depends on the plugs..

 

Its just my opinion now but i heard a while back that Casterol SynTec Wasn't a true synthetic oil. I think I read it in one of those oil analisis things. That is what I used to run before RP. IMO it was good oil but not as good as RP. BUT... Thats my OPINION and thats all it is. Now I haven't tried the new Castrol EDGE. I have seen oil studies that say it stands up to RP in some cases.

 

I dunno. This guy told me he's seen everything and all the synthetic oils are good (except for penzoil) but his personal preference is castrol syntec which only cost me $20 for 7 qt of it. I can't find RP near where I live in NC. But I'll keep running 91+ octane in it until my next oil change and then I'll check everything. He said I won't need a fuel system cleaner and they are a ripoff anyways. My dad works for Exxon and he tells me they add so many additives to the fuel that putting premium in it a few times will clean everything with no problem.

 

Copper plugs burn better than platinum which means more power. Hemi's use copper plugs and run best on them.
Back when I ran synthetic oil in my Mustang, I would run Castrol Syntec for 10K miles. When I opened up the engine last fall @ 164K to install a bigger cam, there was no sludge at all. The engine is clean except for the normal discoloration from oil being on the surfaces.
I just run regular dino Mopar oil and filter which is changed by the dealer for $25 plus tops off my washer fluid and such. I have it changed every 3K. If your going to change it every 3K, why waste the money on synthetic oil??

 

Drain the 5w-30 tomorrow and put 5w-20 in it. The MDS needs 5w-20 to work properly.

They're not 100K plugs. Change 'em every 30-40K. Many of us use NGK 5306s, some use Bosch. Platinum is contra-indicated, as Major Burns would say.

Synthetic is your call, but not necessary. It is just a normal pushrod V-8, after all.

What constitutes "premium" in your area? If it's 91, OK. 93 isn't necessary, 89 is the minimum. If someone ran 87 for a long time, that's a problem. Clean the throttle body SOON. Easy to do, and well worth the time.

 

Oil gets dirty at the same rate, regardless of type.

 

I'll run the 5w-30 for a little while and see how my gas mileage is. If it's bad then I'll switch back to 5w-20. Premium can range from 91-93 in my area. I always fill up at Exxon which is 93. I already cleaned the throttle body. I used to run 87 in it until I found out about the plugs and oil being so dirty.

 

Unless MDS (multi displacement system) is disabled you will either screw up your engine running 5w-30 and/or void your warranty. I would swap to 5w-20 ASAP.

 

I would run 5W-20 simply because that's what the engineers who designed it recommend. And as long as I know there is no environmental lobby-istic reason why changing the weights of oils will save the world, I'll do what the manufacturer suggest on that. Same for the plugs. There's no snake oil solution for your dirty spark plugs. Just keep up suggested maintenance on it and hopefully it will help a bit. It also just may be neglected too long. Either way, I'm sure it have miles and miles more in it. If it starts making funny noises or smoking. Then you want to start saving for a rebuild at the least.

 

5W-30 IS TO THICK for when the mds kicks in it will not lube everything and then stuff will break i would change that oil yesterday to 5w 20