"Conventional Protection" — they must have had their lawyers and marketing people write that. 
"Conventional Protection" — they must have had their lawyers and marketing people write that.![]()
Any 30W is going to have reduced ZDDP for the flat tappet cam due to EPA regs.
Euro 40 weights, diesel oil, or VR1 will have the most these days, but you have to actually verify the level in the diesel oil these days.
I forgot that M1 has the classic now. It is perfect for flat tappets, but it is expensive.
Mobil 1 Classic 10-w30 has ~1200ppm zddp and is formulated into it's additive package. This is probably the highest zddp content you can find today. It's full synthetic though. And $$$
The Rotella T4/T5 10-W30formulations for deisel engine have nearly as much zddp, but more calcium in them to help capture and act as detergent in an engine that produces more soot. Likely not harmful in a 4.0L but they can increase the chance of pre-detonation in gas engines under high compression.
Since you mentioned T4 10w-30, just curious: I recently bought some for my next oil change because it was on sale and I've heard people like it for the 4.0 - would you recommend I take it back?
In my '04 LJ - Previous owner had oil changed at 89500 miles at a Jeep Dealer and they used 10w30 Mopar with M-090 Mopar filter. Engine was perfectly quiet on cold start. I changed oil at 92500 with Penzoil High Mileage CONVENTIONAL 10w30 and Mopar M-090 filter. No noise after immediately starting to move out of garage, and no noise the second morning I started it. This morning - lifters tapping for about 2-3 minutes before quieting down! Anyone else have this sort of experience?
T4 appears to no longer have the gas engine ratings. No idea what they changed. BITOG probably has a VOA of it.
They would still be able to list the older gas standards it met.
15w-40 still lists SN.
