KoD. It's going back up in my area. Cheapest I saw was $1.72. It's now back to over $1.80

Never, what you will get is about 500k or more miles out the engine.

And like @KyleK said, designed for towing so you may get 15 mpg free and stick a 5th wheel on it and go to 13 where a gas engine will go from 21 free to 9 to 11 towing a load.