Been recommended to use 20W-60 oil in my TJ
- Thread starter Fishtaco
- Start date
Matches perfect to your tire recommendations on the manufactures sicker12" lift.Be careful taking free internet advice. It usually comes with a price.
Why ask a forum full of "laymen" about different oil recommendations if you're just going to get pissy and tell us that your mechanic questions much of what we're recommending? I don't know about you're manual, but mine NEVER recommends anything heavier than 10W-30. And that recommendation comes from those idiot engineers that understand all the math and rocket surgery that goes into making that call. If your engine runs at 210 in hot weather, and you maintain good oil pressure, why beg for problems?
You solicited opinions, without asking only for experts, from a large group of random strangers and you expected exactly what? Is this your first day using the internet?
Expert "Bob is the oil guy" says 10w30 or 5w30. Case closed.
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Also, 100k miles is not that high of a milage for a 4.0. I just drove around death valley in 108+(42c+) temps with AC, over 200k miles and 10w30 oil. Also, why mineral oil?
The engine was designed for 10w30 bog standard oil. Go with that.
The engine was designed for 10w30 bog standard oil. Go with that.
well, I didn't need to get a mechanical engineering degree to know what viscosity is, but if it helps convince you, I have one. I even did a lab assignment in school where we took several different viscosity grades of automotive engine oil and actually measured their viscosities at several temperatures to understand things like what makes 10w30 different from SAE 30, etc. I've slept too many times to recall many of the finer details, but the viscosity measurement basically consisted of timing how long it took a given volume of oil to run through a calibrated orifice.
Since then my experience has been in the commercial/industrial HVAC industry, but guess what that involves? Compressors. Which are in many ways a lot like engines. And they require lubrication. With oil. And they can be kinda picky about viscosity.
Your comment about upping the viscosity rating from 40 to 60 because of the zinc content makes no sense because zinc content and viscosity are two completely different things. Zinc is one of many ways to improve wear resistance at high pressures, such as the cam-lifter interface. Viscosity is a fluids resistance to flow. You want a viscosity low enough for your pump to be able to move it but high enough that it doesn't run right out of your main and rod bearings faster than the pump can get it there. There seems to be a design philosophy common in Europe that results in recommendations of higher viscosity grades like 20W50. I don't know whether the difference lies in oil pump design, volume flow demands, bearing clearances, or all of the above, but despite being an inline 6 and briefly being owned by Daimler, the Jeep 4.0 isn't the exact same thing as a BMW and it shouldn't be assumed that they have anything in common beyond their cylinder orientation.
I am not getting pissy? I was replying at 4.30am on Saturday morning before a 5am leave for work!
I think some of the comments were non constructive and speculative given my oil recommendations were given by experienced professionals who have nothing to gain from it as I do my own intermediate oil changes.
4 mechanics at work over a 45 min discussion on Friday afternoon, my local USA 4x4 mechanical repairs shop and my regular service garage for daily drivers who has 3 generations of racing background all recommended the same or similar oil for my next change?
What I was looking for here I suppose was TJ specific experience in "using heavier weight oil " in a hot climate so its my fault for not reiterating such.
My real question should have been who has used heavier weight oil in a 4.0 with no adverse effects? I dont want to fuck my engine because its "Mine" and the sole reason I am asking!
Before my first oil change I went straight to 10w 30 at a great expense and immediately started to get a cold start up rattle, this is indicative of engine wear yes I know this is fact but I am not yet ready to spend $10,000 au on a rebuild if I dont need to.
I think some of the comments were non constructive and speculative given my oil recommendations were given by experienced professionals who have nothing to gain from it as I do my own intermediate oil changes.
4 mechanics at work over a 45 min discussion on Friday afternoon, my local USA 4x4 mechanical repairs shop and my regular service garage for daily drivers who has 3 generations of racing background all recommended the same or similar oil for my next change?
What I was looking for here I suppose was TJ specific experience in "using heavier weight oil " in a hot climate so its my fault for not reiterating such.
My real question should have been who has used heavier weight oil in a 4.0 with no adverse effects? I dont want to fuck my engine because its "Mine" and the sole reason I am asking!
Before my first oil change I went straight to 10w 30 at a great expense and immediately started to get a cold start up rattle, this is indicative of engine wear yes I know this is fact but I am not yet ready to spend $10,000 au on a rebuild if I dont need to.
I have expert advise but why not ask for "at source" TJ driver operator specific experience? Is that not what this forum is about?
100k mileage in Australia is almost ready for the junk yard and if memory serves me correct? many on this forum recommend a high mileage mineral oil in a high mileage TJ?
You need to put those 235/75/16s back on that Rubi and come back down to earth! lol
Saturday night and the PBR is kicking in lol
Its like Jekale and Hyde! I only posts in the wee am or after 7 pm beer time!
Its like Jekale and Hyde! I only posts in the wee am or after 7 pm beer time!
I worked with an Engineer in 1977 who had an old personal vehicle, he only ever used the crank handle to start it to save crank amps so his heater worked on a fucked battery
I am old I used to hand crank diesel machinery on site every day! lolWhat do I Know? I am a Civil engineer! If I was a mechanical engineer my response would be your advise on oil viscosity given is incorrect! or is it? Wait I will just consult my guys on the ground as my lecturers had zero real time experience to explain this! lol
I was stationed at ET A school in the Navy at Treasure Island in 1970 when Admiral Zumwalt decided we could have beer in the soda machines. They were filled with PBR, a quarter for a can. Yes, drunk, for $2!
Zumwalt and his Z-Grams, he was great. I wasn't even Navy but knew he was one of the standout Navy Admirals.
I live in the tropics, hot weather all year round and would not even consider running 60w oil. That weight is just to thick, I've seen 40w with high mileage engine, but at 60w it might not even lubricate the engine propperly. In an earlier post you mentioned that 100K is when most cars will go to the junkyard. It is a known fact that the tj can make it to 200-300k. If they are all using 60w oil for the Tj's there might be some correlation to the time the engine blows and the kind of oil you are using over there.
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