I'm not sure what the zddp is in castrol 20w50. Any flat tappet engine like ours needs zddp @ a min of 1200-1500 ppm to keep the cams/tappets healthy...tons of stuff written on it here and elsewhere. Search here and on the pelican
http://www.lnengineering.com/oil.html
is a quick learn. They started removing zddp from oil when they found out it plugged up the catalyitic converter on cars and newer vehicles have roller cam sysytems so it's not an issue for later models.
Lots or makers make higher zddp oils for older cars but have to market them as 'race oils' to get around some regulations even tho they have the longevity packages in them that race oils do not (detergents etc).
Find out what the zddp ppm is in that oil and you'll know. I've had good results with Brad Penn, retains its viscosity even in our high Az temps where some other oils I've used have 'thinned' quickly in our summers (Kendall 20-50 titanium one time try....lasted 200 miles before oil pressures dropped 1/2 bar in hot weather, I'm no expert but assumed some loss of anti wear along with the pressure drop ). The B Penn shows the same pressure rating thru out 3-4 k miles regardless of heat.
There are more experienced Porsche guys here and hopefully they'll pipe in with their fav brand.

 

I'd stick with BP or Valvoline VR1 racing. Not sure the Castrol rates well.

 

Will switch to BP on the next oil change I honestly feel more comfortable with BP
Thanks guys..

 

Yeah you can run the castrol for a bit to clean out hour engine then dump it for a good quality oil

 

I had forgotten it was 2 cases I picked up for you, that's amazing!

 

 

Valvoline Vr1 local pickup- no shipping. Autozone/ Oreilly's etc

 

I'm still working from my haul of 80 or 90 quarts of VR-1 that I got a few years ago. I will need to re-stock this Summer because I always try to have a few cases on hand, and carry 3-4 quarts in the trunk at all times. To me, there's no sense in buying less than 3 cases at a time. That is what keeps me out of BP oil.

 

As I see it, Precise Racing's deal is a little bit better than Oil Warehouse's.

Either way, thanks! I paid $7/qt for my last change.

 

Oil Warehouse $47 a case BP

http://theoilwarehouse.com/?mainURL=...acing_Oil.html

 

Yeah if you pick it up....otherwise it's 50 bucks shipping on top of that for 2 cases.

 

Is this the one, Brad Penn 10W40 MC Oil - 009-7176?

 

I bought like 6 cases of that on the same deal-it was 2010, when I built Ruby's 3.4 motor-made all the oil changes during break-in a bit less painful.

 

Brad Penn 20W-50

http://www.penngrade1.com/Products/H...SAE-20W50.aspx

 

Hey, I just bought an 88 3.2 with 100k miles on it and the guy gave me a couple cases of this stuff. I've never heard of it, is it supposed to be any good? I see it's a semi synthetic. I thought everybody ran Mobil 1 full synthetic in their 911's.