Wife and I been RV'ing since 2000, tenting before that. After an HD truck/slide in camper, then a TT, we took a break on RV'ing. By then, I had a Chevy Colorado, the 1st gen w/ the 5 cylinder engine, extended cab (not 4 door), and a 5k tow rating. One day, we looked at a small single axle Starcraft TT. Perfect! UVW was like 3500lbs (I forget exactly). Bought it, dealer hooked us up, and off we went. Just because my 4 month old Colorado had a 5k rating, did not mean it could tow a box TT.
OMG -- our first trip, all 4 of us with a loaded TT, we could barely do 45mph, and mostly did 40. Engine screaming. Weight distribution bars working OT. The truck (not just the engine) could not handle it. We swayed with sway bars. It was uncomfortable. I worried the whole weekend about the drive back home.
I swallowed my pride, opened my wallet, and bought a bigger truck. WOW what a difference to have a 1500 series truck pulling a small single axle vs. that nimble, small, fun but NOT safe to tow a TT Colorado.
To this day, I see bad towing set ups, RV related or not, and try to stay away from them. Glad I was able to admit my failure and correct it, albiet at a loss (trading a 4 month old vehicle in on a new one -- you don't come out of that smelling like a rose)...but for the safety of myself, my family, and those on the road.
Yes, the dealer hooked that small colorado up and never indicated it was a bad idea.