With all the talk about fuel economy on here I was curious what everyone thinks the difference in mileage would be between stock tires and bigger tires. I have a set of 305/70's on that have been on there since right after I bought the truck. My dad has told me about a set of new stock wheels and tires that can be had for $400. I don't mind changing them but do you think I would see significanty increased mileage on long road trips? Just a thought. I love the tires I have and need them for the off-roading and towing into the sand that I do. My truck is a 2500 HD all stock except for tires.

I think you'll get alot more posts about your questions in the wheels and tires section, I'll go ahead and move this over there :)

With all the talk about fuel economy on here I was curious what everyone thinks the difference in mileage would be between stock tires and bigger tires. I have a set of 305/70's on that have been on there since right after I bought the truck. My dad has told me about a set of new stock wheels and tires that can be had for $400. I don't mind changing them but do you think I would see significanty increased mileage on long road trips? Just a thought. I love the tires I have and need them for the off-roading and towing into the sand that I do. My truck is a 2500 HD all stock except for tires.

I had the same question. Look at Dutchpilot's post here: http://dieselplace.com/forum/showthread.php?t=229134&page=20

If you need the 305's for sand running, then putting a smaller tire might not be the best choice. The stock size tires will give you better mileage than the 305's on normal highway driving. They are much thinner and have far less drag on the road, as well as they are more aerodynamic and don't grab so much air. The last thing, they are much lighter and therefore have less paracytic drag.

I guess the decision is how much sand do you drive on vs normal driving. That might make a difference.