M1 0W-40, '99 Saab 9³, 2.0L turbo, 14 months/8,800 miles

[Eiron]

Hey guys, thanks for the comments!

Finklejag,
Yes, I think the Saab 0W-30 is an excellent oil, but perhaps not the best choice for a Saab turbo engine. A couple of things to remember:

1) Up until the release of the '03 9³ SS (& subsequent introduction of a fully synthetic oil in the US), Saab's primary recommendation for all turbo engines was an oil meeting ACEA A3. This new oil only meets ACEA A5 (unlike the other GM-LL-A-025 approved oil for US models, M1 0W-40). I suspect CAFE is the reason, since Europe still gets a Saab 0W-40 full syn.

2) This new engine has a 50% larger oil capacity than mine (6L vs 4L), so yes, stretching the OCI to 15k mi is a no-brainer for this model. I'm guessing the oil will last maybe 2X longer than in my car, since the heat & shearing abuse will be spread out & keep it "fresher". The extra additives also help it out here.

A turbocharger (& perhaps a Saab turbo in particular) is the embodiment of the term "High Temperature/High Shear." With only a 4L oil capacity, there's no way I want to use an oil with a low HT/HS rating. I agree with you, that this new Saab 0W-30 is a great oil, but I see it as being better for their non-turbo & diesel models.

Primus,
Dude! Glad to see you're still with us! Yeah, it's a little confusing for me as well. I've been using the same lab for all of my UOAs & VOAs. I suspect that the mixing of oils had something to do with the odd pattern in the additive numbers. (Maybe the milk jug added "extra nutrients"? OK, just kidding!) Maybe Mobil had a formula change? The oil I used came from a number of different stores & it was all loose bottles, so I'm sure none of the five bottles I used came from the same batch.

I asked the lab about the Oxi/Nit/Sul numbers, & they described it this way:
"Oxidation/nitration/sulfur products are based on how the engine is running. Factors that effect them are application, cooling system condition, topping off with a another oil, changing oil brands, temperature, etc. They change every time. We don't really trend them; they are more a snap shot of the engine at that specific time."

Does this info help?

 

[mnztr]

Erion, I looked at your test and I wonder if going with a thicker oil is the right direction? Frankly the type of driving you do, I doubt the oil ever gets that hot, so why the concern with high temp viscosity? Perhaps consider trying a thinner oil, 0W30 or so. The high PB might be due to the many cold starts, using a thinner oil may help the oil get there quicker.

 

[jthorner]

From what I see I think you are nuts to be trying to go for such extended drains. What exactly is the point?

Iron and Lead numbers are high. This is an expensive motor in an expensive car.

Personally I think that you are overthinking and overcontrolling this situation. A good middle of the road oil like Shell Rotella T synthetic changed every 5,000 or so miles is likely to protect your expensive engine and turbo charger while allowing you to get contaminants out on a regular basis. $13/gallon for the oil plus $4 for a good keeps you under $20 per oil change.

Why mess around?

John

 

[Eiron]

Hi mnztr,

This is already a 0W- oil, so I'm not sure how much I'd gain by going to a different 0W- oil.

I do agree that any 0W-30 will have slightly better cold-flow than a 0W-40, but since I'm already down to a 0W- I'm just not sure if I'd actually see any difference.

A lot has been said recently about M1's "false high" iron readings, but I haven’t taken the time to wade thru all of it. I'm really looking forward to seeing how a non-Saab oil (quadrun1's UOA on GC) shows in a Saab turbo in a similar climate. (I just wish it was a real test by going a full year/10,000 miles! :wink: )

The 5W-40 has an additive package & vis range which more closely matches Saab's OE oil "history" (that is, combined gas/diesel engine approval), so I'd like to give this a try before moving on to a anything different. Your suggestion is definitely something to keep in mind, though.

Hi jthorner,

The point was "to get a general idea of how well the 0W-40 would hold up over 10,000 miles" in my car under my conditions. And I completely agree with you, "this is an expensive motor in an expensive car." But I also believe that we're not exploring the true potential of any of these oils to protect our engines. If Saab can recommend 10k mi OCIs under "normal" conditions using a semi-syn, then I fully believe I can go the same distance under "severe" conditions using a premium full syn. The latest Saab turbos, armed with a 50% oil capacity increase & GM’s syn-programmed OLM, can go a maximum of 2 yrs/18k mi on the required full syn.

Your point about the Fe & Pb numbers has not escaped my notice. It's common for these engines to show high Fe & Pb numbers, but I think mine are a little higher than average. Since the oil itself still looks OK (decent additives & viscosity, no moisture or fuel or glycol, low oxi/nit, good TBN), I have to wonder how much of the trace metal count is due to the prior oils?

We bought the car when it was 2 yrs old & had 16k mi on it, & I have no idea what it was using before we found it. I had the Saab dealer change the oil & it was supposed to be Castrol 10W-30 semi-syn (I paid them extra for it). I later found out they used Valvoline 5W-30 bulk oil in everything they serviced, & I’ve recently learned they are frequently less than honest. (What?!?

) At 20k mi I switched it to Syntec 10W-30 & ran two 10k mi OCIs. In both intervals, the car used no oil over the roughly 12 mos it took us to go 10k mi. I never ran a UOA during these intervals, so I have no idea what the trace metal content looked like at that time.

The 0W-40 formulation of M1 meets GM's new "Long Life" spec, so it's got a ton of engine cleaners in it. If it’s clearing out crud left behind by whatever else was used, then it’s not an accurate picture, right? This is partly why I decided to run A-Rx at this point. In addition, I’ve decided to run a short rinse with the M1 5W-40 after the A-Rx is done, so it’ll be a more accurate representation of what the oil can do during a full interval. I believe my next UOA will show better than this, but we'll have to wait & see.

Thanks for the concern.

Other than shortening my intervals & artificially reducing my counts (Fe was the only element which more than doubled between UOAs this interval), is there anything else you’d recommend?

 

[mnztr]

You have to remember that 0W only represents the viscosity at 0 degrees C. If I were to make an educated guess, below and above this temperature, a 0W30 or 0W20 would be much thinnner then a 0W40. Even at 0 degrees, the 0W20 would be at the thinner end of the 0W range. For your type of driving I would try thinner. I use 0W40 on my 93 (for the first time this year I used to use 10W30) and I am satisfied but will do a UOA when my change comes. I typically change every 10000km for convenience. Also, how about this trick....keep your oil at the lower end of the Saab dipstick to accelerate warming in the winter. Persoanally I wouldn't try it myself ;>), but I wouldn't go 9K miles either.

 

[Eiron]

Yes, I agree, a 0W-20 or 0W-30 probably is a bit thinner than a 0W-40 at 0°C. This would give me better flow when it's cold, but considering our climate throughout the entire year, probably only 20% (or less?) of our starts are at (or below) this temp. Summers here always get up around 40°C, so I think I have to give more weight to warmer weather.

Because of the car's 4L oil volume & the stress the turbo places on the oil, I'm still not comfortable with the idea of using a low HT/HS oil (that is, something either ACEA A5 or A1 rated).

I wouldn't hesitate to run this 0W-40 oil out to 20,000 km in a n/a Saab engine. Maybe even 30,000 km if UOA showed it capable (on only 4L of oil). And like you, I'm not willing to run my oil at the low end of the dipstick.