which oil for 3K intervals

[greenhobby]

Hi,

I have a 98 Saab SE Turbo 900 tuned out to about 300 HP. New ECU, exhaust, intake, bpv, etc. It runs great. I have switched from Mobil 1 to Amsoil 5w40 European stuff 'cause it's supposed to last a bit longer. At 3K it is black and pressure is way down!! These turbo's run really hot and the stock exhaust/cat is right under the pan. Since I have to change it out at 3K is it worth putting extended life oil in the engine? Would lesser oils not last 3K? Mobil 1 (cheaper) seems to last just as long (3K). I haven't done testing on the oil, just going by color and pressure.

thanks in advance for helping.
-greenhobby

 

[Pablo]

"Pressure is way down"?

Hot? Cold? Idle?

I rarely see Amsoil thin in application. I'm not just saying this - it's really infrequent.

Is this your first cc of AFL? Black oil because of heat? Or cleaning? Or the enrichment circuits?

It runs great. The car is tuned to 300HP. It's a 2L or so, right? That's going to be hard on any oil, but only a UOA will tell the truth.

 

[BrianWC]

Hmm, greenhobby, are you on SC or TSN?

How are you measuring the pressure? What's the variation? Which Mobil1? If it's a NG900 and not a 9-3, you shouldn't HAVE to change it out at 3k. 'Course with the mods....

 

[hominid7]

You changed oils and the new oil is cleaning some gunk left by the other oils different chemistry.

Stay with Amsoil one more OCI and see what happens. If you get a repeat, switch back to Mobil1, but my guess is this go-round you will see some improvment.

Due to availability, i would tend to stick with M1 however.

 

[BrianWC]

If you're running it off boost mostly, most folks go with either M1 5W30 or the recommended 10W30. Some go up to the 15W50 but it that's up to you-I don't think I'd do it in winter regardless up there.

Many of us 9-5'ers have gone with Rotella T Synth 5W40, especially since M1 Truck and SUV disappeared in that viscosity. German Castrol Syntec would also be great in that app. DickinFallsChurch is also an Amsoil guy (no offense to you, of course, Pablo) who is a Saab owner. He may have some insight into what he runs in his car. I've never run it so I can't dare give an insightful recommendation.

Of course, redline is also used by more than a few folks...

Now that I've named just about every oil.....

 

[greenhobby]

Thanks for the replies...

Pablo, I've seen about 3-5 PSI reduction (5 when cold). This was the first time I've used Amsoil. I ran a can of the AMsoil flush through the engine as the directions said before I filled it with 4 liters of the 5w40. Yes it is a 2.0 (B204) liter engine. I usually wait until I get 2-4 psi reduction at 2K RPMs to change (and of course color).

Brian, I did 3 oci's with Mobil 1 10w30. Was using Castrol (almost syn) for 8 years before (every 4-5K). I dropped the pan when I started tuning it and it didn't have a drop of sludge. Perfectly clean. It looks like the Castrol was keeping it clean. I wanted to start using 100% synthetics when I tuned it. Yes I'm on SC and TSN. They are great forums. Got lots of ideas and help from those folks on tuning the Saab.

I just did an oil change and put fresh Amsoil in there. I'll keep an eye on it.

thanks again for the replies,
-greenhobby

 

[greenhobby]

Sorry, I didn't answer all the questions:
I'm using an autometer electric oil pressure gauge. It is pretty dead on. I goofed when I said the pressure was way down. What I meant was that it was down enough for me to want to change the oil. My point of the sentence was that I was surprised that a 15k oil was in need of change at 3k.

The car seems to love the stuff. I'm just curious if I need to spend the extra money on extended oil in my application. I really don't mind changing it either.

-greenhobby

 

[BrianWC]

Yeah but if you're basing it soley on color, you could be mislead. Some oils just blacken quicker. Frankly, in my saabs, the only oil I haven't seen jet black within a matter of miles was Pennzoil Platinum. I've never run a pressure gauge on my saab so I don't know how the oil acts pressure-wise over its life. 3-5 psi shouldn't be a huge deal if your still in the range. The WIS should have the PSI ratings if you haven't checked.

There could be a difference in chemistry in the AMSOIL enough to be cleaning up whatever slight deposits you may have not noticed.

One more thought, you may have a little more fuel dilution if your running more boost and fuel on the stock pistons. How many miles on the engine?.

And who are you on SC?

 

[grbr95]

Castrol GTX... It has a unique anti-sludge formulation..hehehe.

 

[Pablo]

If you used the Amsoil flush, your answer might be right there. I never recommend much beyond 3K after running the flush. You had some cleaning and flushing going on.

Since you changed the oil, as you say just keep an eye on it.

 

[greenhobby]

Brian, I just turned 80K on the engine. Actually I used the WIS to determine the correct pressure. It is easy to determine when I need to change. At 2K RPM when warm, it sits at 37 PSI just after oci. When it gets below 34-33 PSI, I change it. wrt SC, I'm greenhobby there as well.

I'm certain that there were some deposits in the engine prior to the flush. When I emptied the flush it was a nasty color. Pablo, that makes perfect sense that there is more cleaning and flushing going on with the subsequent oci.

thanks,
-greenhobby

 

[BrianWC]

Cool. One more reason for me to install that oil pressure gauge. I like Pablo's idea about the flush. You may also do a compression test, though, if you haven't already.

 

[TooSlick]

I'd recommend running the new Amsoil 10w-40 Motorcycle oil. It's going to be more shear stable then their new 5w-40,is better suited for a very high temp application and is significantly thicker in terms of HT/HS viscosity, ie 4.5 Cp vs 3.7 Cp @ 150C. The pour point of this formulation is about -50F, so no problem with using it year round.

The MC oil is more expensive then the 5w-40, but I believe you'll be able to get at least 5000-6000 miles of use out of it. It's an 11 TBN formulation and is SL/CF rated for use in automotive gas engine applications.

TS

 

[memo]

Have you tried Mobil 1 15w 50 yet?

Some info

 

[BrianWC]

Oh what a tangled web we weave....

This is a Saab B204L longblock and if you don't have one your comments are useless. I've had two so that makes me more qualified than anyone here and if you disagree with me you're a post troll.

That was a joke.

Those it was meant for got it.

 

[memo]

At least I didn't tell the saab owner he was throwing his oil away at 3K miles.

If you have a problem with me suggesting Mobil 1 15w 50 and it not being up to the tast, go email mobil 1 and take it up with them.

That last thread got locked cause you just couldn't shut up. Let's not start that again!!!

 

[BrianWC]

 

[BrianWC]

The last thread got locked because I reported it.

M1 15W50 is great in this app, just like I suggested several posts ago.

 

[sxg6]

quote:

---

Originally posted by memo:
Have you tried Mobil 1 15w 50 yet?

Some info

---

This is the second thread i've seen you suggest m1 15w-50, why do you like these thick oils so much? A 5w-40 would work just fine. M1 ep would be a complete waste of money with a 3k oci

 

[JAG]

I bet this pressure drop over time is mostly from fuel dilution, not oil shearing. Do a UOA at 3k miles and you'll find out the answer!