What oil should I use for a hot climate in my 2006 TJ?

[Jerry Bransford]

While this is a true statement, the 10w-30 recommendation is more likely a bid to squeeze another 0.1 mpg for CAFE standards

It was after the CAFE standards became a thing when 5W-30 started being pushed. 10W-30 has been the usual choice since way before CAFE was a thing.