klr650goldwing wrote:
Is there a general rule regarding how much weight is okay for SRW and how much is too much? We are thinking of a larger 5er and not sure how much larger will require a new truck too.
The rule is GVWR. You can pull more than you can carry. Once you run out of payload, that's it. Even if you could, in theory, pull more, once any one rating is busted, you're done.
Older trucks had far less payload than the newer ones. You'll find some SRW trucks with GVWRs over 11,000 pounds, where they were closer to 9k 20 years ago and 10k 10 years ago. DRWs are closer to 14k pounds, whereas they were 10k 20 years ago and 12k 10 years ago. The trucks of today are themselves a little heavier, but most of the increased GVWR has become increased payload capacity.
Just to give you some numbers about my truck so you can see how I do the calculation:
Truck unloaded vehicle weight (UVW): 7,200 (this is full of fuel, no passengers)
Truck GVWR: 9,900
Payload capcity: 9,900-7,200 = 2,700 pounds.
Trailer UVW 9,200
Trailer GVWR 13,500
Trailer pin weight empty: ~2,180
GWWR - UVW - pin weight = 520 pounds of remaining payload for me, my dog, and whoever else is in the cab.
Which shows I'm a little tight on weight for passengers and gear. Fortunately it's usually just me and the dog, with enough payload left over for a passenger. All of our gear goes in the trailer to keep us within GVWR.
DRW truck of the same year would give me another 2k pounds of GVWR. Certainly that would greatly increase the total combination weight I could have on board.
Just so you have an idea, GCWR is 23,500 for my truck. Total weight the last time I went over the scales was 16,500. That means in theory the drivetrain can pull another 7,000 pounds. Realistically, there's no way to load the truck and trailer in such a way to make that possible. While I could probably put something pretty heavy in the back of my toyhauler and have similar pin weight, I highly doubt I could get to another 7k pounds without overloading the GVWR. And in any event, My trailer's GVWR would be busted before that happened; it has 6k lb axles.
Hope this real world example helps.