And just how does a car let you know that it "loves" a particular oil? Does it sit up and beg like a dog when it hears the oil cap being unscrewed? Just wondering.......

Its a figure of speech... "loves it" meaning the vehicle is running awesome. Perhaps calling the Humane Society is in order.. I see you call a Jeep a "car" ... and don't like when people refer to their cars as "she"..

Does it really matter what people state? Again.. these are figures of speech.

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I heard that the 4.0s dont like full synthetic, is that true?

It's not any dumber than people naming their cars.

No. What justification, if any, was given to back up that claim?

And....... The traditional insanity of a motor oil thread has begun yet again. 💤

I just put vegetable oil in it. Smells like french fries!

My Jeep has >258,000 miles. Been using Mobil 1 synthetic 10W-30 high mileage for the last 10 years (since probably ~150,000 miles) with K&N filters. Only real leak is from the drain-plug not sealing anymore.

I’ve used it exclusively for a decade. Still rollin'

I read that on another thread here.

Hey now. I have one that loves oil, lot's of it!

That normal, D. ; )....and btw, every time I tune back in, your signature has grown bigger!

After the abuse I put my brain and liver through in college and then the Army, it's a small wonder that my Jeep doesn't "talk" to me regularly. All jokes aside, it does seem to me that my XJ runs a bit smoother and more quietly since switching to Rotella.

Agreed. One of mine, (fine and strong at 280K), sounds better with the Castrol 30W I've run in everything for decades, then it does on sewing machine oil. It rarely freezes here and I'm the only driver, so I can get away with that. (don't try to use it sawing or drilling metal, won't cut)