Any oil that meets the OEM specs should perform well given routine oil changes. The Synthetic oil change frequency is a little longer than conventional oils but you pay more for the synthetic oils. I personally run Mobil 1 in all my vehicles with a 7k oil change frequency, but have run Dino oil at 4K oil change frequency successfully for a long time as well.
I would choose synthetic oil in the jeeps for trail use due to lower rpms, extended idling, and higher engine temps. The synthetic oils will out perform Dino oils - more resistance to thermal breakdown.
The real question is what oil filter are you using? Don’t go cheap on them, ever! Look at the efficiency ratings, as you want one >99%. Pay the extra few $ for a high efficiency filter.
Also keep your air filter changed with a quality filter. A dirty air filter will cause elevated oil particulate counts and with a shitty oil filter results in accelerated engine wear (bearings, rings, cylinder walls, rockers, etc.).
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