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

[GaryR]

[Nick Triesch]

Riever, until I bought my 85 Carrera it had Castrol 20/50 all of it's life like many older 911's. My car just went 140,000 on the clock and it runs like it has 55,000. I bought it with 133,000. I started with VR-1 after I bought the car but still, I think if a car is super well taken care of with 13 QTs of oil, it will last a long long time. Nick

[RWebb]

you guys are not understanding that most of your high mileage time was run with the older oils that DID have adequate ZDDP levels !!

[Reiver]

Most oils had addequate ZDDP up until 2005. When they changed the oil ratings. I suspect the majority of your mileage was prior to that and it'll run just fine broken in. VR1 racing has the higher zddp levels but not as much detergent package as other high zddp oils.
I blew a few bump sticks on break in before I was ware of the issue some years ago. It was catastrophic totally destroying cam lobes.

[Nick Triesch]

Thank you Reiver, you and RWebb are right about my miles. But it is still strange that famous Porsche folks say that Mobil 1 is the recommended oil for our cars. You gots to wonder why! Nick

[KNS]

Because Mobil 1 has the current agreement ($$) with Porsche to use their oil in Porsche cars.

[Nick Triesch]

Sorry, Porsche and AMG and Corvette would not use an inferior oil in $100,000-$200,000 cars.

[teenerted1]

those arent flat tappet motors...thus arent applical to this discussion

[Reiver]

Originally Posted by Nick Triesch

Sorry, Porsche and AMG and Corvette would not use an inferior oil in $100,000-$200,000 cars.

I'm a Porsche newbie. Are the newer water cooled cars flat or roller tappet? If they are roller tappets then any good oil is fine.
Corvettes are rollers and Mobil 1 is not inferior oil, just not made for flat taps. Newer cars good, older cars bad.
It isn't shear or lubricity that is the issue with flat tappets (FT) it'sthe ability to withstand a strike and not dissipate. That 1mm gap set on our SC's is a 1mm non contact strike on the cam/tappet multiplied by rpm etc. Rollers absorb this thru movement, flats just get hit dead center.
The ZDDP was put in oil years ago exactly to counter this strike. It is a formula made to absorb that specific form of contact and keep oil 'in place', to cling to the strike surface.
If you've ever rebuilt a FT engine that was recently run on non ZDDP oils you can see the wear on the FT train. Pitting, hollowing of the tappets and cam lobe wear.
Call up any local engine builder and just ask them.

[brads911sc]

At the end of the day... you can buy VR1 20w50 for $5/qt or less at any FLAPS in the united states...
There are other good oils as well incl Royal Purple, Brad Penn, Redline, Kandall GT1, Swepco. The only advantage of VR1 is that its readily available just about anywhere. The others require alittle planning and do cost abit more.
With Mobil 1, you are getting less and paying more. With Castrol you are getting less and paying the same. It really doesnt make any sense to me as to why we are even having this discussion when known good oils are so easy to get.
Why take the chance when spending the same money? No one is saying you have to spend 9-10 / qt for good levels of ZDDP.

[Reiver]

Brad,
I agree.
It is just like unleaded/leaded fuel. Both are good fuels but if you use unleaded in an older motor without hardened valve seats you will get valve recession (not our Porsches, talking Iron block there ).
I think the issue here is some don't know the dif between a flat/roller tappet and why it is required to have a dif 'good' oil in older motors/valve train.

[Nick Triesch]

teenerted1, yes it is. If you read up the posts a bit you will see that in one of Harry D's posts a Porsche expert from Excellence magazine said that Mobil 1 is recommended for Porsche cars from 1984 and up. In other words, he said that you do not need the ZDDP in our older cars if you use mobil 1.

[nesslar]

Well that should keep this thread rollin'....

[teenerted1]

most Sc's&carerra's arent $100,000 porsches

[vracer]

Originally Posted by Reiver

Mobil 1 is not inferior oil, just not made for flat taps. Newer cars good, older cars bad.
It isn't shear or lubricity that is the issue with flat tappets (FT) it'sthe ability to withstand a strike and not dissipate. That 1mm gap set on our SC's is a 1mm non contact strike on the cam/tappet multiplied by rpm etc. Rollers absorb this thru movement, flats just get hit dead center.
The ZDDP was put in oil years ago exactly to counter this strike. It is a formula made to absorb that specific form of contact and keep oil 'in place', to cling to the strike surface.
If you've ever rebuilt a FT engine that was recently run on non ZDDP oils you can see the wear on the FT train. Pitting, hollowing of the tappets and cam lobe wear.
Call up any local engine builder and just ask them.

Reiver,
I've been reading various oil threads for five years. Yours is the first post (that I remember) that simplified the issue enough for my feeble brain. Thank you.

[KNS]

Excellence says to use Mobil 1. And a big source of 'Excellence' advertising revenue comes from where...? Porsche. Ever count how many ads (full page) from Porsche are in there?
Why do you think it is that you'll never read a crappy new car report from Chevy, Ford, etc in Road & Track, Motor Trend?

You don't bite the hand that feeds you.

[nesslar]

lol...only $20K, right? Wish it were so. Anyway, I'm sticking with dino and if I have to I add some stuff; I like the detergent additives to be in the oil, so I don't always go with something like ZR1 and some others....Valvoline 10W-40 maybe with a little bottle of ZDDP goods thrown in per gallon. I don't race, either, so maybe less stress makes for less chance of wear/harm anyway? No super high ambient temps around here either. Is this a reasonable approach?

[nesslar]

Originally Posted by KNS

Excellence says to use Mobil 1. And a big source of 'Excellence' advertising revenue comes from where...? Porsche. Ever count how many ads (full page) from Porsche are in there?
Why do you think it is that you'll never read a crappy new car report from Chevy, Ford, etc in Road & Track, Motor Trend?

You don't bite the hand that feeds you.

When I was a kid, I often wondered how so many of those machines could be 'car of the year'....didn't understand it at all, but I knew something was amiss.

[cnavarro]

Originally Posted by Nick Triesch

teenerted1, yes it is. If you read up the posts a bit you will see that in one of Harry D's posts a Porsche expert from Excellence magazine said that Mobil 1 is recommended for Porsche cars from 1984 and up. In other words, he said that you do not need the ZDDP in our older cars if you use mobil 1.

The need for ZDDP on older cars was incorrectly reported by the Porsche expert in Excellence, as he was just repeating Porsche doctrine. Porsche's recommended 0w40 is not acceptable. The only Mobil 1 product ok for any aircooled model in my opinion is the V-Twin 20w50 or the 4T Racing 10w40. These are excellent products.

Even the performance in water-cooled older models to current ones of Mobil 1 is just marginal - there are superior choices out there.

[Vino]

Does anyone have a UOA on Mobil 1 0w40, 5w40, 5w50 or 15w50 with at leat 3,000 miles on the oil?
Would be nice to see how the new "SN" formulation is doing in the old aircooled and to back up some peoples evidence to use it.

The new M1 0w40 suppose to have close to 1200 ppm of ZDDP and still meet the SN approval, winter oil anyone