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

[PatrickB]

See if you can trade it for the motorcycle oil. It is the same price from where I buy it.
I spoke to the local rep, and he said that their automotive lines of synthetic have newly decreased numbers on Z&P. Without my even making mention of previously using Mobil1 VTwin, he suggested I use their motorcycle line when he learned that I was using it for an air cooled 911.

[richardlw]

If you read the paper below you will see that motorcycle oils are less slippery, so you will consume more power to move the parts. And adding additives is a crap-shoot unless you are a chemist and have $100,000 worth of equipment to see what you are mixing.

[cnavarro]

If you're referring to a motorcycle oil's wet clutch compatibility, there are ratings JASO MA and MB, which refers to how it interacts with them. You're off base generalizing that all motorcycle oils are less slippery. In fact Mobil 1 V-Twin and MX4T both have healthy levels of Moly. It has to do with whether or not an oil is friction modified, and there are many oils that don't use friction modifiers and some that use tons. Brad Penn doesn't use friction modifiers - they are in the camp of thought that friction modifiers lead to more wear. Many species of Moly are common friction modifiers used in modern oils, some of which are better at reducing friction where some are better at reducing wear. Cummins recommends against using any friction modified oils in their diesel engines because of accelerated cross-head wear, among other things.

In our dyno testing of oils, the oil's affect on engine output and fuel consumption was not as cut and dry as one would think - some lighter synthetic friction modified oils made less HP than a thicker, non-friction modified oil. On some engines, the HP differences were huge from worse to best, then on the next engine, it could be just one or two horsepower different. I think I posted a results before, but here they are: http://www.lnengineering.com/motoroiltestingwhitepaper.pdf

[JGalt]

I have been running the Shell Rotella Synthetic 5W-40 in all of my vehicles but the Porsche. (one Diesel, two gas engines) As readers to this thread are aware, this oil had the API designation "SL" and was popular with truckers, especially since Wal-Mary carried it at $15./gallon. Yesterday I picked up a couple of single quarts and noticed some of the containers had a different color scheme and now carry the API designation "SM". Can anyone tell me if this is a change in the prior formulation? I checked all of the oil for sale at Wal-Mart and all had the "SM" designation and also carried the notice "For gasoline engines".

[herman maire]

Originally Posted by cnavarro

If you're referring to a motorcycle oil's wet clutch compatibility, there are ratings JASO MA and MB, which refers to how it interacts with them. You're off base generalizing that all motorcycle oils are less slippery. In fact Mobil 1 V-Twin and MX4T both have healthy levels of Moly. It has to do with whether or not an oil is friction modified, and there are many oils that don't use friction modifiers and some that use tons. Brad Penn doesn't use friction modifiers - they are in the camp of thought that friction modifiers lead to more wear. Many species of Moly are common friction modifiers used in modern oils, some of which are better at reducing friction where some are better at reducing wear. Cummins recommends against using any friction modified oils in their diesel engines because of accelerated cross-head wear, among other things.

In our dyno testing of oils, the oil's affect on engine output and fuel consumption was not as cut and dry as one would think - some lighter synthetic friction modified oils made less HP than a thicker, non-friction modified oil. On some engines, the HP differences were huge from worse to best, then on the next engine, it could be just one or two horsepower different. I think I posted a results before, but here they are: http://www.lnengineering.com/motoroiltestingwhitepaper.pdf

Charles and Steve,

I would just like to thank you guys for all the info your passing on and research you guys are doing here for our aircooled motors but I have to say, I am loosing my marbles here thinking about which oil to run.

Not to put you on the spot but I have a 993 with the stock hydraulic valves. I just bought the Mobile MX4T 10W40 Motorbike oil ( like you guys recommend) but @ $13 quart its not cheap ( $110+tax) it hurts to buy $$$ but they do mention that it is formulated for the high temps a air cooled motor sees so that was nice to see. I know over on Rennlist there are quite a few guys with 993's and they made the switch to BradPenn 20W50, That stuff has got to be too thick for a 993's hydraulic valve set up??? I still have not heard any problems though.

I was looking at the redline website this morning and they strees that there 20W50 oil is not recommended for street use in production engines that see sustained temps below 225F. The fan on my 993 turns on a 212F and the high speed fan kicks in @235 so the oil rarely ever sees the temps the oil requires.

A few questions-

1- What oil would YOU run in a 993 with hydraulic valves? This is not for a track car.
2- Would you still buy the MX4T @$13quart?
3- Would you consider BRADPENN 10w40 motor bike oil? Its thiner than the 20W50 but it is a 100% mineral oil I think or even the semisyn 10W30?

Also, I am in the North East so it gets cool at night even in the summer.

Would really appreciate your thought on the.

[GaryR]

I am switching to the Redline (it's actually 15W50) Racing oil for my 3.0L 911 race car at the next change...

[cnavarro]

There are plenty of people running 20w50 in a hydraulic 993, so it's not a problem. That said, the basic rule of thumb I use is if ambient air temp is above 90F, then I go with 20w50. Below that, then a 5w,10w, or 15w40. I've actually been running a 50/50 blend of 0w30 Brad Penn and 20w50 Brad Penn to see how a 10w40 would perform - that's actually how they make a 10w40 when you get down to essentials. Since it's been doing really well in my 964 as far as pressure and oil consumption (i'm waiting until 2400 mi to pull a sample to compare it to the previous fill at the same miles), I just had some of the new Brad Penn Motorcycle 10w40 brought in - it's a little hard to get as it's a new product. It gets my blessing :-) but I'm going to run it at the next change to see how it compares to the current mix that is semi-syn.

The only downside to this kind of real world over-the-road testing is that it takes a while to test each oil. If I had a few people who could do this testing too in their cars back to back, it would allow us to test more oils faster.

That said, if you're happy spending the money on the 10w40 Mobil 1 MX4T, there's nothing wrong with going that route either. There's even better oils, like the Motul 300V, if you don't mind the astronomical price, but the Brad Penn is good enough and a good value.

[EarlyPorsche]

There is Shell Rotella Synthetic SL 5W-40 available at Pepboys now. If you can't get any of the fancy oils there is at least this one around for you.

[cnavarro]

Yup, not a bad choice as long as it remains the SL rated version, which is slated to be replaced by a new CJ-4/SM rated oil eventually.

[WERK I]

Originally Posted by herman maire

Charles and Steve,

.................................................I was looking at the redline website this morning and they stress that there 20W50 oil is not recommended for street use in production engines that see sustained temps below 225F.

I second the thank you.

Charles,
I have noticed these disclaimers as well. Well, it may be the case that my turbo engine may see temps "occasionally" in that range, it is more the exception than the rule. I generally run in the 190-200 degree range. What happens when you use an oil that is manufactured for this operating range?

[GaryR]

How about using their 15w50 Racing oil?

[cnavarro]

I wouldn't run the Redline racing oil in a street car - it's non-detergent and is intended to be changed about every race. The Redline motorcycle oils have the increased Zn and P and adequate detergency if Redline is your choice.

As far as viscosity versus operating temperatures and Redline recommending a thinner oil is most definately aimed at a different user base with water cooled engines - the temperatures an aircooled engine sees can very greatly and aren't as stable as in a product water cooled engine. I still stand by the old recommendation of 20w50 for ambient air temp over 90F that I have been told and seen quoted by other aircooled engine builders to their customers.

[WERK I]

Originally Posted by cnavarro

I wouldn't run the Redline racing oil in a street car - it's non-detergent and is intended to be changed about every race. The Redline motorcycle oils have the increased Zn and P and adequate detergency if Redline is your choice.

As far as viscosity versus operating temperatures and Redline recommending a thinner oil is most definately aimed at a different user base with water cooled engines - the temperatures an aircooled engine sees can very greatly and aren't as stable as in a product water cooled engine. I still stand by the old recommendation of 20w50 for ambient air temp over 90F that I have been told and seen quoted by other aircooled engine builders to their customers.

Thanks!!

[GaryR]

Originally Posted by cnavarro

I wouldn't run the Redline racing oil in a street car - it's non-detergent and is intended to be changed about every race. The Redline motorcycle oils have the increased Zn and P and adequate detergency if Redline is your choice.

I agree, this is a pure track/racing car and it's oil gets changed at a maximum of 5-6 hours of use at most.

Thanks!

[jh225]

Originally Posted by steve1rob2

For those looking for BP, The Oil Warehouse will ship cases to your door for about $4 per quart..

Oil Warehouse? Link? Phone?

[Lukesportsman]

So if we would stumble across some "old" oil on shelves, how long unopened does a traditional or syn oil's shelf life hold?

I once bought up a lot of Mobil 1 at Target old/good rating at clearance pricing of $1.28 qt. I found it quite humorous that the good stuff was on "clearance" to be replaced by the more modern downgrade.

[cnavarro]

I've been told three years is ok, but I've seen some stores around here have the same stock for even longer...

[KNS]

I once wrote Castrol asking about shelf life and they said no more than five years.

[911pcars]

Originally Posted by KNS

I once wrote Castrol asking about shelf life and they said no more than five years.

After being in the ground for a few million, what's another 5? I knew oil spills, but I didn't know oil spoils.

Sherwood

[RWebb]

Mobil told me 5 yrs for grease... so, since grease =~ oil +clay, therefore...


Shurly Sherwood knows crude oil .NE. refined oil!