I towed our EggCamper
17' with a 2002 Sienna, then later with a 2011 Sienna. The 2002 had the 3.3L engine, the 2011 had a 3.5L engine. They both did fine, even through NH mountains. The advertised weight
of the EggCamper
was just over 2000#. I added transmission coolers to both vans and had to add air-lifts to the 2011. Although I never weighed it, my mods to the egg probably added a couple hundred pounds to the dry weight
. The 2011 Sienna had less ground clearance than the earlier 2002 Sienna.
Heads-up - I'm not sure about the 2006, but when I added the transmission cooler to the 2011, I learned that the transmission was a sealed unit and I had to return to the dealer to top off the fluid after the after-market cooler was installed. That trip cost about $100 for 1.5 pints of world-class transmission fluid. But even though, I wouldn't tow without a transmission cooler. Transmissions are much more expensive.