Started reading up on other oil threads but everyone talks about other oils that are 40 weight. I checked a version of the A40 list and it shows Mobil1 5w-50 is the only 50 weight oil that is approved. Anyone have experience using this or the 15w-50 in their 911's and if so, what'd you think? Is this only recommended for race use? Any insight is much appreciated.

 

I ran M1 15w-50 just on the track only during summer. I wouldn’t run it on the street unless the climate allows it (summer or south United States). I wouldn’t want to run it when temps approach freezing. It never got below 50F when i ran it.

 

I want to use Mobil 1 5w. But I cant find it. I want 5 quart jugs at a decent price and ot doesn't exist. So I moved to motul a Porsche approved A40 oil.

Regarding using 5w in the winter... it is in our manuals that it is ok down to -20F.

Peace
Bruce in Philly

 

I'm considering 50 weight because I'm in Phoenix. I'm considering the 15w side because if I do one change in Spring right before the heat hits and then one in late Fall after it cools down, the oil might align well to the temperature. Do you think that works? Ever hear of someone changing liquids like that?

Yeah, I was doing some searching and it looks like I can't find 5w-50 for the 5 Gallon bulk pricing. Looks like that one is probably out as I don't think I would pay that much of a premium to run a slightly different weight Mobil1. Any advice / suggestions on running 15w-50 during the summer and 0W-40 in the winter... or potentially mixing the two to get a 7.5w-45?

 

If you have a NAPA, this stuff goes on sale for 5.29 a quart. Im changing to this shortly as frankly, I see no benefit with the boutique oils like LM/Motul/DT40. It has a better HTHS (4.3) than the typical 5w40s and has a good moly/protection package as well.

 

I run 5W-50 year around here in Colorado. Don’t drive the 911 a lot in the winter but does get out when it’s about 50 or so (more for the tires than anything). Never any issues. Car stays garaged so that helps. I would think of it would be an issue it would mainly be at start up as once the oil is up to temp the temp is the temp regardless. That said,
certainly not an oil expert - just use why my Indy recommends and they’ve never failed me.

 

Just bought a bunch from NAPA. Sale happens about 3-4 time per year. Just make sure the bottles have "FS x2" on the label. It is the newer formulation. When i picked mine up it was a mixed bag and left them with the old stuff.

They way I look at it, and my UOA seems to bear this out, I am not really using it as a 5W-50. I am using 5w-50 to end up with 5w-40 in the crankcase.

My past UOA with Mobil1 0w-40 and 5w-40 was telling me that I was shearing out of the 40 into 30 real quick. Mobil1, and sadly I think many other brands will just get it over the line to 40, sell it to us, and we shear down into 30.

No facts for the following, but I suspect that the chemical being used to move from 30 to 40 to 50 is pricier than the base stock.

Now that I have put myself out there, LET'S GET READY TO RUMBLLLLLEEEEEEE!!!!!! Why have oil thread with out a bit of brawling!!!

 

These engines like to be lubricated, the thinner the oil the easier it is to keep the oil flowing and keeping the surfaces freshly lubricated and cooled. If you are going to a 50w watch your oil temps. I would log time and temps external and engine prior to a change , then again after to see if there are any oil temperature differences.

 

You can switch to 0-40 for winter and 5-50 for summer. That makes for a clean running engine by changing the oil twice a year if you are not exceeding 10,000 miles a year. I wouldn’t mix them though.

 

I’ve been using the Mobil 5-50 with the label as recommended earlier.....I’m in Northern California, 997 stays in the garage year round and keep the garage temp at around 60 degrees generally..heated

Gut sense, if I didn’t want to waste 9 quarts of oil I’d switch it to 0-40w between December and March, I can tell it turns over slower and I’m really cautious at low outside temp in these months......you can tell it takes quite a bit longer to warm the oil to temp which don’t think is good for things........bore scoring, etc..........

 

FYI -

2010 c2s, south Florida. I've been using A40 approved Mobil1 5w-50 for last 2 years, no issues. I change it every 5K miles. Oh, and I source it from Napa.

Cheers

 

You can see all my Blackstone UOAs with Mobil 5W50 on the 991 Forum. Over 5 years worth of data points. I challenge anyone to post a UOA with lower wear metals with similar drain intervals. Outstanding results.

Do NOT use a 15W50 in a modern watercooled 911. Not good with the variocam. It's fine for the aircooled flavor.

All my UOA date here since early 2014 on the 9A1 motor, most all date from Mobil 5W50:

https://rennlist.com/forums/991/8103...-on-991-a.html

 

Thank you everyone for the feedback and the tips. Looks like it's best to avoid the 15w-50 and not to mix lubricants and go with the 5w-50.

Thanks to the tip about NAPA, I looked and have a few NAPA auto parts stores that aren't far away that sell the Mobil1 5w-50 for $5.49/qt. Not too much of a difference in cost from the 0w-40 that I get from Walmart/Costco so I'll definitely be switching. So glad I started this oil thread and it didn't turn into a spectacle that I see with other ones.

THANKS RENNLISTERS!!

 

Question: how do you warm up your car? Start and idle for awhile and then drive off, or drive off immediately? How do you bring it up to temp? What RPMs and load?

 

Start car. Hit Sport Plus button. Put on seat belt. Open the top. By then, the car has come off the high idle, and settles in at about 850 rpm, and go. I keep the RPMs under 4,000 till the oil hits 190s.