I have a 2008 Mercury Mariner Hybrid. It came with BF Goodrich Long Trail Tour tires (235/70R16). They are more of a truck tire than a highway tire for a small CUV.

I had to replace all 4 wheels since they found 2 of my factory wheels were bent and caused the BFG's to get all chopped up.

I put on 4 Konig wheels and Laufenn (Hankook) X FIT HT tires. I put the same OE size wheels and tires on. On a 100 mile journey that included some highway, back roads and hill climbing I averaged 38mpg! I normally was getting 32-33mpg daily driving.


http://www.laufenn.com/en/pdf/Laufen...0HT_0930_2.pdf

 

I would have went smaller with 225 wide tires. My 2009 outlander has 225 wide tires, as do many other CUV's in the same class.

 

That's a crazy jump. Seems a little silly to purchase new tires now though I don't think you really want to live with that extra 6mpg all the way until your current tires go kaput too. If you really want to swap them back out, perhaps you can see if anyone will buy your barely used wheels off you and offset your costs?