asianrage

I'm looking at getting either the 5-spoke GS430 wheels or the split spoke IS250/350 wheels to replace the stock setup. Since they come in 18x8 and 45mm offset (at least for the GS430 wheels) would they fit without rubbing? I would also be using th stock 235/55/18 sizing as well. And don't want to have the wheels protrude out of the wheel well either.

Thanks guys

CK6Speed

iTrader: (1)

I'm going to have to say probably not. You may not have enough back spacing. and it may hit either the rear strut, or the inner rear fender liner.

The stock rims (If 17" are 6.5" wide with a +35mm offet). I personally ran a 20X8.5" with a +20 offset. This combo had a reduced backspacing of 10mm from stock. I cleared the strut, but marginally and I also had about a 1/4" space between the tire and rear inner fender liner.

With a 8" +45 offset rim, you will have 29mm less back spacing clearance. This may put you over the edge. Now, keep in mind this is just a static calculation. Each manufacturer may have slightly different specs for the same 8" +45 wide rim and also the size of the tire is a major factor as well. I ran oversized 255/50 tires. A traditional 245/45 tire may have enough clearance.

As for the rims sticking out past the fender you have more than enough room. The back spacing is the issue in this case.

asianrage

Thank you for the reply. Our 08 RX350 has the stock 18x7 setup which come in 35mm. So the 45mm offset of the GS430 5spoke wheel would push it into the wheel well?

CK6Speed

iTrader: (1)

Yes and no. The stock 18X7" rims are also +35mm. The rims you want are 8" +45. Since the rims are wider, they will move out by 3mm and with the +45 offset reduce back spacing by 23mm. If you measure the distance between your rim/tire and struts and inner fender liner see if you have more than 23mm to spare. If you do, the rims probably will fit.

asianrage

Ooooh okay! I'll do that tomorrow and update this thread later. Thank you.

CK6Speed

iTrader: (1)

Do a search on google for "Wheel offset calculator" and you can plug in the numbers yourself. It will show the relationship change between back spacing, offset, width, and how much further out the rims will be.

AM1

iTrader: (6)

thats really close........

asianrage

I checked and it seems that there's about 1 1/2" - 2" (38mm+) of space between the tire and the strut in the front, and barely 1" (25mm+) of space in the rear. Cutting it really close.

CK6Speed

iTrader: (1)

Yes, I forgot to be more specific and state the front has a lot more room than in the rear and you should be fine up there. The rear has the space problem.

AM1

iTrader: (6)

yea the rear wheel well is really tight....i wonder why that is. even the tire guys thought that was weird.

CK6Speed

iTrader: (1)

Since I went with oversized tires you should have seen how much space I had between the tire and spring perch in the rear. It was about 1/8"

asianrage

1/8" whoah!!! What about spacers? 5mm spacers might work, right?

AM1

iTrader: (6)

i think he was refering to the top of the tire and the bottom of the spring perch.right?

asianrage

Well, I saw that the gap between those two points weren't more than an inch apart and that's what I was goin by. The close tolerance mean that having the tires will rub against the spring perch if you go over bumps. But having spacers would probably lessen the chance?

CK6Speed

iTrader: (1)

Yes, I was talking about the gap between the tire and spring perch. Anyway, a spacer is not needed. The gap will stay static as the entire suspension along with the rim/tire will move up and down together as one unit, so that gap will never change. If it clears it will clear. A spacer will help with the inner fender liner space as well as the actual strut tube clearance though. Keep in mind though depending on the thickness of the rim hub, you may need to change our the studs to longer ones use the spacer. You may run out of tread on the studs otherwise. The rule of thumb is you need at least 6 full turns of the lug nut before you torque it down. Anything less and you need longer studs. Here is the picture below