Questioning TRD Sport Rim Specs on the ‘Wheel Specs’ sticky….

The Wheel Specs Sticky says:

TRD Sport Alloy Wheels: 17x7.5, +30 mm offset, 5.5" backspacing, 6x5.5" bolt pattern, 108 mm hub bore


My CAD drawing:




Something is not right, it’s not possible to have a 7.5” wide rim with 5.5” backspace and 30mm offset. One of the numbers must be wrong.

Shopping for rims....

HELP! what am I not getting?

 

HAHAHA 54 views and no help!

i think i figured it out... the backspace is from the outer edge of the rim, the width must be the inside of the rim. the 5.461 dimension is very close to 5.500

the diagram way up top does not show that clearly

 

17" = diameter of the rim
7.5" = width of the rim
5.461 should not be there. the on the right is not a reference line. the distance from the mating surface to the right side of the rim(where the 7.5" value ends) should be the backspacing distance.

for orientation, the left side of the diagram is the outer side of the rim, and the right side is the inside(towards the vehicle) of the rim.

I believe the 2012 stock trd rims have a 5.5" backspacing with a 7" width