how much can a 2015 f150 with 5.0 engine and 3.31 gears tow

 

It all depends, see Towing info below.

 

I would add that no matter what size or weight of trailer, you need to watch your load distribution, and take time to properly set up your Weight Distributing hitch.

I've seen 3000 lb trailers that were totally unsafe, and 12,000 lbs one what were fine.

But yes, the Ford trailer guide is a good place to start.