ok may not be perfect but i think it is.

so a stock 14inch wheel with stock tires are 31lbs total, or at least that is what i have been told.

i have found traklite cambers 15inch only weigh 10.4lbs
and good year assurance fuel max LRR 195/60/15 17lbs.

so a total of 27.4lbs that is 3.6lbs lighter per wheel.

195/60r15 is what tire rack says i need to go to for 15s.

3.6lbs x4=14.4lbs saving on all 4 corners.
and some say 1lbs loss of rotating mass is about 3lbs loss of static mass.
so 14.4x3=43.2lbs saving.

now i know that there is the inertia formula to account for and aerodynamics.

what you guys think

 

ok so i found a excel spread sheet calculator on rotating inertia i tried to put the the best info in it.

and this is what i got....


Wheel / Tire Weights and Rotational Inertia
Car and Wheel Dimensions: wheel 1 wheel 2
Wheel size (inches) 14 15
Tire width (mm) 185 195
aspect ratio 70 60

wheel weight (lbs) 15 10
tire weight (lbs) 16 17
Total wheel weight 31 27

Car weight (with wheel style 1) 2740
Engine Torque 93
Engine HP 116


Car 0-60mph time 11.0



I1=Rotational Inertia 1, uniform density disk 0.706 0.626

I2=Rotational Inertia 2, Tire + wheel 0.680 0.641
wheel alone 0.179 0.140
tire alone 0.501 0.501

I3=Rotational Inertia 3, Tire + wheel, edge weighted 0.906 0.855
wheel alone 0.239 0.187
tire alone 0.668 0.668

Rotational Torque G=IW Per wheel Per wheel
Uniform density disk 10.188 9.031
Tire + wheel 9.808 9.246
Tire + wheel, edge weighted 13.076 12.326
Torque devoted to linear acceleration1.052 0.916

 

so if i am reading this right less tourqe is needed to move the 15inch combo then the stock 14 inch combo.

so the only debate is aerodynamics.

 

http://t0.gstatic.com/images?q=tbn:A...fRJykhGckGO8PC

 

oh these wheels average about 120 a piece.

 

On my 2006 HCH I run G/Y Assurance F/M as well. Size 195 /65 / r15. 65 are slightly narrower tire than the 60's? H