Ok, fellas. I'm going to do this just to mess with your heads....and some of you deserve it.
Just when you thought you had CDL straight in your mind, I'll give you the short TEXAS version of how to determine CDL. Your state law may be similar.
CDL is generally based upon GVWR (disregarding certain use-related exemptions). And we all agree that the threshold is 26000-26001#. And most of us understand that in order to add a 'trailer' into that total figure, it must first exceed 10000# before it can be added.
A 'trailer' might also be a towed vehicle, so consider that if you are towing another MOTOR vehicle (as a wrecker might do, or in some other fashion) the towed motor vehicle's GVWR is then an important factor in the equation. *Remember this when you are contemplating towing another deuce with your deuce.
Now, consider the vehicle, or combination vehicle that has no identifiable GVWR (the most common of which is a home-made or shop-made trailer). Here in Texas, according to the guidance provided us by the TEXAS Administrative Rules (HA!...and you thought everything was in the Texas Transportation Code or the FMCSR's!) in the absence of a GVWR, the officer may use the vehicle's registered gross weight or actual gross weight, whichever is greater for purposes of determining CDL.
And here is a little something extra to keep you staring at the ceiling all night long. Are there times when an officer, who is not a DOT officer, is allowed to put someone who is subject to the FMCSR's out of service? The answer is YES.
Chew on that for a while, boys. Meanwhile, I'm going to bed.
Regards,
TJ