Dino,not Synthetic for Turbos

[BuickGN]

It really does depend on how it's driven and how often it's changed. Sure, oil picks up heat from the turbo but it's not that much. The extra heat from turbo motors comes from the extra power it makes. If you drive it easy and never use more hp to accelerate than it's NA cousin, synthetic isn't absolutely necessary.

As a daily driver my car never saw boost going to work and back unless someone wanted to play and that was only for a second or two. My oil temps are no higher than any normal NA car. Of course the potential is there to super heat the oil but I know better.

There is the issue of oil coking in the turbo after shutdown but that's not a big problem since most modern turbos are water cooled. In fact, when I pulled my non-watercooled turbo off after 200,000 miles and many hot shutdowns as a 17yr old, there was no noticable oil deposits in the bearings.

 

[Alan]

Flashpoints?

Mobil 1 5w30---446f

MC 5W30----430f

Hardly a difference.

 

[BrianWC]

Originally Posted By: Alan
Just got my first FI car,a Saab 9-5 SE V6 and it looks like it's been on conventional it's whole life however to my chagrin it looks very clean under the cap.

I am thinking about just keeping up with the conventional regime because of this and also seeing how close both conventional's/syn's are when it comes to flashpoints......why bother with a syn.

Who else uses conventional exclusively in FI app's?


Welcome to SAAB ownership. 9-5's are great driving cars. They are nice long distance cruisers and can carve up corners pretty well, too. The V-6 is not very moddable but it's a nice torquey motor right off the bat. This is not the same V-6 used in the newer cars. I believe it is the same family that was used in the Saturns of the same vintage. It was not explicity designed for forced induction so what's on there is pretty much the limit of what the engine can take. The V-6 is fairly easy on oil. I believe it's essential that you swap out the timing belt by the spec'd mileage, though. One of the earlier V-6's also needs it's timing belt pulleys swapped out, as well (or something like that). But I don't know if that extends to the 9-5.

I have a question about your original post. You say it "looks" like it's had conventional it'swhole life but is very clean. How do you know this? I only say that b/c if you bought it from a dealer they might have just done a cheapy conventional oil change to have fresh oil in the car. SAAB usually has only spec'd synthetic or synthetic blends for their cars. Most owners only use synthetic in these cars. I would go with the spec'd weight and no more than 5000 miles between changes.

 

[zoomzoom]

Originally Posted By: Alan
Flashpoints?

Mobil 1 5w30---446f

MC 5W30----430f

Hardly a difference.


It makes a big difference when oil goes trough 500-600F turbo bearing...

That MC spec is for their synthetic blend not dino...

 

[Eddie]

Excellent point zoomzoom.

 

[MolaKule]

Quote:
It makes a big difference when oil goes trough 500-600F turbo bearing...



Exactly. Each pass of a dino through that hot a bearing means coking particles getting into the oil. Coking particles are abrasive.

One could use a modern dino but the OCI shouldn't be over 2,ooo miles.

 

[GMBoy]

I see no reason NOT to run a Sythetic oil in any Turbo car(except BuickGN, I know why he does). You get better protection and with an extended OCI you can recover most of the initial cost over dino.

Just me and my opinion.

 

[BuickGN]

Originally Posted By: zoomzoom
Originally Posted By: Alan
Flashpoints?

Mobil 1 5w30---446f

MC 5W30----430f

Hardly a difference.


It makes a big difference when oil goes trough 500-600F turbo bearing...

That MC spec is for their synthetic blend not dino...


Do you know the bearings are that hot?

The center section gets plenty hot on a non-water cooled turbo.

Have you ever seen how quickly oil flows through a journal bearing turbo? When I forgot the return line one time I had 5 quarts of oil on the floor in 30 seconds. I'm not sure the oil picks up that much heat from the turbo itself.

The ball bearing turbos come with a restictor to limit oil flow. These *may* heat the oil more, I don't know.

I still stand by what I originally said that most of the additional heat in the oil comes from the extra power a turbo car makes.

With that said, I recommend synthetic in a turbo car.....except mine.

 

[Steve S]

Originally Posted By: MolaKule
Quote:
It makes a big difference when oil goes trough 500-600F turbo bearing...



Exactly. Each pass of a dino through that hot a bearing means coking particles getting into the oil. Coking particles are abrasive.

One could use a modern dino but the OCI shouldn't be over 2,ooo miles.
The worry with coking of the oil is on shutdown with a hot turbo.

 

[Steve S]

Originally Posted By: GMBoy
I see no reason NOT to run a Sythetic oil in any Turbo car(except BuickGN, I know why he does). You get better protection and with an extended OCI you can recover most of the initial cost over dino.

Just me and my opinion.
Not many really run the syn oil long enough for a payback. some do, most do not.

 

[BrianWC]

The SAAB's turbo is water-cooled. Still, synthetic is a good thing in SAABs.

 

[Ken2]

The flash point is the temperature the oil bursts into flame. That does not exactly relate to the temperature the oil bakes into carbon. The point of using synthetic oil in a turbocharger is to have an oil that will handle the heat, especially the heat after a hot run when the engine is immediately shut down, and not cook into carbon in the turbocharger bearings or carbon that clogs the oil passages, VW style. I know, most turbochargers in the world have conventional oil...every truck, ship, locomotives, rail engines, tug & fish boats, construction engines, etc., etc., but these turbos are made for long life generally with trained operators. Automotive turbos are made to be small and peppy.

 

[zoomzoom]

Originally Posted By: BuickGN
Originally Posted By: zoomzoom
Originally Posted By: Alan
Flashpoints?

Mobil 1 5w30---446f

MC 5W30----430f

Hardly a difference.


It makes a big difference when oil goes trough 500-600F turbo bearing...

That MC spec is for their synthetic blend not dino...


Do you know the bearings are that hot?

The center section gets plenty hot on a non-water cooled turbo.

Have you ever seen how quickly oil flows through a journal bearing turbo? When I forgot the return line one time I had 5 quarts of oil on the floor in 30 seconds. I'm not sure the oil picks up that much heat from the turbo itself.

The ball bearing turbos come with a restictor to limit oil flow. These *may* heat the oil more, I don't know.

I still stand by what I originally said that most of the additional heat in the oil comes from the extra power a turbo car makes.

With that said, I recommend synthetic in a turbo car.....except mine.


Ok guys here is the graph that shows how hot is the exhaust side of my turbo under load.

Temperatures reach 800C by the redline...I don't know about him but I want good synthetic oil lubing my turbos

 

[Alan]

Originally Posted By: zoomzoom
Originally Posted By: Alan
Flashpoints?

Mobil 1 5w30---446f

MC 5W30----430f

Hardly a difference.


It makes a big difference when oil goes trough 500-600F turbo bearing...

That MC spec is for their synthetic blend not dino...


If either just sat in the 500-600 degree bearing they would both coke.With good flow dino will suffice.

The 430f spec is for the $12 a 5qt jug at WW.It's the basic MC 5W30.

EGT does not directly translate into oil temperatures.

 

[Alan]

Originally Posted By: Ken2
The flash point is the temperature the oil bursts into flame. That does not exactly relate to the temperature the oil bakes into carbon. The point of using synthetic oil in a turbocharger is to have an oil that will handle the heat, especially the heat after a hot run when the engine is immediately shut down, and not cook into carbon in the turbocharger bearings or carbon that clogs the oil passages, VW style. I know, most turbochargers in the world have conventional oil...every truck, ship, locomotives, rail engines, tug & fish boats, construction engines, etc., etc., but these turbos are made for long life generally with trained operators. Automotive turbos are made to be small and peppy.


VW design caused their turbo problems,the longitude had them and the transverse mounted ones didn't.

Dino is a sensible design is fine.

 

[Alan]

Originally Posted By: Steve S
Originally Posted By: MolaKule
Quote:
It makes a big difference when oil goes trough 500-600F turbo bearing...



Exactly. Each pass of a dino through that hot a bearing means coking particles getting into the oil. Coking particles are abrasive.

One could use a modern dino but the OCI shouldn't be over 2,ooo miles.
The worry with coking of the oil is on shutdown with a hot turbo.


I think that worry is unfounded in most applications.

 

[zoomzoom]

Originally Posted By: Alan
Originally Posted By: Ken2
The flash point is the temperature the oil bursts into flame. That does not exactly relate to the temperature the oil bakes into carbon. The point of using synthetic oil in a turbocharger is to have an oil that will handle the heat, especially the heat after a hot run when the engine is immediately shut down, and not cook into carbon in the turbocharger bearings or carbon that clogs the oil passages, VW style. I know, most turbochargers in the world have conventional oil...every truck, ship, locomotives, rail engines, tug & fish boats, construction engines, etc., etc., but these turbos are made for long life generally with trained operators. Automotive turbos are made to be small and peppy.


VW design caused their turbo problems,the longitude had them and the transverse mounted ones didn't.

Dino is a sensible design is fine.


what does the owners manual recommend?

 

[zoomzoom]

Looks like Saab recomends syn oil for its cars... you can read up on details here: http://www.genuinesaab.com/psi/files/03oil-service.htm

 

[Alan]

Originally Posted By: zoomzoom
Looks like Saab recomends syn oil for its cars... you can read up on details here: http://www.genuinesaab.com/psi/files/03oil-service.htm


Another design issue,not an oil issue that caused sludge that afflicted many late 90's to early 2000's 4cyl Saab's.The syn recommendation was really just a band aid fix.

The V6 Saab's from the same era have no sludging problems whatsoever with just regular conventional oil changes.

 

[BrianWC]

Alan I urge you to go to saabcentral.com or saabnet.com and ask v-6 9-5 owners how many of them run dino.