[99metro]

I went from 155/80/13 to 175/70/13 and noticed increased rolling resistance. My coasting has decreased quite a bit. The new tires are almost one inch wider, but still the same height. There is more of a selection of tires with 175/70 than 155/80. I only got the 175/70 because some of the roads here have grooved pavement and I felt the 175/70s would keep the car from weaving like a drunk driver. For economy, I'd do the 155/80 tires and live with whatever tread design you have a choice of, if any. I've just started logging MPG here, so we'll see if I can get good MPG with these tires.