Chris D., that's a pretty impressive improvement ... almost cut your wheel & tire weight in half. When I went alloy-shopping for my car last year, I would have gotten a 1-2 pound advantage for each wheel, that's it ... hardly worth the cash involved.
I'm not surprised you noticed the truck feels more lively ... again, weight gains in the driveline are very valuable from a performance (acceleration and braking) standpoint.
Can you pinpoint any specific mileage gains ... or are you like the rest of us that eagerly make a bunch of changes and can't tell exactly which ones gave the most benefit?
