The 195/60/15 is better. This will give you a speedometer error of 2%, so that when your speed says you are doing 60, you are actually doing 61.2
I don't think gas mileage will be affected although you will THINK so since you are traveling further than your odometer says you traveled. It says you went 60 miles in an hour but you went 61.2
Your stock tire does 850 revolutions per mile but the new tire, being slightly bigger, will do 833 revolutions per mile.