With or without ECO, your mileage will drop with 35's. Plus, the 'all-terrain' never was worth much for MPG. (Great for a lot of things, but MPG ain't one of em!!!)
You may consider a gear change. ECO is not as HUGE a factor in MPG as some would like to believe. Yes, it helps, but it's not gonna get ya 10 MPG better,,, or 10 MPG worse,,,
Last edited by HoustonHemi; 12-18-2010 at 07:27 PM.