As far as performance, you won't know it's there. We tow with a gasser and have to use the rear camera to know it's there, so with a diesel you should be even better.
As far as mileage, I find it really hard to compare towing and not towing because there are too many other variables like wind direction and speed and terrain. You can't pull 3500-4000 lbs without some effect, but to me it's not significant.
Doug
Doug & Sandy
Jill (11yr old Golden)& Charmin (16 yr old something)
Henry NOW a camping cat
2008 Southwind
2009 Honda CRV
With my Cat. powered rig I really cant tell much, I dont think its over a 1/4 mile per gal. if that. A head wind or some mountainous driving is where you can notice the difference in mileage.
The CRv is a great toad, whatever the price of towing it, I wouldnt leave home without it.
Ron
2002 34HD Winnebago Journey DL, Cat. 330/freightliner
2004 Honda CRV - Garmin 1490t
Great wife & Cavalier King Charles Spaniel
TT/N
I don't see any difference in MPG towing in flat Florida. There might be some in the mountains but the DP's MPG sucks so bad in the mountains it doesn't matter/
I also have a 300 HP Cummins, but it is an older (1993) mechanical 8.3 and my coach weighs 26K loaded. We pull a Hummer, which weighs more than your CRV, but previously pulled a Mustang convertible which probably weighs about the same as a CRV. We rarely notice the toad except on steep climbs or steep down grades. Our fuel consumption is about 1/2 of a mpg between towing and not towing.
Holiday Rambler Navigator DP, Hummer, and Honda VT1100C Shadow