Personally, I don't think it does. Again, the theory I heard is that each large volume of steel is of lower resistance, but they are joined by high resistance welds. Kind of like a foot of 0 gauge, joined to an inch of 18 ga, joined to another foot of 0 gauge. I never said I believed it. But I also think the difference is probably on the order of micro-ohms, and really doesn't matter. To borrow from Richard Clark, its like asking which size screen mesh to use on the door of a submarine.

I used to have a micro-ohm meter at my old shop...not sure they still have it. I'll see.

Toby