mpg with larger then stock tires

I have the original 215/70/15 tires on my 2009 base. I'd like to go a little bigger but I don't want to effect my mpg. Is anyone running 235s on their 4 cylinder 5 luggers ?

 

My Mustang wheels have 235/55/17 tires and I definitely noticed a difference over the stock 14" steelies.

Taking off from a dead stop is a little more difficult, because the overall larger diameter and greater weight have effectively reduced the final torque output. On the highway, I find myself engaging 5th gear just as often and regularly as I did before, so it's not bad at all once you're up and running. I think it's the additional energy required on the stop-and-go stuff that brings down the MPG.

With that said, overall it does hurt the fuel efficiency as well as more wear-and-tear on the clutch, but dammit, I like the way it looks and I'm willing to sacrifice practicality for aesthetics.

 

I agree you will get slightly worse fuel economy with larger tires, for several reasons that I won't get into. But if you do get larger tires, remember that you will be traveling farther than indicated on the trip meter/ODO. So be sure to make this adjustment when calculating fuel economy. The numbers might not be as bad as you think. Of course larger tires will affect the speedo accuracy as well.

 

I've got 235 75 15's on stock steelies and still manage 20 mpg when I drive the thing like I stole it lmao. At this point I don't notice the bigger tires with the deck plate and K & N; unless I'm going up north.. I find myself going into 3rd to stay at 70 on inclines, but the thing sounds mean with the exhaust ~3.5-3.8k RPM's on the climbs haha