does the automatic locking differential add to the towing capacity of a Colorado or does just the factory installed hitch and tow/haul function add the extra capacity - is the locking differential just a nice to have- I imagine if you need the extra traction loading/ unloading, you can just pop her into 4WD - I know you need brake control over 3000 lbs trailers in most states

 

it should add zero to towing capacity.

...and 4wd vehicles have lower towing numbers due to the added weight on the 4wd parts.

a locking diff is nice to have imo. if you live in the snow belt...never get a 2wd truck.