... of which I have plenty
I keep a pretty detailed gas mileage log on this trip - my WAG is about 14 mpg, which is close to LR4. Partly it was affected by stretches of I-80 and I-15 between Wendover and Logan, with speed limit of 80 and me driving barely faster than semis at 86.
I am sure roof rack bars don't add to gas mileage, either.
There are many minor electronic bugs with the Grenadier - like fragile Android Auto (maybe it's my phone), idiotic warnings like "high tyre pressure" when tires pumped to door-jamb-spec 49psi cold turn into 55psi at 80mph, or "low tyre pressure" when it is 10F outside, or assorted "AEB not available" or whatever. It does not affect the driving in any way, and it helps to have the instrument panel away from your face. I'd be far more concerned about assorted lights on the Classic's dash, or cryptic warnings in LR4 that mean an imminent demise but don't say so.
Hope for a software update in future.
Plenty of passing power out of that B58. Not as much as from a 5.0 in LR4, but enough.
The place we stay has a curved uphill driveway covered with ice - the Grenadier has no problems with it, just like LR4 or a rental Suburban. We remember a rental 4Runner being like a cow on ice in the same place.