Whatever is on sale as well. However she is mainly a Florida truck, so she gets thicker oil. But the times I drove/drive up north where climate change is a thing, I’ll drain and fill with thinner. It’s cheap, and if it isn’t leaking...there is no oil

 

I used 140 and had the front differential grenade on me while on the freeway. Might be zero correlation. But it caused me to switch to Mobil 1 90 (a synthetic) and change every 20K. Overkill for sure, but maintaining these old Discos is overall so cheap compared to buying a new car... that's my rationale at least. I know we look at LR engineers with a (deserved) high degree of pessimism, but at the end of the day, my opinion is that this is the spec and it's possibly unwise to deviate from it. ¯\_(ツ)_/¯