Will using lighter tires and/or wheels on my vehicle increase my gas mileage? To a noticable degree?

If I choose a slightly skinnier tire and slightly lower aspect ratio but still the same rim size and the smaller tire weighs say a pound less. Is that four less cumulative pounds of spinning mass enough to increase my gas mileage by say .5 or 1 mpg? A 1mpg increase for my vehicle is roughly a $140 savings per year. So in three years I could theoretically pay for the tires just by picking a lighter tire. Any tire experts out there?Will using lighter tires and/or wheels on my vehicle increase my gas mileage? To a noticable degree?
Decreasing unsprung rotating mass is a potential area to improve a vehcile's performance, as small weight changes here can produce an affect greater than you'd think for the small weights involved. Though ultimately it is all in relation to the vehicles total weight.



Assuming what you mentioned (skinnier tires, lower total diameter, for one less pound): first the dimensions - the skinnier tires would create a smaller contact patch which would also mean less rolling resistance. This would help fuel economy, perhaps a good portion of what you are looking for. However, whatever you gain here could easily be offset by the small diameter tire, effectively lowering you overall gearing and requiring you to run more engine revs (and more fuel) to hold the same highway speeds.



Which means it all comes down to the weight difference. At one pound per tires, you would get slightly better fuel economy IF you managed to accelerate at the same rate as with the heavier tires. However, if you gave the same ammount of throttle, you would simply accerate oh-so slightly better but use the same fuel. In either case though, it wouldn't be much different. If your car has a 16 gallon gas tank, you could have a much greater net effect by never filling your gas tank past the halfway point. The weight savings of 8 gallons of fuel would be about 3 times greater than the net effect of 4 pounds of unsprung rotating mass.



Now, if you sought out ultra lightweight rims, combined with lightweight tires where you could save 5-10 pounds per corner, then you'd make a major difference... but 1 pound? Unless you are driving a go-kart or something similar in weight, you'd find almost no difference (maybe save a couple dollars/year, if that).Will using lighter tires and/or wheels on my vehicle increase my gas mileage? To a noticable degree?
No