What weight oil do you use?

[cnavarro]

Regardless of synthetic or not, what viscosity oil do you currently use in your Porsche? Also, what's the coldest temperature you normally start your car in?

I currently am running Mobil 1 0w40 which was that the dealer had put in, but I plan on changing to an oil with higher levels of Zn and P, yet undecided. I would easily run a 20w50 year round if it wasn't for the fact that I do drive the car in the winter and typically I have cold starts lower than 32F, but no colder than 0F.

[SCWDP911]

Charles, I posted on your other thread about oil a few minutes ago, but thought I would do th same here. I currently use Castol 20w50, but I am coming up on first oil change as the new owner on the 83 cab. I am near Memphis, TN, and we can get an occasional cold snap here that puts us in sub 32 deg temps, but very rarely below 0. Based on your post here, I am kind of curious if that is the break in temp I should be considering in cold-starts? my car is an almost daily driver.

Thanks,
Shane

[cnavarro]

20w50 is good up to 32F. A syn 20w50 technically could go even lower.

I'm holding off on making recommendations on oil for now because of the fact that so many oil companies are reformulating new SM oils, like Mobil's changing of a proven product like the 15w50. Makes you wonder what they are thinking...

I'm ordering more sampling bottles today so I can retest a few oils, just in case things have changed since I did my testing last year.

[Gunter]

Pretty relative because it really depends a lot on where you live re: temperature.
I use mostly 15W40 Dino oil because I like the specs for Diesel application (High pressure and temps)
15W40 Dino in Spring and Fall when cooler,
20W50 Dino in the hot summer months.

I would NOT recommend 20W50 when the temp is approaching the freezing point.
I like Dino over Synth. on my SC 3.0

[chuckr]

I live in Louisiana, not cold here...maybe 32 once or twice.
Really hot and humid in the summer though 100+ with 70%
humidity. I had been running Redline 20/50 I've switched to
Mobil One 20/50 and am thinking about changing to the
Mobil One V-Twin. Do you know if Mobil is changing that oil ?
I'd like to use a very good synthetic and as far as I can tell
the V-Twin Mobil One is one of if not the best.... and really
expensive !! I thought RedLine was pricey !
Chuck

[cnavarro]

No, it appears they are going to leave the Mobil 1 V-Twin 20w50 at an api SG. I will also get a bottle of the 10w40 motorcyle mobil 1 to test, but it should be about the same.

The cheapest place I have found the M1 V-Twin is at Elite Etc.

http://www.eliteetc.com/mo1v20sin.html

[Mahler9th]

Still running Mobil 1 15w-50 Extended Performance out here in CA. This is in a racing engine. A bunch of us are using it... so far no problems. I have about 60 quarts on hand in 5 qt. containers, and mt buddy has a 55 gallon drum. I guess we need to find out how much zddp it has. Charles, when is the last time you tested Mobil 1 15-50 Extended Performance? I couldn't find any dates or lot numbers on your list.

[cnavarro]

Here is a sample taken and tested 2/20 of the new SM M1 15w50 vs the levels found in the SL formulation of 1315 ppm of P and 1428 ppm of Zn.

Mobil 1 V-Twin 20w50, which is an API SG, has 1329 ppm of P and 1949 ppm of Zn.

[cnavarro]

[movin]

Charles,
Please let us know what the P and Zn levels are for Mobil1 0W-40. I use it for my other vehicles too.
Thanks for all the great info!

[movin]

Man, is there a market for restoring Zn & P levels to engine oils and it's now!
Any takers?

[glenncof]

I've run 20W50 dino (almost all GTX) for 160K miles on an '85 which is daily driver in N. Cal.

I'm looking to switch to a synth like 15W50 Pennzoil Plat. or for winter, 5W40 Rotella-T. Both appear to be based on Shell's Grp III HXVI basestock, Helix Ultra.* Of course I'm concerned about Zn/Phos (ZDP) levels and how adding boron might help. Adding GM ESO seems like a bad idea as it requires a lot (like 1qt/tank) to bring up the ZDP from 900ppm to ~1100 (Atleast according to my cals.)

Others I have considered are M1 15w50 (but Charles has bad news on the ZDP) and Castrol Syntec 20W50 (but not 5W50 as I think it's low ZDP). I did not do VOA but can cite references on Syntec.

* I have a 2005 Ford Duratec engine (porsche design) using 5W20 and recently switched from Motorcraft blend at 18K miles to Penzoil Plat. synth (HXVI basestock). I have a closed loop 40 mile highway course with MPG monitor and found astonishing 5% better gas mileage using PP synth over MC blend.

NOTE: I don't believe synth has better gas mileage for same weight so I'm skeptical. I'll evaluate 5000 mile MPG when complete OCI but on a trip to SanDiego +5% seemed to hold up. I can't explain this but could justify switch to synth if I could get +5% improvement in the 911 even if requires lighter weight.

[Paulporsche]

Mobil 1 15W50 in temps ranging from -5 to 35C (approx 24 to 95F)

[chrisp]

The thinnest possible while still maintaining proper oil pressure. Weight of oil changes with running temps which are affected by ambient temps.

[holtjv]

I was running 20/50 Valvoline with sub 30 degree starts and it was very balky and slow to start (2x). Switched to M1 15/50 EP and starts faster and on one crank.

Oh, and it's gotten warmer, too. So I have no idea how much the oil change contributed.

[88-diamondblue]

Valvoline VR-1 20-50, switching to Brad-Penn 20-50 coldest starts are 40 degrees. Driven 6 months of the year.

[diverdan]

5w/ 50 Fuchs Synthetic
Daytime temperatures often 100-120 and summer nights not below 80 F.

[cnavarro]

Originally posted by diverdan
5w/ 50 Fuchs Synthetic
Daytime temperatures often 100-120 and summer nights not below 80 F.

Where in the world do you buy that oil... never seen it before?

[movin]

Charles,
Regarding your analysis of Mobil1 15W 50 (EP), I see that Mobil has brought back the old 15W-50 (gray cap now) claiming it has the antiwear protection we're looking for. Maybe you could take a look at it.

[wachuko]

So I can switch to Mobile1 15-50 in my '83 SC 3.0??? I would love to just have to buy one oil for the cars... I already use the 15-50 on the 964.

Have not had to change the oil in the SC... but for when the time comes...