jstyles129

Im just wondering how these would sit on the sc300 17x9 +20 in front and 17x9 +25 in the back. Let me no if you can or help me learn this offset propaganda. I havent really found a post yet that truley explains the calculations. Thanks guys.

Kohinoor

iTrader: (22)

+25 would go in the front and +20 in the rear.. and ya theyll fit with the proper tire size

kietlander

o yeah ur gonna have to roll ur rear fenders a lil bit.

jstyles129

thanks fellas but one more question how do you calculate this stuff. I dont want to come on here evrytime to ask about a rim if you know what i mean Dont want to get flamed on. If you can help please do so. thanks

plex

iTrader: (11)

I learned about SC offsets right here on CL from this thread

SC Wheel Guide

scsrock

I had problem with this too, until I found out a bit more about the meaning of each number. And my calculation is like this:

R: 17x9+20mm would be - (9-7.5)x25/2+30 = 49mm ~= 2" (outward)
and F 17x9+25mm would be 49mm - 5mm = 44m ~= 1.75" (outward)

So your wheels will be 1.75" more to the outer front fender and 2" more to the outer rear fender. (Just fixed: which is almost fine.)

Since you probably just want 1.25" out for the F and 1.75" out for the rear (which would be somewhat aggressive), you probably want something like 17x9+37mm for the F and 17x9+25mm for the rear. With 1" drop, the tires probably won't touch the fender.

scsrock

Where does that "7.5" come from? It's the width of my SC stock wheel (16x7.5+50mm). And we now probably could figure out where that "30" comes from.

<it's 50mm - 20mm>

kietlander

i big problem lies in the way wheel makers measure their offsets. u cant always go numbers... most of us learn by trial and error.

scsrock

The design of the wheels may affect the clearance for the brakes, for the same offset.

mitsuguy

iTrader: (2)

It's better to look at this as front spacing... many people use backspacing as a guide, and for trucks, this is necessary to clear suspension, but on our cars, front spacing (to tuck inside the fender) is more important...

personally, I don't like stretched tires, so I run a 275 on a 9.5" wheel... with this setup, I have +35mm offset, and rolled rear fenders with about 3mm clearance with the suspension compressed... keep in mind if you run a narrower tire, you can have a lower offset or wider wheel, so this works for people with "wide" rear tires...

so, front spacing (from hub to front side of wheel) is figured by:

width of wheel + .5" (width of wheel is inside bead seat to outside bead seat)
9.5" + .5" = 10" divide by 2 for centerline = 5" (this would be if you had a 0 offset wheel)
convert to mm, so 5x25.4 = 127mm subtract offset 127-35 = 92mm, then you can convert back to inches 92/25.4 = 3.62"

so, as a general rule, with normal suspension setups, and proper tire widths, you can run a 9.5-10.5" wheel so long as the front spacing isn't much more than 3.62" and you have rolled fenders...

jstyles129

Thanks that helped out alot I knew I could count on my club lexus homies to not only tell me if the rims would fit but also to educate me on the whole ordeal.:thumbup: thubs up to everyone

roo

agree with you all the way until the stretched tire part....now just how am I going to fit these things without stretching the tires?

bunta

just tested out my buddies wheels they are 17x8 +8 17x9 +12
the fitment is pretty decent, but 17s are kinda small for SCs, no fender roll and no pull yet will be fitting some wider wheels and dial in some camber when i tuck

champa

anyone know what's the stock wheel size/width and offset?

scsrock

My stock wheels are 16x7.5+50mm.