Shear stability in a turbo

buster · Aug 15, 2003

Thanks! You even did the math.

Mitsubishi went with Mobil 1 10w-30 for there Lancer/Evolution. Makes sense. The WRX and Lancer have to be two of the ugliest cars out there today. Fast though! Redline and Amsoil, IMO, are not more shear stable then M1 even though they have better HT/HS numbers. I think there is more to it then that.

[ August 16, 2003, 01:04 PM: Message edited by: buster ]

WeyounDS9 · Aug 15, 2003

A freind of mine with a 2k3 lancer Evo VIII was complaing about his oil getttign beat up real quick, in his car (10w-30 or 5w-30 MOBIL1).

I told him to switch to 15w-50MOBIL and aboslutely no problems since oil looks new or newer for the entire drain interval where as teh thinner gradees blackned within a couple of weeks.

Driving habits are same for all fill (that is to say hard to include summer autoXing.)

Fred..

Cary · Aug 15, 2003

It's only one data point with the redline, but crap, there goes the arguement that it is shear stable. It will be nice to see some more UOA's so we can get some statistically valid data. I don't know who said it in response to my concerns about M1 0w-40 stability, but he may be right that it is just stable as any other oil.

Cary

buster · Aug 15, 2003

quote:

A freind of mine with a 2k3 lancer Evo VIII was complaing about his oil getttign beat up real quick, in his car (10w-30 or 5w-30 MOBIL1).

How does he know it's getting beat up quickly? Did you sample it? I think it's a matter of time before Mobil has to thicken up there oils a bit to a A3 rating. We are seeing many Turbo 4cyl engines now from various makes that are really hard on oils. Much more hard then LS1's.

pscholte · Aug 15, 2003

quote:

Originally posted by Cary:
It's only one data point with the redline, but crap, there goes the arguement that it is shear stable. It will be nice to see some more UOA's so we can get some statistically valid data. I don't know who said it in response to my concerns about M1 0w-40 stability, but he may be right that it is just stable as any other oil.

Cary

Cary,

I'm not a Redline user but it didn't do SO badly...granted in this one sample it didn't show the promise of all the talk that often surrounds it, but it wasn't a disaster. Your last statement is really important...maybe when the number crunching is done, M1 0W40 doesn't do that badly either...

Patman · Aug 15, 2003

quote:

Originally posted by Cary:
It's only one data point with the redline, but crap, there goes the arguement that it is shear stable.

Their 10w30, 5w30 and 10w40 are all extremely shear stable though. I don't think anyone makes a 5w40 or 0w40 that will stay perfectly where it started out viscosity wise.

jsharp · Aug 16, 2003

Ok, someone point out what I'm missing here. When we look as Turbo engines, I'd think the main problem would be high temperatures seen in the Turbo bearings, not "shear."

Shear issues would be more prone to show up in engines like Toyoyas with gear driven camshafts or in motorcycles with shared engine/transmission sumps.

Are the viscosity changes we're looking at here a product of "shear," or something else?

[ August 16, 2003, 04:50 PM: Message edited by: jsharp ]

Pablo · Aug 16, 2003

Mr. Sharp - You are on to something. Heat oxidation damage vs. mechanical shearing. Along the sames lines - and I really want to thank quadrun for digging the data

- I think it varies a LOT by driving habits and turbo/engine design. I mean a non-water cooled turbo that is driven yellow hot and immediately shut down is much harder on the oil than a water cooled turbo that has plentiful idle down.

Don't try this with dino oil.

Tyrolkid · Aug 16, 2003

Ive posted a few Redline 5w-40 analyses on turbo VWs. Search my username. I will be posting my 3rd this evening......

javacontour · Aug 16, 2003

quote:

Originally posted by Pablo:
Mr. Sharp - You are on to something. Heat oxidation damage vs. mechanical shearing. Along the sames lines - and I really want to thank quadrun for digging the data

- I think it varies a LOT by driving habits and turbo/engine design. I mean a non-water cooled turbo that is driven yellow hot and immediately shut down is much harder on the oil than a water cooled turbo that has plentiful idle down.

Don't try this with dino oil.

You guys make me feel so much better about my 98 SVT Contour that I just turbocharged.

(Whoo hooo 250HP at the Front Wheels outta 2.5L)

Of course, I still need to get the tuning right as it is way rich over 3500 RPMs.

However, that T28 is fed by both coolant and oil.

It survived the trip from Phoenix, back to STL, even on the crappy 90 octane fuel east of Albuquerque, with me saying, "stay outta the boost, stay outta the boost"

Probably gonna run some Mobil 0W40 now or the 5W40 fleet oil (that I can't remember the name), just for some extra piece of mind.

I try to drive that last mile home at under 3K RPMs to let the turbo cool off, so I don't have to sit and idle in the driveway for a long time

TB

harrydog · Aug 16, 2003

I agree with Patman and I really can't understand why anyone would want to use Redline 5w40 in a turbo engine when they have 5w30, 10w30 and 10w40 that are all probably better choices, depending on the situation.

jsharp · Aug 16, 2003

quote:

Originally posted by Tony Boner:
You guys make me feel so much better about my 98 SVT Contour that I just turbocharged.

(Whoo hooo 250HP at the Front Wheels outta 2.5L)

Of course, I still need to get the tuning right as it is way rich over 3500 RPMs.

I'll reiterate what Pablo said "Don't try this with dino oil."

Jelly · Aug 16, 2003

quote:

Originally posted by jsharp:

quote:

Originally posted by Tony Boner:
You guys make me feel so much better about my 98 SVT Contour that I just turbocharged.

(Whoo hooo 250HP at the Front Wheels outta 2.5L)

Of course, I still need to get the tuning right as it is way rich over 3500 RPMs.

Click to expand...

I'll reiterate what Pablo said "Don't try this with dino oil."

Ahhhh, it's good to be back...been gone a couple of days.

Since I'm currently using Delo 400 in my truck, I have to ask: Why don't you all believe one of the "dino" HDEO's (Delo, Delvac, Rotella, Long Life) couldn't stand up to high-rpm turbo use?

[ August 16, 2003, 09:28 PM: Message edited by: Jelly ]

quadrun1 · Aug 16, 2003

I decided to check out the viscosities on UOAs for turbos and compare them to the VOAs, here's what I found. (nb: Numbers not perfect! In some cases I couldn't find a VOA from the same lab, so I had to use the manufacturer's spec sheet.)

10W-30 does appear to be the most shear stable in the Mobil 1 line; the one Delvac 1 UOA we had didn't look so special, and I'm not convinced that Amsoil and Redline are super-shear stable either... but I definitely will give Amsoil a try in my turbo one day!

Let me know if I missed any interesting turbo UOAs or made any errors; looking forward to your comments.

Car/oil/mi, UOA, VOA, % visc loss/gain

Audi 2.7T, M1 0W-30, 5,347 mi 59.3 61.8 4% loss
SAAB 9000, M1 15W-50, 6300 mi 82.2 89.1 7.7% loss
SAAB 9-3 Turbo, M1 0W-40, 4718 mi 11.7 14.9 21.5% loss
SAAB 9-5 Aero, M1 0W-40, 4833 mi 66.4 72.7 8.7% loss
Volvo 940T, M1 0W-40, 3600 mi 66.6 72.7 8.4% loss
Audi TT, M1 5W-30 vs 0W-40 0W-40:9.5% loss at 5K, M1 5W-30:1% loss at 5K, thickened 11% at 10K
Subaru WRX, M1 5W-30, 7183 mi 57.8 60.3 4.1% loss
Subaru WRX, M1 5W-30, 4888 mi 58.5 60.3 3% loss
SAAB 9-3 Turbo, M1 10W-30, 5500 mi 57.8 58.3 1% loss
Volvo 940T, M1 10W-30, 3600 mi 60.6 58.3 thickened 3.9%
Subaru WRX, M1 10W-30, 5427 mi 59.1 58.3 thickened 1%
Supra twin turbo, M1 10W-30, 2325 mi 60.5 58.3 thickened 3.8%
SAAB 9-3, Delvac 1 5W-40, 6250 mi 13.9 15 7.3% loss
Audi S4, Amsoil 0W-30, 6800 mi 12.3 11.3 thickened 8.8%
Audi TT, Amsoil 10W-40, 5500 mi 12.5 14.0 10.7% loss
Volvo 240T, Amsoil 10W-40, 7500 mi 14.8 14.0 thickened 5.7%
Subaru WRX, Amsoil 10W-40, 3148 mi 13.46 14.0 4% loss
Subaru WRX, Redline 5W-40, 3023 mi 73.1 80.2 8.9% loss
Subaru WRX, Schaeffer's 701 5W-30, 7000 mi 11.61 10.07 thickened 15.3%
Subaru WRX, Royal Purple 10W-30, 5000 mi 6.6% loss

Jason

quadrun1 · Aug 17, 2003

The heavy duty fleet oils probably could manage okay, after all, aren't most rigs turbocharged? But perhaps those things run lower exhaust and turbo temps. Also, they have HUGE sumps.

But 15W-40 might be too heavy for people who experience cold winters. I think most turbo 4 cyl gas engined cars spec 0W- and 5W- oils, except the Lancer as mentioned above.

Not so long ago, they used dino oil in turbo SAABs but they also recommended a "cool down" procedure before shutdown. The newest SAAB (9-3SS) calls for fully synthetic. There have been some problems with the semi-syn oil in the 9-5--only fully syn for me!

As for heat damage vs. mechanical shearing, that's a good point! Definitely there's lots of heat in a turbo, but also, don't those things spin at hundreds of thousands of RPM?

[ August 17, 2003, 02:14 PM: Message edited by: quadrun1 ]

Rexman · Aug 17, 2003

quote:

Originally posted by Buster:

The WRX and Lancer have to be two of the ugliest cars out there today. Fast though!

The WRX and Lancer look like tough little street fighters, IMO--very distinctive and original, along with the new STi. At $24-$30K, they are true value bargains when you consider the world-class performance they deliver-- comparable to many BMW's, Audi's, and Porsches costing twice as much.

P.S. The real beauty of these rally-inspired cars can only be appreciated on a winding and twisty road, from the driver's seat looking out--and the tach needle repeatedly hitting the redline at 7K!

[ August 17, 2003, 03:09 PM: Message edited by: Rexman ]

darrenc · Aug 18, 2003

Here is some more to add. From my 99 Volvo S70 T5.

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=000298#000000

Doug Hillary · Aug 18, 2003

Hi,
yes, all heavy trucks are turbocharged most equipped now with a wastegate too. Exhaust gas ( pyrometer ) readings go up to 700f on long climbs. Oil temps are up to around 115C at this time. Normal oil temp. in my 500hp Detroit 60 series engines is around 95C
Oil capacity is around 38 litres and all have an oil intercooler
Mobil's Delvac 1 5w-40 is an excellent oil in both highly stressed petrol engines and for where it is designed - heavy diesel engines. It actually exceeeds ACEA A3/B3 although it this not stated. It is of course a CI/SL oil. It maintains it's viscosity for over 120000kms and has an excellent HT/HS rating
I have used this oil for millions of kms in heavy and light diesels and in petrol engines too

Regards

Shear stability in a turbo

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