Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

[jagular911]

A 40 weight straight grade has the same viscosity characteristics as an 85W gear lube. It is way too viscous to run in your engine during the winter months in LI.

Even a 20W stops pumping at 5F. If I were to drive my 911 during the winter, I would not going any heavier than a 10W. I'm not sure if you would be able to use a 10W30, or if you would need to go up to a 10W40.

There are some very bright guys on this thread-what would you recommend?

Jon

[cnavarro]

There is no need to run a straight weight - the only time I ever have a customer run a straight weight is for the break-in oil (only comes in a 30wt) and in a race car that has pre-heaters for the oil (i.e. dry sump tank heater) so the oil is already up to temp when the engine is started. With sustained extreme heat (>=300F), a mono-grade holds up a bit better, but you shouldn't be experiencing that problem.

The Brad Penn guys say their 20w50 is good down to 20F cold starts, and from my experience in my own 911, it's good down to about 10-15F, like the owner's manual states for those operating ranges.

It is not a problem switching from a synthetic to a non-synthetic or vice-versa. Sometimes going from a non-syn to a syn might result in the appearance of new leaks (which are likely old leaks that have sealed themselves).

[68redlines73]

Originally Posted by cnavarro

The CI-4 Rotella T recommended in the article does not even exist - it's been replaced by the new CJ-4 version.

I haven't looked, but the Shell web site still indicates its existence...

http://www.shell.com/home/Framework?siteId=rotella-en&FC2=/rotella-en/html/iwgen/products/zzz_lhn.html&FC3=/rotella-en/html/iwgen/products/product_rotellamulti.html

[cnavarro]

If you try ordering it through a lubricant dealer, they come back and say it's no longer sold and is superceded by the CJ-4 version. I tried this back well over a year ago, all that is left is old stock. The syn version apparently is still CI-4 or at least what I have available around here is old stock. I wouldn't count on it being available for ever either.

[TheGanzman]

Originally Posted by cnavarro

It is not a problem switching from a synthetic to a non-synthetic or vice-versa. Sometimes going from a non-syn to a syn might result in the appearance of new leaks (which are likely old leaks that have sealed themselves).

Thus my own personal dilemma. I've got a 41K mile car with ZERO oil leaks; I mean, this engine is as dry as a popcorn fart! Service history indicates Castrol GTX 20W50 at least every 3K miles since new. 4% leak-down on all cylinders from recent PPI. Upcoming oil change in less than 200 miles, Case of Brad Penn 20W50 sitting on my garage floor, and my two most trusted master Porsche mechanics (both worked for Porsche, one in Stuttgart) are BOTH telling me: "Keep running the Castrol GTX 20W50..." I waded through this entire thread, and I see cars on both sides of the "I switched to Brad Penn and it leaked/didn't leak..." fence. I'm willing to give the BP a try, just don't want it to start irrevocably leaking...

[JeremyD]

My car had pretty religious oil changes with Castrol GTX 20W50. At 56,000 miles I needed valve guides so opened up the engine. The case was stained amber colored from the castrol. The lay shaft bearings were at cooper. The cams were pitted and several of the rocker arms were out of spec. It didn't leak oil though - I guess that was nice.

[Steve@Rennsport]

Originally Posted by JeremyD

My car had pretty religious oil changes with Castrol GTX 20W50. At 56,000 miles I needed valve guides so opened up the engine. The case was stained amber colored from the castrol. The lay shaft bearings were at cooper. The cams were pitted and several of the rocker arms were out of spec. It didn't leak oil though - I guess that was nice.

That accurately describes my experiences with Castrol GTX 20w-50.

I couldn't bring myself to use it in a lawnmower,...

[mmn710]

Thanks for the helps guys. I'm def gonna switch out of straight 40. I was looking into the Brad Penn oil probobley get a case of that. I also was looking at the swepco. Which one do you think I should go for?

Also is this the BP oil.
http://cgi.ebay.com/ebaymotors/BRAD-PENN-20W-50-RACING-MOTOR-OIL-THE-GREEN-OIL-CASE_W0QQitemZ260305166386QQcmdZViewItem

[bklyn]

Try Mobil 1 15w-50 its awesome, stop with the leaks it does not happen, ifs its going to leak its going to leak!!: Dont blame the oil, it just might be your engine.

[356robo]

OK, I'm currently using Mobil V-Twin. Should I change to Brad Penn?

Rob

[PatrickB]

Originally Posted by 356robo

OK, I'm currently using Mobil V-Twin. Should I change to Brad Penn?

Rob

Perhaps you should consider reading the previous 1000 posts on this thread?
I used Mobil1 V-Twin for several oil changes. I'm now using RedLine 20w60 Motorcycle Oil with even better results. Check out Charles' web site too! He's gone above and beyond the call of duty volunteering test results of MANY different oils!

[ShakinJoe]

Originally Posted by JeremyD

My car had pretty religious oil changes with Castrol GTX 20W50. At 56,000 miles I needed valve guides so opened up the engine. The case was stained amber colored from the castrol. The lay shaft bearings were at cooper. The cams were pitted and several of the rocker arms were out of spec. It didn't leak oil though - I guess that was nice.

Jeremy

What are you using now??

[mmn710]

Why is picking the right oil so hard haha....i think I'm just gonna go with brad penn's 20W50 for the winter...I read on his site that the 40 is good for older engines and air cooled engines but might not be good to run in the winter since I'll be running it in 30 degree weather.

[JeremyD]

Originally Posted by ShakinJoe

Jeremy

What are you using now??

Brad Penn - just changed the oil this weekend - figure I would be good to my car since I've run so many track days this year.

[alniki]

Originally Posted by cnavarro

The Motul semi-syn 15w50 is next on my list to test, as it's easier to find in Europe and would make a great choice I would think. Having an ACEA A3/B3 approval is a plus for sure. Means a lot more to me than an API rating for sure. Overall, I'm very pleased with Motul's products as a whole, albeit they are very expensive in the US.

Charles,
Motul has a 300V Le Mans 20W60 that probably also warrants some test considering the Castrol TWS 10W60 you mentioned as a liquid rebuild.

[dan79brooklyn]

Here is my oil analysis from Blackstone labs.
I have been running Mobil 1 Racing 4T 10w-40 (synthetic Motorcycle oil)
The oil tested had done year, 8,000 miles, and three track days....

Any comments on the results?

I changed the oil a few weeks ago with the same product.

[Vino]

Originally Posted by dan79brooklyn

Here is my oil analysis from Blackstone labs.
I have been running Mobil 1 Racing 4T 10w-40 (synthetic Motorcycle oil)
The oil tested had done year, 8,000 miles, and three track days....

Any comments on the results?

I changed the oil a few weeks ago with the same product.

It's nice to see someone posted one of these UOA's up, it would have probably cut this thread in 1/4 the size it has become.
I would say for the mileage you went on the oil thats not too bad.

TBN looks great and generally Mobil1 seems to show higher iron.
Lead seems to be my only concern which seems a little high(bearing material?). I don't know if Porsche ever designed these engines to run 8k on a single oil change but I bet if you change it at 4 or 5K you would be fine.

Anyone want to chime in on the high Copper?

Otherwise seems like it's working great.

[WERK I]

The lead content may be from Racing Gas during the track days.............maybe?

[dan79brooklyn]

I've never run race gas...The car does use a bit of oil, I probably added 5-6 quarts during the past year/8,000 miles. I know this was a long oil change interval, but didn't Porsche reccommend very long changes even prior to synthetic oils?

[cnavarro]

Dan, that UOA looks great! Right in line with the UOAs that I have done.