Synthetic, Blend, or Conventional Oil?

Mr. Bills said:
Excerpts from your link:

"[Synthetic oils] are also more expensive and might be overkill for the average person driving to and from work, getting groceries and taking the kids to soccer practice and school."

". . . [A] synthetic oil can run longer oil drain intervals, in more harsh conditions than their mineral oil counterparts. . . . For some people this is an important factor, for others it might be overkill. Whatever you choose – make sure you follow your owner’s manual recommendation and match the type of oil you buy to the oil drain interval you follow." [Emphasis supplied.]

"You do not have to use synthetic oil, but there can be some real advantages to doing so. There are lots of people who use synthetic, just like there are a lot of people who do not."

The first and third excerpts acknowledge that synthetic motor oil isn't appropriate for everyone and every situation. The second demonstrates why synthetic motor oil isn't necessarily the best choice for a jeep engine.

The drain interval recommended by the Chrysler for Schedule B "severe duty" use is 3,000 miles. For light duty use the recommended service interval is 6,000 miles. If one follows BOBistheOilGuy's advice and matches the type of oil to the factory recommended service interval, the best match will not be full synthetic motor oil for most jeepers in most climates. Instead, the best type match will often be conventional motor oil for Schedule B and either conventional or a synthetic blend for Schedule A.

There are many valid reasons for choosing synthetic motor oil. A blanket statement that synthetics are "superior in every way" isn't one of them. Apparently neither is a non-specific citation to BOBistheOilGuy. However, BOBistheOilGuy does offer sound advice when he writes at the end of Motor Oil 101, Chapter 4:

"If you are looking for a good oil to use first check your owner’s manual, then make sure you pick the right viscosity grade and do not be afraid to choose something that has better cold temperature performance because that will help with better startup and reduced energy consumption. Learn about the different specifications and applications oils are designed for, then pick a brand that makes you comfortable. "
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Bill,

Thanks for taking the time to thoroughly read that article! haha

I don't use synthetic on my Jeep for the longer intervals, but for the harsh conditions and high heat I'm constantly putting my Jeep in. I change with synthetic every 3k miles (which is about once a year for me), so my oil is never broken down. In situations when my 4.0 can run very hot, I want the synthetic oil as extra insurance to the thermal breakdown that conventional experience. Also the film strength and reduced wear when i'm constantly starting and stopping my Jeep on the trails. My Jeep isn't a DD, it just get's the snot beaten out of it on the trails LOL
 
Jerry Bransford said:
What benefit do you claim synthetic oil would have given me over my 55 years of driving with nothing but conventional motor oils with absolutely never an engine issue? The only thing I ever did was change the oil and filter at appropriate intervals. And nearly all were driven well into the six figures before selling them aside from my previous TJ that was stolen ten years ago with approx 198k miles on it.

Not to mention the old ads from Volvo and Mercedes showing their engines making it to over one million miles... in the days before synthetic oils were readily available on the store shelves.

To read the opinions of some synthetic oil enthusiasts our engines don't stand a chance of making it to 50-100k miles without using a synthetic oil. :risas3:
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Jerry,

I never made the claim that conventional oil was bad or would do damage to your engine. I made the claim that synthetic oil was superior to conventional. Imagine a situation where your having a radiator leak on the trails and limping your rig out the trail with a 250F coolant temp.. Is it worth it to spend the extra couple of bucks to have the added insurance of the synthetic oil that will not break down and protect my engine better? For me it certainly is, especially considering how much money I have in my Jeep already lol
 
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rasband said:
I prefer bacon grease, but you gotta keep it warm (lest it hardens).
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I prefer 1 qt cannabis extract oil with the balance being regular old Wallyworld dino. Hundreds of thousands of miles and not one of my engines has ever been stressed out or developed cancer. Frankly they have been the easiest going vehicles to maintain you can imagine. It's expensive but is a superior procedure in every regard.
 
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Several years ago I went from 3K miles on conventional to 5k miles on synthetic (Mobil 1). Bought my TJ last summer and did the same thing. I now have a RMS leak. I'm going back to conventional next time in the TJ in hopes it slows the leak at least.
 
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Mike the Silver TJ said:
Several years ago I went from 3K miles on conventional to 5k miles on synthetic (Mobil 1). Bought my TJ last summer and did the same thing. I now have a RMS leak. I'm going back to conventional next time in the TJ in hopes it slows the leak at least.
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I’ve heard this more than a few times, it’s good to know - especially on engines with some decent mileage already clocked on conventional.
 
My TJ has less than 55K on the odometer and it appears the RMS might have been replaced already. Looks like a pretty new oil pan gasket on there.
 
Boinked said:
Mileage is only one factor on a RMS. Your TJ is also almost 15 years old. Its a rubber seal. It will break down regardless of mileage.
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My previous TJ's RMS gave up the ghost and started leaking when it had only 50-60k miles on it. Maybe even less than that.
 
Some things I have seen in my few years on this planet..
- Two collapsed orange body Fram filters (A 2.5L and 4L)

-One Orange body Fram overtightened where the body separated from the threaded mounting face where as others easily would have not. (Still human error)

All oil is fine, keep it clean with proper levels, viscosity. BUT, you may get an excellent 100-250k out of it. I have a feeling if you were on a good synthetic with the same care, you may double those numbers.

-A 4L completely disassemble with 605kms run with Mobile 1 from new. (It was very clean still with decent tolerances. Cracked head.)

I’m no expert.. and this is only one case really. Really and none bias research should easily reveal the benefits of synthetic.

We have the sum of all human knowledge... in our pocket. ;)

Cheers.
 
TrailYacht said:
Some things I have seen in my few years on this planet..
- Two collapsed orange body Fram filters (A 2.5L and 4L)
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Collapsed oil filters are usually caused by an engine problem, not a faulty oil filter. It can happen with any brand since, again, it's usually caused by an engine problem... not the oil filter itself.

https://www.machinerylubrication.com/Read/398/engine-oil-filters

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2655177

https://www.google.com/url?sa=t&sou...FjAAegQIAhAB&usg=AOvVaw3be3g8xaQltSQnBYyywP4u
 
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I purchased my 2000 TJ Sport new and have run Quaker State Synthetic 10W-30 in it ever since. It now has 215,000 miles with no leaks and doesn’t burn a drop. At about 200,000 I lost a head gasket between cylinders 3 and 4. When I pressure testing the cylinders, the other 4 were all at 150#. So I stick with synthetic these days.
 
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Mike the Silver TJ said:
Several years ago I went from 3K miles on conventional to 5k miles on synthetic (Mobil 1). Bought my TJ last summer and did the same thing. I now have a RMS leak. I'm going back to conventional next time in the TJ in hopes it slows the leak at least.
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Funny how different engines react . Mine had a RMS leak when I bought it and I use Mobile 1 high mileage and the leak has almost stopped.
 
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Twowheelz said:
Funny how different engines react . Mine had a RMS leak when I bought it and I use Mobile 1 high mileage and the leak has almost stopped.
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It is "funny" because I used the high mileage version of Mobil 1 also. Only because they did not have the standard 10w30 when I bought the oil. I dont put a lot of miles on the Jeep as I have another vehicle and like to keep the top and doors off. Probably just fine to go back to 3K mile oil changes with conventional.
 
Mike the Silver TJ said:
Probably just fine to go back to 3K mile oil changes with conventional.
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Every 3K miles is excessive for most driving situations. Jiffy Lube and the quick change shops started the whole 3k oil change interval thing... it was just another way for them to convince people they needed to change their oil more so they could make more $$$. For most of us a 5K mile oil and filter change interval is more than often enough. :)
 
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Jerry Bransford said:
Every 3K miles is excessive for most driving situations. Jiffy Lube and the quick change shops started the whole 3k oil change interval thing... it was just another way for them to convince people they needed to change their oil more so they could make more $$$. For most of us a 5K mile oil and filter change interval is more than often enough. :)
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You are probably right but I do change it myself so the $$ is not too bad.
 
Mike the Silver TJ said:
You are probably right but I do change it myself so the $$ is not too bad.
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You will find corroboration for your 3,000 mile oil change interval in your Owner's Manual and the Factory Service Manual. The "severe duty" maintenance schedule, which applies to most of us, calls for oil and filter changes at 3,000 miles and does not distinguish between conventional or synthetic motor oils. The factory recommended service interval is based upon the conditions under which the engine must operate more so than some perceived industry scheme to line the pockets of the oil companies and has been the same 3,000 mile interval since the 1950's. Still, many of us find the 3,000 mile service interval too short for the current formulations of synthetic motor oil which are touted as having extended service lives, sometimes up to 10,000 miles.

I use Valvoline "Maxlife" 10w30 and change the oil and filter at 5,000 mile intervals.
 
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Jerry Bransford said:
What benefit do you claim synthetic oil would have given me over my 55 years of driving with nothing but conventional motor oils with absolutely never an engine issue? The only thing I ever did was change the oil and filter at appropriate intervals. And nearly all were driven well into the six figures before selling them . . . . . .
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Not everyone lives in balmy California . . .
Ever done a 'cold' start-up at -20F . . . . ?
They are a harsh damaging procedure without engine heaters.
Have also got 55+ years of driving gas & diesel, and 43 years operating heavy diesel equipment.
Synthetic oil has its place.
 
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