Tire size vs FE, Primacy MxM4/Energy Saver A/S

Debating on either switching out the wheels to 17" and set of the Energy Savers, for roughly $1300 delivered from Tire Rack, or replacing the Badyears that are currently on my car with a set of the Primacy MXM4.

Question now is, will there be much difference between the 17 and 18" wheels and these two types of tires over the LS-2?

Between the two which are better in snow?

 

Thats what I thought.

I can find cheap steel rims for the car, and mount the same size tire that is on my 2010 as a test to see if the tire size and type does make a difference, and if not, put them on my other car since it needs tires soon, but if they do work out, then I have ugly rims on it. For $15 more each rim I can get ones that look good, and if the tires dont work out, no improvement, then I can always swap them out with snow tires.

The difference in tire size is 1 MPH between the two cars.

If it does work out, the factory rims and tires will go up for sale to recover some if not all the cost.

 

I have given it a lot of thought, there is still the question, is it the tires, or the car. After what it did last night, I am on the fence on whether or not to pursue this, or cut my losses and run. I sent an email to my dealer letting him know how displeased I am with the poor MPG and now an intermittent CEL.

But you are right, even if I were to sell the OEM rims and tires, it wont make up the difference. Considering I paid extra for the 18's to begin with, not by choice, it was what was on the car, if I were to pick up a set off Flea bay, that's still over $900, I would not be able to recover that cost and the $500 or so the premium charge was. I already know Ford wont stand behind this even if I do prove its the tires/wheels.

AFAIC Ford can take the car back, I'll pay for the miles on it, but I really don't think I will ever be happy with this car, not with how difficult it is to even get 39 MPG on it. I found if I drive it lust like I do my 2010, I barely get 34. I don't know what Ford did to make it so difficult, but the 2010-12 Hybrids were so much better.