126V8
Is your VS-30 an RV with a heavy up-fit body?
Do you plan to tow anything > 5,000 lbs. gross?
I have the 4.182 in my new VS-30 and it works great.
Now getting right around 20 mpg (very lightly loaded) @ 5200 miles on the odometer.
My older 2012/2013 OM-642's with the same engine and the 5G-Tronic Transmission used to get ~ 19 mph with the same
4.182 axle ratio so I don't see any big mileage gain with the 3.927 rear differential ratio.
Haven't towed with it yet, so time will tell if the 7G-Tronic tows as well with the OM-642 V6 as it did with the OM-651 4 cylinder.
My 2014 OM-651/7G-Tronic mostly got 22-23 mpg at a gross weight of 7,500 lbs.
The OM-642 V6 in the VS-30 certainly is tuned differently than the OM-642 with the 5G-Tronic/NAG-1.
The new OM-642 tune seems to mimic the OM-651 4 cylinder/7G-Tronic as far as shift points, but it certainly does shift more
quickly.
Hope this helps,
Roger