38" Offset

sbuscha · #1 (**permalink**) 05-23-06, 06:08 PM

I am getting 18” x 245 x 45 with a 38" offset. The rim is 18 X 7.5.

Is this offset okay for our cars?

RobertCTS · #2 (**permalink**) 05-23-06, 06:34 PM

Wow, close call. 40mm is the target. 38mm is close. Ody is the resident expert on offsets. I'm sure he will see your thread. Got a pic of them you care to share?

sbuscha · #3 (**permalink**) 05-23-06, 07:02 PM

They are Milanni Ambrosia wheels. How can I add a pic?

Her is a link to the wheel. It is at the bottom. http://www.tiresdelivered.com/search...FSET=HIGH&pg=2

RobertCTS · #4 (**permalink**) 05-23-06, 07:07 PM

Quote:

Originally Posted by sbuscha

They are Milanni Ambrosia wheels. How can I add a pic?

Her is a link to the wheel. It is at the bottom. http://www.tiresdelivered.com/search...FSET=HIGH&pg=2

You scared the heck out of me. The first wheel that came up looked like it was designed for a Bradley tank! Here's a better link of the wheel I think you want. Nice lookin'. We need for Ody to approve that 38mm offset. I think your tire size will have some impact too. You have enough post to PM Odysseus (Ody)

B Hoth · #5 (**permalink**) 05-24-06, 01:01 AM

Try photo chopping it to your ride. Definitley a different look and the tires will look huge with the lip on those. Different is good!

odysseus · #6 (**permalink**) 05-24-06, 06:50 AM

2mm isn't much difference. I doubt it will be noticeable. If anything it may rub slightly on the upper center part of the fenderwell when the rear is loaded with weight, but the risk is minimal.

245's on a 7.5" wide wheel will give you some sidewall bulge and some sidewall 'rolling' in the turns. The tires will also tend to wear in the middle. To visualize this, look at your stock wheel, and add almost another half inch (10mm) to the tire hanging over of the side (both inside and outside). I always recommend 8" or 8.5" wheels for 245's. Most (if not all) tire shops will recommend 225's for a 7.5" wide wheel, but you can typically mount 235's on them without a lot of worry. 235's on a 38mm offset will also guarantee that you'll have no rubbing.

Personally, I'd find 8" wheels if you want to go 245's. Stick with 235's if you really are in love with that wheel, and can't find a bigger size. But that's just my opinion, of course.

RobertCTS · #7 (**permalink**) 05-24-06, 07:38 AM

I agree with Ody. I compromised with my set up. I loved the rims and 7.5 was all that was available in 18". So I got them anyway. My second mistake(yes I even share my mistakes) was to mount 245x45x18 Pirellis on them. I should have used 235x45x18".

Between www.victoriatire.com and www.thetirerack.com you have a huge selection to choose from.

MemberX · #8 (**permalink**) 05-24-06, 08:38 AM

I have 7.5 rims with 45mm offset.

tires are 18/235/45.

RobertCTS · #9 (**permalink**) 05-24-06, 08:54 AM

Quote:

Originally Posted by MemberX

I have 7.5 rims with 45mm offset.

tires are 18/235/45.

Is that the CTS Sport 18" wheels? It's a good looking wheel!

pmpott · #10 (**permalink**) 05-24-06, 09:00 AM

Quote:

Originally Posted by Odysseus

2mm isn't much difference. I doubt it will be noticeable. If anything it may rub slightly on the upper center part of the fenderwell when the rear is loaded with weight, but the risk is minimal.

245's on a 7.5" wide wheel will give you some sidewall bulge and some sidewall 'rolling' in the turns. The tires will also tend to wear in the middle. To visualize this, look at your stock wheel, and add almost another half inch (10mm) to the tire hanging over of the side (both inside and outside). I always recommend 8" or 8.5" wheels for 245's. Most (if not all) tire shops will recommend 225's for a 7.5" wide wheel, but you can typically mount 235's on them without a lot of worry. 235's on a 38mm offset will also guarantee that you'll have no rubbing.

Personally, I'd find 8" wheels if you want to go 245's. Stick with 235's if you really are in love with that wheel, and can't find a bigger size. But that's just my opinion, of course.

Hey Ody, any chance you could do a write-up on Reed's site about rim sizes, offsets, and wheel sizes? Maybe some sort of chart that says if I get a 20x8.5 rim what range of offsets and tire sizes work with it? I say this because people are ALWAYS asking about it and I know I will be to if I can ever save up the money for rims.

odysseus · #11 (**permalink**) 05-24-06, 09:21 AM

Yes, I agree. Maybe this weekend, I'll take some measurements and do an FAQ writeup. Rather than simply say "this fits, this doesn't", I'll explain the math, what offset is and how it relates to backspacing, recommended tire widths for a specific rim width, what the interferances (upper pinch bolt, lower control arm, etc) are on the CTS, etc. This way, everyone will know what measurements are critical and how to match wheels and tires to our fenderwells.

I plan on being under the car for the long weekend, anyway, for an oil change, and to get my V sways out of the cobwebs, and on the car. I may do a test fit of my 14" 5-lug brembo brakes (and take pics), but I still need to get the rear rotors resurfaced and cleaned off (or find new ones) before I mount them permanently.

Totally off topic, but does anyone know where I can find a set of Brembo rear 14.4" rotor rings (for two piece brakes with floating rotors) in a 28mm width?