Wheel and tire weight reduction effects

[thunder550]

I am considering swapping the LTZ Tahoe 20's and 275/55R20 Toyo Proxes S/T that are currently on my half ton for a set of OE 17's with 275/60R17 Nitto 420S. The current combined weight of a single wheel and tire is around 80 lbs (about 40 each wheel and tire), maybe a couple lbs higher. The combined weight of the 17's would be about 60 lbs each (37 tire, 23 wheel).

Anyone have any estimates on the net effect of dropping 80 lbs of wheel and tire weight would have on ride, handling, acceleration, and mileage? The current ride quality is bad, mileage is meh (15 city, driving "spiritedly"), and while the truck feels quick after I get it rolling, it just feels "heavy" starting from a dead stop. I'd probably have to regear from the current 3.42 to either a 3.23 or even a 3.08 (assuming I could find a set for the 8.25" front diff) to keep the revs down at freeway speeds. Not sure if it would be worth the effort and expense, but I figure it's worth exploring.

I know unsprung weight and rotating mass play a large part in suspension dynamics, and I feel like 20 lbs per corner is a pretty big drop that might net some decent gains all around, but I have no idea how to quantify this. Any ideas or experiences?

 

[1SloLMM]

I would say it would help a lot. 3 lbs or rotational weight is equal to 1 hp gain is the general theory I`ve always been told. Especially if you drop all that weight and go to a smaller diameter setup you will definately feel a difference.

 

[rickettzusaf]

For ride quality it should improve since you will have mor of a side wall. For mileage, it will me minimal I think. You are having the same contact patch hitting the pavement so it would be the same friction contacting the ground. On the other hand though, the rotational mass should help. Its 4 pounds static weight to 1 pound rotational mass if I remember right.

Othrgrl (Dustin @ Diesel Addiction) was the one who told me about it back in 2011. Basically your 80 lbs in rotational mass you would be saving is equal to shaving off 320 lbs off the truck in dead weight.