If you are interested in towing, look at the 516/519/3500 (USA) 170 inch (4325 mm) wheel base.
I thought that the 144" wheelbase 516/519/3500 USA would be better for towing, due to the shorter wheelbase and significantly less
rear overhang.
I bought one in 2010.
The 144 3500 did tow a lot better than the 2006 158" wb 516/3500 (USA) T1N I traded in, but without the trailer on the back, the ride was very
rough and choppy due to the heavier duty rear suspension. Towing Capacity on the 2010 519/3500 144" wb was 7,500/750 lbs.
So, to gain a little more interior length (to accomdate a 14 foot Adirondak Vermont Fishing Dory with the rear doors closed) I traded that
Sprinter in on a 2011 519/3500 170" (4325 mm) Sprinter. Towing capacity 7,500 lbs./750 lbs tongue weight with the factory towing cross member
factory trailer wiring.
That one was totaled in a deer crash and the wreck traded in on an identical 2012 519/3500.
When I heard that they were coming out with the OM-651 2.143 liter I-4 inline with the 7G-Tronic 7 speed transmission in 2014 I ordered my current Sprinter with all the options and the suspension seats. Towing capacity is again 7500/750 lbs.
The overall comfort and ride quality, with the factory suspension seats is far better than any of my previous Sprinters, even unloaded
and not towing.
With the trailer (in the photo....5,120 lbs. behind a 7,500 lbs. Sprinter) I can run all day comfortably. Fuel mileage with the
trailer is in the 15-17 mpg range at 12,000 + CGVW).
Without the trailer, the fuel mileage a very consistent 23 MPG ( up from 19 mpg with the 519/3500 3.0 liter V6's and 5G-Tronic 5 speed
transmissions that required quite a bit of manual downshifting when towing.
Now with 153,000+ virtually trouble free miles the 2014 still gets 23.0 mpg when not towing 5,000 + lbs.
Roger