Chrysler fwd trannys and some Fords would fail standing still. In retrospect we pulled our 22'Traillite and a 21' powerboat with a Windstar and was amazed how well it pulled it.
When minivans were first introduced they had a 3500# tow rating with a 4 banger. 20 yrs later they still rate them at 3500#. Something does not add up and I aint no engineer.
A 17' hybrid should be no problem for any V6 minivan considering you might tow 5% of the time and use vehicle as a daily driver 95% of the time.
That's why I avoided a deisel for our present rig
2008 Cardinal 30RKLE 5th wheel sold
2006 Rockwood 2607, 2001 Traillite
55 nights 2009, 53 for 2010
44 for 2011, 38 for 2012, 35 for 2013, 51 for 2014