Fuel economy vs. gear ratio/tire size

[e46inperrycounty]

Wondering what kind of fuel mileage you guys are getting with different gear sets and tire sizes. Thinking about getting some 4.56 ring and pinion sets but if the fuel economy isn't much worse for the 4.88's I might just go that route to have enough grunt to turn some even larger than currently planned tires on down the road. Thanks guys

 

[19963.4lsr5]

The 4:30's and stock 265/70's was 19 city and 23 highway.

 

[e46inperrycounty]

From what I've calculated if I change to 4.88's and run 315/75/16's I'll end up with a total ratio around 4.30~ so not too shabby. Hopefully its enough to cover the added rotational mass and whatnot. About 7mph off at 60 and 10 mph off at 80 I believe with the tire size difference.