best motor oil

[SW86]

i know this has been over and over and over and i seem to recall Rotella 15w 40 as the oil of choice for our older engines??? :dunce:

[SubSonic]

I think it's a matter of choice. More importantly is actually changing it on time. I made it 300k running Pennzoil 10w-30 since the 93 XJ's birth, still ran like new, but it was changed every 5k. Then I rolled it. The end.

[comanche12]

amsoil, royal purple, redline, castrol edge, etc. are great motor oils

[jeepman 87]

Pennzoil all the way

[jimoshel]

I feel 15-40 is a bit heavy for these engines, especially in the winter. I watch the OP gauge and use a wt that will give me 5 to 10 lbs at idle and 30 to 60 at highway speeds. Oil change at 3,000 to 5,000 miles for city,dirty, severe driving, 10K for highway duty. I probably run 10-30 on a tight engine and 10-40 on a loose one. Most of the time.

[comanche12]

I feel 15-40 is a bit heavy for these engines, especially in the winter. I watch the OP gauge and use a wt that will give me 5 to 10 lbs at idle and 30 to 60 at highway speeds. Oil change at 3,000 to 5,000 miles for city,dirty, severe driving, 10K for highway duty. I probably run 10-30 on a tight engine and 10-40 on a loose one. Most of the time.

I though lower thre weight number is better for cold weather snd higher weight is better for abuse, heat,etc.[very hot outside,hauling and performance(race)] :dunno:

[SW86]

its got 10w30 pennzoil in it now but i need to change it out. i figured with the heat starting to rise a thicker oil wouldnt hurt.

[mnkyboy]

I've been running 15w/40 Delo in both my Jeeps

[flint54]

I run 5W30 in everything (I'm in Florida), and believe that as long as you meet

or exceed the API service rating specified by the manufacturer you're good to

go. Frequent change and high quality filter. I read somewhere recently that,

like gasoline, most major oils today are essentially same. I prefer Castrol, but

couldn't begin to offer a good rationale.

[cody4359]

i use to use royal purple then switched valvoline high miliage. i was at a job one day and a co-worker asked what oil i used: valvoline, he used the same stuff and his tj it began a ticking noise, then he swapped to castoral and no noise. i shortly did an oil change after that, then shortly after the oil change wanted to see how my xj would handle on the roof (see build sheet :doh: ). now i choose castoral, didnt have time to notice if it took away the ticking but that spendy oil isnt woth it seeing as a change it every 3k due to blackness and gritty. i hear good things about amsoil, and when i get my swap done I'm filling the tranny with that. on a side not ive heard that when you change oil brands it can take up to 2 or 3 oil changes for the motor to accept the new formula, true or not i dunno, but i believe it, different chems at different amounts penetrating metal with other chems in it can take a while

[mule13]

the 15w40 rotella is a diesel motor oil that contains zinc,which helps with the tapping in the low end torque engines is how it was explained to me by engine rebuild guy. when i bought the engine he gave me engine break in additive which is basically a zinc additive too. so i run the rotella.

the big thing with the inline 6's is don't use the fram filters :)

[KYMJ]

I've run Castrol for years, but recently switched to Rotella. I've noticed less ticking, maybe my imagination.

[SW86]

yup thats what i remembered about rotella, it has the zinc that our engines need. i guess ill pick some up today along with a new filter, tranny/trans case fluid and diff fluid. might as well go all out since i took that dunk through that ditch. who knows where water got into. thanks guys

 

one more ?, when changing diff fluid do you put a gasket back on or just go with RVT? ive put the gasket but i really don't want to hassle with it anymore.

[bgred2]

I have been running Valvoline High Mileage 10w-30 for the past year or two. After reading a few posts where people say their 4.0's run quieter with Rotella, I just bought a couple of gallons of Rotella T5 10w-30 at Wally World for $16.00 per gallon. Figured I would give it a try. Truck has 111,000 miles on it with no drips. Will see how it goes......... Also I use K&N oil filters.

[kro10000]

I've run mine on a diet of strictly HDEOs (Heavy duty engine oil), mostly it is whatever is around. I used to search around to try to find any oil that was API rated SJ or SL instead of the newer SM and SN because they have higher ZDDP levels. But after spending some quality time on bobistheoilguy.com the SM HDEOs have enough ZDDP levels for our old-school flat tappet engines. The oils I've been running are old Delo 400 (SJ), rotella (SM), and currently run castrol gtx diesel (SL).

And I only run a wix filter, and refuse to use any conventional oil marked pennzoil or quaker state, although pennzoil synthetics are supposed to be some of the best.

 

FWIW I have absolutely no valvetrain noise that is audible with the hood shut, and I have 215,000 miles and counting. :thumbsup:

[jeepdoggydogB]

I run Redline 10/30 and it has also reduced the valve noise considerably

[HOrnbrod]

the 15w40 rotella is a diesel motor oil that contains zinc,which helps with the tapping in the low end torque engines is how it was explained to me by engine rebuild guy. when i bought the engine he gave me engine break in additive which is basically a zinc additive too. so i run the rotella. the big thing with the inline 6's is don't use the fram filters :)

 

The zinc in motor oil is mainly to help prevent wear on our flat tappet camshaft lobes. Rotella is a good oil, but Chrevron Delo 400 Multigrade 15W40 is CI-4 diesel engine oil plus and still has 1300 ppm zinc (Rotella has only 1000 ppm). So that's what I've been using for years. :D

[dasbulliwagen]

I agree about the zinc content thing being very important for our engines, but the newer oils just don't have that in them anymore even though they say that the newer oil superceeds any of the older ones.... that just isnt true. I think the most common oil rating for late model cars is SM... it has far less zinc in it than previous oils due to manufacturers trying to keep emissions down. The higher zinc variety can either be found with diesel oils or in an SL rated oil. About the only SL rated oil Ive found is Mobil 1 High milage, and that is what Ive begun using once I found out about all this stuff. There was a huge thread on here a while back that went into great detail about all this and got me to change my mind on what I use.

[terrawombat]

I only use Castrol GTX conventional motor oil in all of my vehicles. When the local John Deere store was still in business, they'd occasionally have a good sale on Rotella oil and I would buy it in five gallon buckets, but those days are long gone.

[91coMANche]

the 15w40 rotella is a diesel motor oil that contains zinc,which helps with the tapping in the low end torque engines is how it was explained to me by engine rebuild guy. when i bought the engine he gave me engine break in additive which is basically a zinc additive too. so i run the rotella. the big thing with the inline 6's is don't use the fram filters :)

 

The zinc in motor oil is mainly to help prevent wear on our flat tappet camshaft lobes. Rotella is a good oil, but Chrevron Delo 400 Multigrade 15W40 is CI-4 diesel engine oil plus and still has 1300 ppm zinc (Rotella has only 1000 ppm). So that's what I've been using for years. :D

 

Don, I thought flat-tappet meant a non-hydraulic lifter? Is the 4.0 still considered flat-tappet like an air-cooled VW or Porsche engine? I am confused about that.

 

Where can I find the CI-4 oil? All I seem to find is CJ-4...

[05mxdiesel]

Amsoil has plenty of ci-4 oil in 15w40 and 10w30 viscosities. Also I believe Mystik still sells oil that it is ci-4.

[HOrnbrod]

Don, I thought flat-tappet meant a non-hydraulic lifter? Is the 4.0 still considered flat-tappet like an air-cooled VW or Porsche engine? I am confused about that.

 

Where can I find the CI-4 oil? All I seem to find is CJ-4...

 

I've always thought the flat tappet cams can be used with either hydraulic or solid lifters, as compared to roller cams which of course use roller lifters. But what do I know. :dunno:

 

Delo 400 Multigrade 15W40 is CI-4 plus and has 1480 ppm zinc. I get it here locally in 5-gal containers from an independent auto parts house here in town. Only place I've seen it, although I haven't really been looking for it all that hard.

[kro10000]

Don, I thought flat-tappet meant a non-hydraulic lifter? Is the 4.0 still considered flat-tappet like an air-cooled VW or Porsche engine? I am confused about that.

 

Flat and roller tappets are just the style of lifter, flat obviously have a flat friction surface that mates with the cam lobe vs a roller tip.

Flat and roller tappets can both be solid or hydraulic, which is where you are getting mixed up. Solid lifters don't self adjust and must continuously be manually adjusted, whereas hydraulic do with oil pressure, and don't need regular maintenance.

 

Since flat tappets create a shearing affect when they mate with the cam lobe (whereas rollers create far less friction) they require that ZDDP additive that creates a sacrificial bond that is destroyed instead of harm coming to the cam. Or so I've read.

 

This whole deal probably doesn't make any difference at all to the emissions or emissions equipment on a car, probably just more of a California gov't conspiracy to get all old cars off the road, just like this ethanol BS.

 

They're like in my head, man :nuts:

[Karlo]

I'm surprised there's no mention on this thread of synthetic oil, maybe it's already covered elsewhere?

 

Synthetics offer huge advantages in lubricity and wear reduction. First thing I do whenever I buy a vehicle I intend to keep is change the oil in the engine, tranny & rear end with synthetics and begin using synthetic grease as needed. Haven't had to rebuild an engine for wear since I started doing this years ago when synthetics first came out. Other than the added cost there's no downside I know of.

 

Sorry if this isn't the right thread but I'd like to know what some of you think about synthetics.

[terrawombat]

Sorry if this isn't the right thread but I'd like to know what some of you think about synthetics.

 

If I bought a brand new vehicle, I'd most likely start it out on synthetic and keep that going for the life of the engine/car. However, I only buy used heaps, normally with zero maintenance history, so I just use conventional and it has never once let me down. Oil changes happen every 3,000-4,500 miles on autos and 1,500-2,000 on motorcycles for me. I have never been able to justify the added cost of synthetic because conventional has never let me down and I've never had an engine fail because of it. There are plenty of conventional vs. synthetic engines photos out there to try and convince you that synthetic is the superior fluid, but 95% of it is marketing that's intended to sway your opinion. For my Jeeps, that don't pump out too much HP, don't rev high, and are fitted with an engine that is notorious for lasting 300K+ miles, I'll stick with conventional.