How much can a truck gross weight with a 34 ft trailer?

Answer 1

Well, that's going to depend on the Gross Vehicle Weight Ratings of the power unit and of the trailer. If it was a tractor-trailer with a trailer that short, then it wouldn't be able to gross 80k - in order to do that, the bridge between the drive tandems on the power unit and the tandems on the trailer must be at least 35 feet - a length greater than the trailer you described.

You'd need some specifics about the tow vehicle and the trailer in order for this question to be answered accurately. We only know a trailer length - we don't know the GVWR of the trailer, and nothing about the tow unit, which could be anything from a Class 1 truck (0 - 6000 lbs. GVWR) up to a Class 8 truck (GVWR in excess of 33,000 lbs).