When it was still Daimler-Chrysler and Sprinters were selling under the Dodge brand, there was a gas engine option using a M-B V-6 (M-272, M-273) built to EPA specs, shared with a number of small SUVs, C-class and E-class sedans, and some sporty coupes. The larger version made it into at least one S-class. Winnebago offered the gas option.
I wouldn't want the engine in a motorhome, though it might have been OK in an around the town Sprinter van. I think it is undersized for the application, although this is the direction RAM and Ford have been going bringing Euro vans into North America, a highly stressed V-6 offered for $6000 to $10,000 less than a turbodiesel.
