if it leaks you need to replace it anyhow.

 

I just switched jeep to Mobil 1
I run it in others cars as well. Autozone has 5qt jug an Mobil 1 filter for $32.

 

I can't remember but I know its the cheapest synthetic walmart carries. I read that it is made by Valvoline which isnt bad in my book.

 

Ok, nevermind what brand or conventional vs. synthetic, what grade are you guys running? I just put 10w30 in my XJ with 150k, was that the right choice?

 

Never need anything thicker then 5-30. My old 1990 runs on 5-30 synthetic and runs like a sewing machine. Quiet and smooth.

 

i'm using shell rotella 10w30. oil pressure is pretty good. may switch to brad penn 5w30 for the ohio winter as the bp is a synthetic blend.

 

Rotella or Delo. I believe Rotella is syn...or so they say..its truely a refined dino oil & Dello is a dino oil..and both have Zinc in them which is important for our flat tappet style cams. It also has detergants in it which will litterally clean your motor of gunk/sludge!
I've seen Rotella in 5w40, 15w40 & Delo in 15w40. I just got Delo, but plan to switch over to Rotella 5w40 for my next change! Figured it be a little easier on the old 4.0.
I always tend to grab a Bosch oil filter but got Mobil 1 this time! Guess its preference as the bosch has never let me down!
I'd also look into the big filter upgrades! Not sure if its just for Renix guys or what..but I read it up online...Went the next day & bought an adapter from the dealership for like 6 bucks..and now the filters I buy are huge compared to stock! A big filter is always a plus. Gained a steady 2psi..or almost 1 needle width after doing it as well!


I consult in the diesel world for my oil info. Those guys send in UOA's frequently and it always seems to come out to Delo 400 15w40 vs Rotella 5w40-15w40 vs Amsoil. Alot of people stopped paying a premium for Amsoil and stuck with Delo & Rotella!

Also if its your first time using Delo or Rotello then I suggest you change your oil a little early as it may be DIRTY quicker! It will clean the nasty out so it will get dirty quicker the first couple of times! For me it took 2 oil changes before the oil looked normal at 4k again!
Yes I run to 4k in between changes, but I also run a BIG oil filter. I used to run Mobil 1 and change every 3k but it was always almost black at 3k. Now Delo still has its honey color around 4k!

 

I found rotella 10w30 at walmart and advance auto parts, but thats about it. That is what i run and does pretty well. Might make the switch to brad penn as the local performance shop swears by it due to its high zinc and phosphorus content. That and both the penn and rotella aren't as thick it seems even though the weight are the same. Next time you are looking at oil, give them a shake. You can really feel the difference.

 

How long do u think it would run on peanut oil

 

I'd give it a few hours lol...4.0s are bullet proof...unless I'm missing something!
Does Bran penn have the degerants in it like the diesel oil does? Gotta look that up..haven't checked into Brad Penn.

 

I'm running Mobile one high millage 10w30 in my 89. No leaks, and she runs so smooth !

 

and as much power HAHA

just kidding

 

The engine builder there uses only brad penn. He recommended it for the older flat tappet engines as well the high performance engines of today. The 10w30 does have detergents in it. it is high in zinc and phosphorus. (1565ppm zinc, 1332ppm phosphorus).

http://www.penngrade1.com/

 

I'm sorry but I have to intervene on this old flat tappit stuff. My 1966 mustang is an older flat tappit. These jeeps cams are made from much better material. Ever seen an xj cam flatten?

 

Theres a few threads around of old fords that got the 4.2 rounding off the cam lobes. Wether its alot of alittle is does happen over time.
2 houses up a guys got a old blue ford with a 4.2 and a 3 speed. Pulls anything and he says its got like 500k on it..who knows odometer stopped just shy of 300k.

I'd perfer to just run the good stuff and know I'm helping the engine in the process...and to boot I started spending less because Mobil 1 is more expensive!