Fuel costs are highly overrated. The efficiency loss between a 25 and 30 MPG car is only 15%. Assuming the 12k/year mileage and assuming 375 miles per tank, that amounts to about 32 fill-ups annually. The less efficient vehicle would require 5 extra fill-ups, or $300 higher annual expense (15 gal tank, $4 gas price).
Quibble all you want over the assumptions, the numbers will work out to roughly $25/mo. Not that hard to find ways to recoup that *increased cost* elsewhere in life. It*s a barely a dinner for two at Chipotle, for crying out loud, haha.