What's the coldest anyone's using Mobil 1 15w50?

[Eiron]

A friend in Denver has Mobil 1 15W-50 in his '93 Audi S4 (5 cyl turbo). The car usually goes from enclosed parking at home to enclosed parking at work, so even in the dead of winter it never sees startup temps much below freezing. He mentioned wanting to take the car on ski trips (since it's AWD), but was concerned about Mobil 1 15W-50 startups below 0°F when up in the mountains.

I told him my neighbor parks his Mitsubishi 3000 GT biturbo outside & uses Amsoil 20W-50 year-round in it (with quite a few startups below 0°F this year). I thought his S4 would be fine for the occassional cold startup in the mountains, but he still sounded hesitant.

Anyone have experience with Mobil 1 15W-50 startups at or below 0°F?

 

[Ugly3]

0 degrees F is well below the optimal temp to start up with 15w50.

 

[OldCars]

Well the only thing I use it for is for my Toro 8hp snow blower. One thing which is apparent that it starts up a lot better in cold than the factory recommended straight 30w oils.

 

[Palut]

A good 5W-40 would be a great winter replacement for 15W-50 wouldn't it?

 

[BlazerLT]

I am venting here, but what is it with people using 15w oils anyways?

What is the point of it?

Does an Audi really require a 50weight oil?

 

[Dr. T]

Blazer, I know it's hard to comprehend. Unless you own/owned a Euro. vehicle you won't be able to appreciate why these weights are recommended, used and often required for these cars.

Like I've said before, viscosity SHOULD be TEMP. based only....not "use 5-20/5-30 for all temps". In other words, each grade has a temperature range for which it is acceptable. It's not an "engine" thing either. TEMP. only.

That said, my owners manual (`94 BMW) stipulates that a 15w40 or 15W-50 can be used down to -20C (whatever that is in F). It then goes on to say that "the temperature can go below or above the recommended range for short periods without problems".

I've used Mobil 1 15w50 down to -22.5C (as read on the dashboard computer). I believe Mobil's website comfirms borderline pumping down to -37C with this grade. Probably due to it's synth. nature, it can remain adequate for starting down to this temperature.

 

[Al]

Well 15W is rated at 3500 cP @ 5 F . I'm sure it will start with effort at -10F or so. But its just not a good thing to do. 5F would be a practical limit (to me).

 

[Cary]

I cold started at 5f after sitting overnight in Tahoe one time with my old BMW. It took about 6-7 long seconds for the oil pressure light to go out with the 15w-50 oil at that temp.

As a long time german car owner, it is not necessary for your friend to use 15w-50 unless he is tracking the car. The new 0w-40 and 5w-40 synths are great and are what is recommended. In fact Porsche specifically recommends the use of 40 weight synthetics. The reason that 20w-50 used to be used was due to breakdown of mineral oils at high operating temps when run hard on the autobahn. Modern oils do not have that problem.

Look at almost all the Europeon specs for cars used in Europe. BMW, Mercedes, BMW, Audi, VW, Austin Martin, Porsche, etc, almost all recommend light 40 weight or heavy 40 weight oils that meet ACEA A3.

 

[dickwells]

My old 79 chevy truck 350 was no go at =10 but popped right off as soon as it got above 0. Of course that was several iterations ago of Mobil 1.

 

[JohnBrowning]

Erion, I would recomend that he swith to Mobil 1 Truck and SUV 5w40. I can say that since my Father retired from the Army a few times he has left 15W50 in due to lack of time to change it well into a Michigan winter. One time he returned from a run and we had a record cold snap. WHen he left the lows were like 25°F when he returned from his run it was -22°F! I told him to wait and we could change the oil to a 10W30 before he started it up. He did not want me working on his truck outside in that weather. So against my better judgment he started it up. It turned over a bit slow but it did fire. His oil light went out right a way. His engine did sound different though for a few seconds!!He know has well over 120,000 miles on it I think it closeing in on 150,000 miles and it still does not burn any oil! I would never recomend 15W50 for winter use in a cold climate! I am not saying it can not be done but common sense should prevail. A 5W40 like Mobil 1 Truck and SUV will work every bit as well dureing the winter as any other 5W oil and will still give him good protection at temp.!

 

[1maniac]

I used to run Mobil 1 15w50 in my BMW before I found this site. Manual reccomends conventional 20w50 or BMW "Special Oil" which is their 0w30 synthetic. In the winter it starts a whole lot easier with the Redline 10w40 in it then it did with the Mobil 1 15w50.

 

[jthorner]

There is no way I would be using 15W-50 in the winter in Denver. Yikes. Even with a Euro vehicle I would be using either 5W-40 or 10w30 if I were doing the synthetic thing there in the winter on the '93 Audi.


John

 

[Dr. T]

Cary, Porsche recommends both the 0-40 and the 15-50. I spoke to a Porsche mechanic 2 years ago right at the service bay at a local dealer. He tells me "the new ones get the 0-40, and the old ones get 15-50".

The 15-50 is simply the "synthetic" version of the tried-and-true 15w40 conventional that is often praised here and is the commercial fleet oil grade.

 

[Steve S]

quote:

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Originally posted by Ugly3:
0 degrees F is well below the optimal temp to start up with 15w50.

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Remember that a syn oils cold weather performance is different than a petro oil. It would be nice if there was a recommended temp chart for syn oils like there is for petro oils.

 

[Dr. T]

Because a 15W is still a 15W...doesn't matter if it's conventional or synthetic other than to say there is some minor leeway of safety.....

In other words, the engine may actually start whereas the dino would be more of a block of ice

 

[Cary]

quote:

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Originally posted by Dr. T:
Cary, Porsche recommends both the 0-40 and the 15-50. I spoke to a Porsche mechanic 2 years ago right at the service bay at a local dealer. He tells me "the new ones get the 0-40, and the old ones get 15-50".

The 15-50 is simply the "synthetic" version of the tried-and-true 15w40 conventional that is often praised here and is the commercial fleet oil grade.

---

There was an extensive article about this last year in one of the Porsche Magazines. It quoted directly the Porsche memo and the approved oils. Porsche approves many oils (but only synthetics now) including your favorite the Castrol TWS 10w-60, but their primary recommendations are the 40 weight oils.

 

[C4Dave]

A buddy started up his 302 Mustang with Mobil 1 15w50 when the temp was in the teens. He revved the motor a little (a lot, actually), and the oil light came on. Tear down revealed that the oil pump drive shaft twisted like a barber pole and then snapped in half. YMMV.

 

[OldCars]

quote:

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Originally posted by C4Dave:
A buddy started up his 302 Mustang with Mobil 1 15w50 when the temp was in the teens. He revved the motor a little (a lot, actually), and the oil light came on. Tear down revealed that the oil pump drive shaft twisted like a barber pole and then snapped in half. YMMV.

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All that proves that Fords suck

But seriously it is an indication of poor engine structure. My '88 Porsche Turbo was using 20w-40 oil thick enough to keep the oil pressure very high until about 20 minutes of driving. I could rev it past 6000 RPM effortlessly without any problems.

 

[Eiron]

Thanks guys!

This S4 turbo's brand new to him this past Sept. He bought it with 67k mi on it & he's only put about 3k miles on it since then. He wasn't 100% sure what had been used prior, so he put the Mobil 1 15W-50 in there for the best protection. Looking thru his owner's manual, Audi's oil recommendations definitely run towards the heavy end of things. IIRC, they didn't want you to run any xW-30 in temps higher than 60°F, & everything between 10W-40 thru 20W-60 was preferred. Synthetic was mentioned but not required or even strongly recommended (remember, this was 1993 after all...).

I think his preference is for 5W-50, but he also wants a PAO/Group IV oil. Since Mobil hasn't yet brought their Euro 5W-50 to US shelves, the 15W-50 was the next best choice. I think he said he wasn't able to find Mobil 1 5W-40. He won't be running OCIs longer than 5k mi, so maybe changing his oil based on season would be best.

 

[Last_Z]

quote:

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Originally posted by BlazerLT:
I am venting here, but what is it with people using 15w oils anyways?

What is the point of it?

Does an Audi really require a 50weight oil?

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I am also venting here!

What is it with people criticizing other people about using 15W oil?