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

[brads911sc]

GT-1® High Performance Motor Oil
Typical Properties
SAE Grade 20W-50
Specific Gravity @ 60°F 0.883
Density, lbs/gal @ 60°F 7.36
Color, ASTM D1500 3.5
Flash Point (COC), °C (°F) 227 (441)
Pour Point, °C (°F) <-33 (<-27)
Viscosity, Kinematic
cSt @ 40°C 175
cSt @ 100°C 18.6
Viscosity Index 120
Cold Cranking Viscosity, cP 6,300
@ (°C) (-15)
High-Temp/High-Shear Viscosity, cP @ 150°C 4.8
Sulfated Ash, ASTM D874, wt % 0.98
Total Base Number (TBN), ASTM D2896 7.8
Phosphorus, wt % 0.108
Zinc, wt % 0.119

Charles, Can you comment? I see Zinc is basically 1190 PPM which is fine... but how does this compare to the others for Ash/ Phosphorous, etc.

This is the newest GT1 from Kendall...

Thanks
Brad

[Mark McClure]

THis thread had me both excited and confused....In Oz we do not have the range of oils available in the US so I started research. Redline is well respected here so I started with this...below is an email from Redline in answer to the question of using their motorcycle oil instead of their street engine oil....Using Redline will cost me $400aud....but with a 20K oli change it should be comparative against several $100AUD changes...

Mark!

"Hi Mark,
An unusual but not so unusual question... you might like to pass bits of this back on the forum...

In the case of the late lower-ash(lower zinc)/lower emissions oils, the emerging problem is that these oils aren't good enough for protecting older engines - especially flat-tappet camshaft engines. There is some discussion that they might not even be providing adequate protection in newer engines as rumours of wear problems are starting now that we are a good three to four years into viewing the track record - hence all the hoo-haa about oil. Porche owners therefore should be concerned - regardless of age of vehicle.

Traditionally, motorcycle oils (any brand) have more protective package (zinc, phosphorous, etc) in them simply because bike engines work harder and get a thrashing and therefore require more protection up front within the oil which also takes a thrashing. Anyone aware of this may naturally conclude that use of motorcycle oils in a Porche engine (or any motor car engine) would give more protection and on basic principal they would be correct. That's why many guys in speedway for example use motorcycle engine oils - because there is a bigger percentage of protective additives in the motorcycle oils than in some race engine oils. In discussion of Red Line Oils this is not the case as their automotive engine oils have some of the biggest packages around even more than many 'motorcycle' oils. Red Line's release of a motorcycle range last year filled a demand by the bike industry for their own labels, more so than the need to produce a higher quality oil for motorcycles, as their automotive oils could already by used in motorcycles and have been for 20 years very successfully and being wet-clutch compatible.

By all accounts, the Red Line automotive oils are already ranked as the highest level of protection you can buy determined not by marketing but by their polyol-ester basestock, the percentage of this basestock used, the percentage of additive package, and the pedigree of additive package. So the question of using Red Line's 20W60HD is not a matter of better formulation but comes back to a question of oil weights. As a general rule of thumb - whatever is recommended for an particular application with water-cooling then the same application with air-cooling is automatically a weight higher. For example, a V8 watercooled engine might call for a 10W40 engine oil but a V8 aircooled vehicle would call for a 20W50. The heavier weight oil will better withstand the higher engine temperature load that is a result of air cooling instead of water cooling. [Note at this point I should point out that oils are also ranked by their ability to transfer heat with some oils doing a far better job of assisting engine cooling than others.]

If you are living in a consistently hot climate like an Australian summer with temperatures on AVERAGE around 38°C (100°F) with an air-cooled Porche then the recommendation would still be Red Line's 20W50. Would Red Line's 20W60HD be an upgrade on their automotive 20W50? It is basically a Red Line 60W oil versus a Red Line 50W so the answer for street use is NO, when you take into consideration that Porche designed the engine to take a certain thickness oil and the issue is really about getting protection not changing oil weights. The only reason for going up in weights is when you aren't getting the protection at a lesser weight and that is nearly always fixed by using a better quality oil. Going too high can cause problems just like going a weight too low can cause problems. Red Line engine oil generally protects and outperforms a mineral oil of the next weight up anyway. With the exception of racing application where you might use the Red Line 60W Racing oil for higher temperatures and higher loads yet again and engines are generally modified anyway - there is really no consideration for using the VTwin 20W60HD oil for your particular Porche application. In the Australian conditions I refer to, the only application of the 20W60HD is for Harley bikes, but remember this is a result of hot climate + bike engine working hard + label on oil bottle says 'motorcycle' + Harleys generally like the thick oil. As you are living in a cooler average climate you could also use the Red Line 15W50 for a little more flow on cold start-up but in general don't go below the 50W for aircooled. Even the old VW use a 50W.

Hope you found some of this useful.

Regards,

Sharon Willis"

[teenerted1]

charles
some of us up here in the Pac NorWet just did a group buy on some brad penn and some guys did some test on the virgin samples and numbers dont seem up to snuff
http://forums.pelicanparts.com/pacific-northwest-us-wa-id-ut-hi-ak/463481-brad-penn-oil-group-buy-post4597197.html#post4597197

[cnavarro]

Post(s) made on other thread.

[nut11]

This thread is and has been so informative - thank you Charles. As a long time conventional Castrol guy, changing out to BP has made the difference for me. I'll tell you why: my engine runs tighter and happier - it's that simple. Can I codify the result, probably not, but perceptually, it's like an elixir. As an old fart, I'm a stone cold skeptic who has alienated more than most but this is a solid and well engineered product. On behalf of my baby, thank you.

87 blk coupe

[sp_cs]

Originally Posted by Steve W

Reader's Digest version of the last 50 pages, and after discussing this with Charles over the past couple of months, if you want the best:

For air cooled 911s:
Synthetic: Motul 300v Competition 15w50, or Mobil 1 V-Twin 20w50
Non synthetic: Brad-Penn 20w50 or Swepco 306

For water cooled 911s:
Synthetic: Motul 300v Power 5W40; 2nd choice 50/50 blend of Mobil 1 MX4T 10w40 with Mobil1 0w40(or straight MX4T)

Steve

Would the same apply to a newly rebuilt engine? I'm UK based too, ~3k since rebuild and currently using Motul 300v Power 5W40 - should I switch to the Motul 10w/40 or 15w/50?

Thanks in advance

[cnavarro]

You're fine with an Xw40 with ambient air temps up to about 90F then you probably want to switch to a Xw50 viscosity.

The Motul is the most expensive option for sure. I'm currently evaluating the performance of Motul's VW Spec 5w40 which is much cheaper (and still fully syn) in comparison to 300v. It will be a few more months, but I'm hoping this will yield a satisfactory alternative to 300v.

[sp_cs]

Thanks Charles, appreciated

[s5uewf]

Charles, do you think Brad Penn 20/50 is suitable for a 930, or are there better choices?

[GMR911]

Any one have any info on cenpeco oils? Thanks jerry

[cnavarro]

Emery, the Brad Penn 20w50 is a great oil and the most economical choice, even with shipping. That's why it's the most popular. There are tons of excellent oils to choose from, but most cost significantly more and pretty much all are mail order.

[tchanson]

Originally Posted by cnavarro

There are tons of excellent oils to choose from, but most cost significantly more and pretty much all are mail order.

I would qualify that somewhat with regard to Mobil 1 VTwin 20W50, which is readily available at my local Advance Auto Parts and AutoZone ($8.99/Qt).







Tim

[cnavarro]

Yup, can't go wrong with that recommendation either for a full synthetic.

[crater64]

Here's a little twist: Swepco 306 15W40 or BP 20W50 (syn or V-twin non-syn) okay with a Sportomatic, where the engine oil also lubricates the transmission? Charles, IIRC you did some of your testing on a 70T Sporto not unlike my own.

TIA,
Ed

[Bill Verburg]

Just a personal not, I'd like to thank Charles for his efforts on this topic, and request that he keep it up. I'd like to see how Cenpeco stacks up against the others. It looks good(according to manufacturers specs) and is available locally, makes things much easier.

[Porsche_monkey]

Ditto. Sir Charles Navarro, P.O.G. (Pelican Oil Guru).

[767driver]

Yes, a big thanks to all who have contributed here.

Now I have read most, but not all, of this and the related threads and my question is... What is the current opinion of the current formulation of Shell Rotella T? It is priced right and available at most WalMarts. My '96 Isuzu Trooper just loves it. It solved a ticking issue these trucks are known for.

The PO of my '88 Carrera took the car to a knowledgable Porsche shop for service and they used Castrol GTX 20-50. I will need to do an oil change soon and need to know about the Rotella option.

So thumbs up or down on Rotella T?

[cnavarro]

Never tried Cenpeco, but have heard of it and nothing bad, so I'd say give it a try. The best thing to do is pull an oil sample from your engine with a known mileage on it and then put in the new oil. Run it again for the same mileage and similar driving and test it again to compare whether or not the new oil is performing better or worse. This is the similar premise we worked under the last 4 years in all of our cars to test various oils. Technically, doing shorter drains, say 800-1000 miles actually will show the most difference between oils, as the majority of wear particles that are introduced to the oil are formed in the first 800 miles. There are several SAE publications that explain the process and why they do shorter intervals when doing lubricant tests in engines. The reason being is that there are many sub-species of anti-wear compounds that are formed with the introduction of heat and pressure that sometimes performs better than the raw anti-wear additives themselves.

The torque converter builds extra heat into the oil, so in my Sporto, I ran a 20w50 and even tried the BMW 10w60 synthetic oil. I don't see any reason why a motorcycle oil couldn't be used either. A choice of a synthetic should be based more so on the mileage and amount of leaks. :-)

Thanks for the kind words everyone. I haven't spent much time testing oils as of late, as I've turned my attention to testing lubricants in modern engines (like the M96), to try to find the happy medium of protection versus cost as most people aren't willing to run Motul 300V!

[cnavarro]

When the Rotella T was reformulated, I was contacted by two 356'ers that had cam/lifter & bearing failures with the new formulation, but nothing more since. It's probably marginal and still better than a true API SM rated oil. The only reason the CJ-4 spec might be marginal is that they have reduced the detergency alot compared to a CI-4 rated oil, but the Zn and P is still lower.

[alniki]

Originally Posted by cnavarro

Technically, doing shorter drains, say 800-1000 miles actually will show the most difference between oils, as the majority of wear particles that are introduced to the oil are formed in the first 800 miles.

Can this be one of the reasons to not change oil too frequently as it may actually make the engine wear more...