Hi Becky,

It's certainly "possible" to tow your GMC Sierra with that motorhome, BUT you will likely exceed a couple of ratings and the gas motorhome will probably struggle on all significant upgrades.

Looking at the numbers, from the curb weight you provided, it looks like your truck has a Gross Vehicle Weight Rating (GVWR) of 6,400 lbs.  So to be within your hitch rating, you could put no more than 300 pounds (including passengers) in the truck - kind of defeats the purpose of towing a truck. 

According to your numbers on the Georgetown, you only have 1,500 lbs of cargo carrying capacity, and I'll guarantee you will use all of it and then some, especially if you don't put much in the truck.  If you load to the max of 22,000 GVWR on the motorhome, that leaves you only 4,000 lbs in your Gross Combined Weight Rating of 26,000 lbs, and the curb weight of the truck alone is 4,700 before you add anything to it.

So, if you go with this combination, I can almost guarantee you will exceed:

• GVWR on the coach (has nothing to do with the truck - I'm just sure you will carry more than 1,500 lbs) 
• GCWR of the coach
• Hitch Rating of the coach

You can always upgrade the hitch, so that would take care of the last one.  But, say you keep the truck's weight to 6,000 lbs - you wouldn't think 1,000 extra pounds would matter, but it will stress the gas engine in the mountains and it makes a big difference when trying to stop the motorhome in an emergency situation or when trying to keep speed down on steep or long downgrades.  Even an 1,800 lb Smart Car has a surprising effect on diesel pushers.

Simply, put this Georgetown isn't designed to tow something as heavy as your truck.  People tow more than their motorhomes are designed to handle all the time, especially those with gas motorhomes and Class Cs, but that doesn't necessarily mean it's the safest thing to do.  Those ratings are all there for a reason.

Oh, by the way, towing four wheels down doesn't add any weight to the motorhome, nor does it affect your "tongue weight" rating.  It's the best option for full-timers and frequent RV travelers.

I'm not trying to burst your bubble.  That Georgetown looks like a great unit, and we certainly understand wanting to tow a vehicle you already own.  I personally wouldn't go with that combination for a full-timing lifestyle (motorhome doesn't have enough cargo carrying capacity and it's not designed to tow that heavy of a vehicle), but if you do, just be very cautious and you will probably want to unhitch the truck for mountain passes (both up and down).

We look forward to seeing you next Spring!