I was shopping '04 D/A Dually and noticed they come with 215/85R16 tires instead of the 265/75R16's on the 3500 SRW. I assume this is because with Duals you don't need the weight carrying capacity of the larger size tires.
However, I believe the smaller tires change the final drive ratio and shifts the optimal towing speed. My current '03 2500HD D/A towed my 13K fifth-wheel nicely at around 2000rpm which was about 62mph.
With a higher final drive ratio, 2000rpm might equate to a speed in the fifties. Does anyone know how to translate the smaller tire size into the final drive ratio and effective speed?
Bottomline, I don't intend to slow down my driving mph and I don't want to discover after the purchase that the dually has to run at a higher and less efficient RPM.
Hopefully, I'm just worrying about a non-problem and you guys can just add to my education...
Thanks in advance
2003 GMC D/A 2500HD SB 4x4, Pewter, Banks Stinger, pulling a 13K Alpenlite 5th wheel nearly full time.