I personally think that if you have a lower gear ratio and beat your car on take offs, you're gonna burn more fuel than i will with my 4.10s because it takes more effort to get the car moving while mine can get there easier with the 4.10s.
We've had this debate before and people disagreed with me on that, but logic tells me otherwise. You should still make killer highway mileage though.
Your logic is...not very logical.
If there is one thing we can all agree on, it's that the higher the engine rpm, the more fuel is burned, period.
With a higher *numerical* gear ratio over stock, such as your 4.10s, you are going to burn more fuel.
Understanding this is simple.
With a higher numerical gear ratio, the rpms are higher in everything you do. When you leave from a dead stop, your engine is at a higher rpm before the car even moves. Cruising, your rpms will be higher in every gear.
More fuel is being burned over fewer miles driven. While results will vary (the amount of mileage lost), you will get fewer mpg.
"it takes more effort to get the car moving while mine can get there easier with the 4.10s. "
What does "getting there easier" have to do with maintaining or improving gas mileage? Your car "gets there easier" because the motor is at a higher rpm when it leaves from a stop, or is at an already increased rpm when you step on the throttle, so you essentially have more horsepower under your foot at any given speed because of the increases in rpm in all gears. But that increased rpm requires more fuel.
Again, fuel consumption is related to engine rpm. Just because it feels easier (quicker) to get from point a to point b, the distance from point a to point b is the same, but you are burning more fuel to get there...