[Nasafan]

Originally Posted by Mr. Adventure

My son's Sienna and my other son's Town & Country have much softer springs than my Highlander ("softer" springs are springs that allow further motion to support the same load, and for example, are used in cars vs trucks to provide a softer ride). The obvious choices to raise the rear end: 1) tighten your WDH, 2) reduce your tongue load (carry propane in only one bottle, shift weight forward in the TV and aft in the trailer, don't carry water in the tank), or 3) stiffen the rear springs with an aftermarket product like the air bags used by an earlier poster on this thread.

The WDH works by transferring tongue weight from the rear axle of the tow vehicle forward to the front axle and back to the trailer axle. TrailManors with 15" tires, like the 3023, tend to have lots of trailer axle capacity. TM's with 14" tires, like the 2720's and 2619, tend to start out closer to their axle limits, which may limit how much you can crank up the WDH.

Formulas for towing limits are only as good as the quality of the data we have to put into them. Often the basics are surprisingly hard to come by, where the GCWR (Gross Combined Weight Rating) and the GVWR Gross Vehicle Weight Rating are in different places and sometimes difficult to find. Even then, we're still left guessing at the curb weight we're starting with for the Tow Vehicle, and we have most manufacturers telling us to subtract the tow vehicle loads from the tow rating to figure out how heavy a trailer you can tow, as if we know these exactly off the top of our heads.

The Toyota towing guide I posted earlier in this thread emphasizes attention to axle weight limits while not exceeding a specified maximum trailer weight rating. The good news is that axle weights are objective and obtainable, and the axle weight limits for the tow vehicle are on the driver's side door post. The only good way to get your axle weights is a weigh station, which isn't convenient for most of us until we're actually loaded up and on a trip. But, it's the only way to really know where you stand.

In response to Mr. Adventure, I have the WDH and an Airlift 1000 kit. I was specifically referring to the fact that even without towing, the Sienna has less ground clearance than most minivans that I have eyeballed and the Curt hitch doesn't help. My old grand caravan definitely was higher off the ground in the rear...just the way it's made.