Which RV is "better" for the environment?

Which RV would be better for the environment: the Leisure Van Freedom II with the 3L V6 Mercedes Benz Diesel Engine or the same Leisure Freedom II with the Chevy 6L V8 Vortec Gas Engine? (The chassis is different (the Sprinter Cab chassis with the diesel engine, the Chevy Express Cutaway chassis with the gas engine), but other than that they’re supposedly pretty much the same RV. So which one would cause more environmental damage: diesel or gas? We already feel guilty thinking about buying an RV; can you ease any of our eco-guilt?

[b] We already feel guilty thinking about buying an RV; can you ease any of our eco-guilt?[/b] 

How about renting one only when you need it?  Do the math, I suspect you will find renting cheaper and lighter on the environment.

The diesel will, but Sprinters are known to have engine reliability problems, so you’ll be in the shop more often. Listen to Joseph. RVs are very expensive both in initial cost and in maintenance. Not to mention fuel use.

The environment doesn’t care. In fact the environment, at least everything green that grows, would like MORE CO2 in the air rather than less. So the more CO2 in the air, the faster things will grow.