demiles wrote:
I would never tow a conventional RV TT that was 1.75x the weight of any TV vehicle. My current combination the trailer is 1.15x of the TV and it remains stable towing at 65mph in a weight carrying state no WD or sway control. A f150 HDPP weighs about 5400lbs empty, my XD weighs in at 6980lbs empty( yes a pig). Front axle weight on the f150 is about 3240lbs , my XD ihas 4200lbs on the front. So let’s add 1200lbs of tongue weight on to each truck. Based on the wheelbase and over hang the f150 front axle drops to 2800lbs, the XD will drop to 3730lbs. The higher vertical load on the tires of the heavy TV increases tire cornering stiffness(grip) both front and rear. This means it resists higher lateral forces before they slip. The COG of the heavy TV is further away from its rear axle, this alone is the biggest contribution the extra mass adds to the TV stability and it’s ability to resist sway(yaw). Of course added payload forward helps while adding it on the rear retracts on either vehicle. While using WD does increase front downforce it doesn’t move the COG back forward at all. The heavy TV can use less WD which improves handling (maintains understeer).
You can replace the XD numbers with any larger heavier 3/4 ton + vehicle and gap is greater. I don’t mean to belittle his choices but they deserve caution and wouldn’t encourage others to do the same. And by all means don’t take my word on it, do the research and find out the truth for yourselves. Please use real engineering studies and research papers available not what I or anyone else says on a internet forum. It does take time, effort, a calculator, and mathematics but the education and understanding is well worth it.
I never asked you about your towing preferences.
I'm advising you to contact the manufacturers regarding their towing guide, and try to convince them to limit their conventional towing limits to the dry weight of their vehicles.
I promise you that they will be more interested in hearing your sentiments and perspectives about conventional towing limits than I am.
