Is 30 weight oil still the best to run in the stock engine? If not?

Thanks

20 - 50 oils with lots of ZDDP.

Kendall GT with Liquid Titanium

Royal Purple

Valvoline VR1 Racing Oil

Brad Penn

Jake Raby's Snake Oil

and a few more I don't remember. Straight 30w would be fine if it has the ZDDP @ 1200 ppm or better, but with high temps I would prefer the multi-grade.

Chevron Delo 400 15-40, good dino oil, lots of ZDDP, a lot like what Shell Rottella T used to be.
Made for diesel, cheap, I've been using it with no issues.
It's in my T4 nickies engine, using it in several friends Type 1, /4 and /6 engines. I also use it in my Fiat tractor.
I'll be using it in my fresh 3.0 engine.

Recommended by Supertec.

Stock /6, I used to use Castrol GTX 20-50. Been using Shell Rotella T 15W-40 'Triple Protection' lately on advice from another board.

Is it not as good as it was (ZDDP?).

Here is a recent article about ZDDP.
It even talks about the changes in recipes like Jake mentions:

http://speedtalk.com/forum/viewtopic.php?f=15&t=42719

You would need to make a login acct to view, but there is some good stuff on that site.

Here is the chart of the results of how much zinc is in each:


So I think I will go with the VR1 if on a budget and the Joe Gibbs if I win the lottery.

Valvoline VR1 20W50....recommended by several engine builders for both /4 and /6 engines.

George

Whats the best source for the Valvoline VR1?

I get my 20w50 VR1 at the local Advance Auto Parts store. About $6 per qt.

George

And if my memory serves me right, it is just about the time of year that it goes on sale. So keep an eye out.
It's $5.99 a qt at advance auto, and if you order before tomorrow you can get an additional 15% off if you order online by using the online coupon (upper right corner) of webpage

http://shop.advanceautoparts.com/p/valvoli...mp;prefZC=80501

It seems NAPA in So. Cal carries this oil @ $6.39/qt.

Has something changed with the Rotella T?

Just changed my last weekend.

Also an interesting read here, how accurate it is who knows, but the manufacturers jump in and make claims w/o test data...

http://speedtalk.com/forum/viewtopic.php?f=1&t=35836

Castrol GTX is junk. I used it as my first oil post-6 conversion since it was cheap in case I needed to pull the engine back out. But did a bunch of research for my first oil change and will never touch that stuff again. Running VR-1 here as well - the ZDDP numbers are pretty solid for 20w50...Advanced has it for $6/quart which is about the same price as Mobil1 at Wal-Mart!

+1 for VR-1 20/50
On the shelf at O'Reilly

135K mi on my engine still strong with next to no oil consumption. Good stuff.

Its a 6 SOHC not a pushrod flat tappet engine. ZDDP is important on the fours not so much on the sixes. I run Mobil1 15-50.