In closing, today in class we learned that if i wanted good gas milage, i should have brought my geo metro with me when i moved out here.

 

Actually, with your commute, you're the perfect candidate for a plug-in electric vehicle.

Even a geo metro probably wouldnt warm up enough for the best gas mileage. Trus me i have a Justy i know. Best thing for short drives is a car with fuel injection.

 

Dang I would have kept the metro as a investment. Everytime gas goes up I get offered stupid silly money for the Justy.

FYI: the tire size difference is 14.5%. that sounds like a lot but it changes 13.5 mpg to 15.45 mpg. not a lot since we are talking about such small numbers.

Well it isnt that simple. It isnt so much the tire size, but there is a automotive factor called "drive wheel thrust" (basically more auto engineering term that us engineers use). With the larger tires you have effectivly changed the gear ratio of the diffs. This requires more effort to get the car moving and keep it moving. as the terrane and wind changes. At highway it should be a net gain as thats why they used to call taller gears "highway gears"