Hello group and maybe Scotty. I have a 2001 E150 with the 5.4 two valve. About 215,000 miles. Had it since 2016. Dealer purchased. Seems to have the tow package from the looks of the trans cooler and the receiver hitch in the back. A little internet research says it has a 7,000 lb towing capacity.

My concern is with the transmission. After the pre-purchase inspection, the mechanic said it had a new transmission installed recently. Well, new to it. It's never given us any problems in the last 6 years and 14,000 miles. 

The wife just bought a new camp trailer yesterday. 16 feet long and about 2,700 lbs. Have heard Scotty say to NOT use overdrive when towing or you will overheat things. There is a little button on the gear selector that lights up when you push it. The van does indeed feel like it's restrained in 3rd until you push it again. Good.

This trailer is well under the max towing capacity. For gas mileage, would it still be okay to allow it to go into 4th on level roads or is 4th now verboten whenever the trailer is back there?

btw, Would be totally cool to hear Scotty answer this on Youtube, although it would have to be shortened so his arms didn't get tired while reading it.