-20mm offset rims on 8 lug

[vardenafil]

i found some craigslist rims that look retro and will fit my truck. Doing research on here and other sites I found that the rims should be 0 offset. the rims i found are -20mm offset. i dont want my tires to stick out real far from the fenders. about how much will my tires stick out if i get 35x12.5 r16 tires or 35x10.5 r16 tires. if it sticks out minimal like an inch or so i will snag these rims up.

[geezer#99]

A minus 20mm is inward not outward.

[lolife99]

Originally Posted by geezer#99

A minus 20mm is inward not outward.

That is incorrect.
Negative offset wheels push the wheel out from the truck.

[Richard]

lolife99 is correct. Helpful to have more info provided. The width of the wheels? What vehicle they are being mounted on?
Assuming a 67-72 4x4 and a 10" wide wheel-
-20 is about 4.75" back space on that width of wheel. This combo would put sidewall bulge of 12.5" front tires about even with the fenders. The rears would sit a bit further in as axle is narrower.

[geezer#99]

Oops!
Sorry!

[vardenafil]

The truck is a 72 k20. Here is the listing info for the rims

Size: 16 X 8"
Back Spacing: 3.71"
Offset: -20 mm
Hub Bore: 130.81

[Richard]

Originally Posted by vardenafil

The truck is a 72 k20. Here is the listing info for the rims

Size: 16 X 8"
Back Spacing: 3.71"
Offset: -20 mm
Hub Bore: 130.81

The 12.5" tire should not be farther out than top of front fender well with those wheels. Just verify the hub bore will fit. I do not have a stock 3/4t D44 to check out.

[Dashman]

The back spacing and the offset don't correlate. If the wheel is 8" wide and the back spacing is 3.71", then there is 0.29" to the centerline. 0.29" is 7.36mm, or -7mm offset, not -20mm. The conversion is 1"/25.4mm or 25.4mm/1" depending on which units you want. Those are like factory wheels. It's the 12.5" section width that may cause some interference while turning depending on your lift. That tire will be out (12.5-8)/2 or 2.25" per side. You could actually measure out from Wheel Mounting Surface (8-3.71) +2.25 = 6.54" to get an approximate edge of tire section.

[geezer#99]

Originally Posted by Dashman

The back spacing and the offset don't correlate. If the wheel is 8" wide and the back spacing is 3.71", then there is 0.29" to the centerline. 0.29" is 7.36mm, or -7mm offset, not -20mm. The conversion is 1"/25.4mm or 25.4mm/1" depending on which units you want. Those are like factory wheels. It's the 12.5" section width that may cause some interference while turning depending on your lift. That tire will be out (12.5-8)/2 or 2.25" per side. You could actually measure out from Wheel Mounting Surface (8-3.71) +2.25 = 6.54" to get an approximate edge of tire section.

But an 8 inch wheel is measured from bead to bead. It’s actually 9 inches wide from lip to lip. Backspacing and offset are derived from the measure of wheel mounting surface to the lip.
His -20 mm is spot on.

[Dashman]

Learned something I had forgot. That's true about backspacing to the lip. However, offset is only related to the centerline because it's the same whether lip to lip or bead to bead. I agree the 3.71" backspacing does correlate to -20mm offset.

[vardenafil]

I did some quick measurements and I think the wheels will be pretty much tucked in on the rear. It might stick out like 1/2 inch or so. The fronts will stick out almost 1 1/2 inches. I found a website that shows pics of various wheel size and offset combos. It shows the k20 with an aggressive stance and the tires sticking out over 1 inch. I appreciate the help. I got to decide if I want and aggressive stance or things tucked away

[Richard]

Have owned 3 solid axle Chevy 4x4's, two 72's and an 85. Front axles all the same width. Have 17x10 wheels with 4.5" backspace for the current truck. Will run 37x12.5x17 tires. Wheels put the tread even with top of front fender. Sidewall will stick out a bit. The 8" wheels you are considering should sit about 1"-1.5" further in than mine on the front. Will be farther in on the back. Have same width axle in rear of my truck now, so front and rear reveal will be the same.