metroplex]

If you pick up a bottle of dino anything it will say that it's recommended for use in "high performance turbocharged engines" so any old oil is preferred in turbocharged motors? I think not.

If 5W-20 or 0W-20 synthetics were so good at reducing emissions AND could protect a turbocharged motor - why isn't anyone using it???

Is it because 0W-20 and 5W-20 can't handle the turbocharger temperatures??? I mean seriously - if the Subaru WRX STi could benefit from 0W-20 by reducing emissions AND protect the motor, wouldn't Subaru be using it?

Instead i'm reading about the use of xW-40 and xW-50 in these high performance turbocharged motors.

 

[timzak]

quote:

---

Originally posted by metroplex:
If 5W-20 and 0W-20 are "so great" for Ford's OHC V8s, why aren't they spec'd for use in engines like Subaru's turbocharged 2.0 and 2.5 motors or Porsche engines? They're also OHC but they just have turbochargers.

I would think the 20 weight can't handle the heat from the turbocharger.

What do you think?

---

Probably because different applications require different weights. If auto manufacturers can get away with a thinner weight to save fuel, they will. If they can't...

Sounds like someone's a bit peeved at 20 weights.

[ September 29, 2003, 10:19 PM: Message edited by: timzak ]