Wheel size Impacting MPG's Argument Help

These two guys were arguing the other day about how wheels also impact gas mileage. One claimed that a 33" tires on 16" wheels would get better gas mileage than a 33" tire on 20" wheels. The other guy was the exact opposite claiming larger rim would give better mpgs.

I thought it was just the tire size but I could be wrong.
Any help would be appreciated.

 

The only difference that I could see being a factor is the weight of the wheel and tire. Width can also make a difference in wind resistance. Even if there is a difference I can't imagine it being more than 1-2 mpg if we are talking about the same overall diameter.

Submit the senario to myth busters and see if they will test it

 

Same same unless there is a big difference in the weights when comparing the two set ups