Notices
Series I Wheels, Tires, Brakes & Suspension

18x8.5 with a 38 offset

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 04-11-2006, 09:57 PM
  #1  
Registered User
Thread Starter
 
iammemares's Avatar
 
Join Date: Mar 2006
Location: Phoenix
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
18x8.5 with a 38 offset

Found a set of wheels I can live with for OK money.. They are Konigs from discount and will accept the pressure sensor.

The Discount computer is saying the with 8.5 wide, need to maintain 42 or more offset to avoid tire rub.

I know that a bunch of you are running 18x9s or 19x9s or wider with a 35-40 offset.

So whats the reall deal, is an 18x8.5 with a 38 offset and a 245/40R18 goona rub front or back with stocj height suspension??

Response appreciated as I would like to order the wheels on Wed. Tomorrow.
tried to insert pic of the wheel. hope it works. Thank you very much
[IMG]www.konigwheels.com/catalog_product_details.cfm?CategoryID=1&ss_id=419[/IMG]
Old 04-11-2006, 10:00 PM
  #2  
Registered User
Thread Starter
 
iammemares's Avatar
 
Join Date: Mar 2006
Location: Phoenix
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Man,

Sorry for the really bad spelling in that one. Guess I was typing a little to quickly.

How do I get a picture to show up?? And what about that 38 offset?
Old 04-12-2006, 12:02 AM
  #3  
#1 Legend
iTrader: (1)
 
BigOLundh's Avatar
 
Join Date: May 2004
Location: TEXAS
Posts: 3,904
Likes: 0
Received 0 Likes on 0 Posts
Discount tire told me both set of wheels i bought would not fit. Both fit fine.

You should be ok with +35. I am running 19X9.5 + 40 on the rear.. and it fits fine.

-hS
Old 04-12-2006, 01:28 AM
  #4  
Registered User
 
MrWigggles's Avatar
 
Join Date: Jan 2003
Location: Houston
Posts: 1,232
Likes: 0
Received 2 Likes on 2 Posts
iammemares,

I have 245/40-18's on 18X8.5 that have a 45mm offset. If mine are 45mm and the ones you want to get are 38mm, that difference is 7mm. 7mm is a little over a quarter of an inch.

I can comfortably say that there is at least quarter of an inch of clearance between the outside of the tire and the fender currently on my vehicle in the front wheel wells. I would give yourself a 95% or better chance of those wheels fitting without issues and it should look very very nice with the tire going almost all the way out to the fender.

In the back you will have even more clearance to work with. (In the back have 275/35-18's on 18X9.5 with a 42 offset )

-Mr. Wigggles

Last edited by MrWigggles; 04-12-2006 at 01:32 AM.
Old 04-12-2006, 02:02 AM
  #5  
Shootin' from the hip
 
Revolver's Avatar
 
Join Date: Apr 2005
Location: Sydney, Australia
Posts: 7,584
Likes: 0
Received 0 Likes on 0 Posts
I am running 18x8.5 with 38 offset (Enkei RP03's) and 235/40R18 rubber (Michelin PS2's) and I haven't had any rubbing problems.

Before you buy 245's, consider 235's. I'm not sure about the availability and cost comparison in the US but I reckon the slightly lesser width sharpens turn in and reduces tyre squirm (a little like the 225's on the stock rim). I appreciate others may have a different view and prefer the widest rubber they can get away with but let's face it, the chassis is hardly overwhelmed with power and I believe it's important to try and keep the sharpness that Mazda's engineers dialled into the car.
Old 04-12-2006, 03:31 AM
  #6  
Registered User
 
RX4life's Avatar
 
Join Date: Jan 2005
Location: Burnaby, BC
Posts: 821
Likes: 0
Received 0 Likes on 0 Posts
will fit easily..
Old 04-12-2006, 09:16 AM
  #7  
Registered User
 
MrWigggles's Avatar
 
Join Date: Jan 2003
Location: Houston
Posts: 1,232
Likes: 0
Received 2 Likes on 2 Posts
The problem with the 235/40 is the sidewall is shorter and the diameter is smaller (if there is a perceptable difference in squirm, that would be the cause.)

This means it will ride a little harsher and will add another 1% or so error to the speedo (The RX-8 already reads at least 2 MPH high at 60MPH. With the 235/40 it will be 3 MPH)

The differences between the 235/40 and 245/40 tires are going to be small, but those are the differences.

-Mr. Wigggles
Old 04-12-2006, 09:52 AM
  #8  
Registered User
Thread Starter
 
iammemares's Avatar
 
Join Date: Mar 2006
Location: Phoenix
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Thanks

Thank you for the feedback.

I also appreciate the thought on the 235s. I also believe a 235 would do well. The tires I want to run is the M/L Pilot Sport Cup. This is only available in a 235/35. This would be seriously short, about 6 MM overall. And I agree with you assesment that a 235 is probably enough tire and a good balance for an otherwise stock RX.

The focus on performance is why I am staying with an 18 and not going with monster tires that just increase rolling resistance and unsprung mass.

Looks like I am gonna give the 38 offset a go.
Old 04-12-2006, 07:57 PM
  #9  
Shootin' from the hip
 
Revolver's Avatar
 
Join Date: Apr 2005
Location: Sydney, Australia
Posts: 7,584
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by MrWigggles
The problem with the 235/40 is the sidewall is shorter and the diameter is smaller (if there is a perceptable difference in squirm, that would be the cause.)

This means it will ride a little harsher and will add another 1% or so error to the speedo (The RX-8 already reads at least 2 MPH high at 60MPH. With the 235/40 it will be 3 MPH)

The differences between the 235/40 and 245/40 tires are going to be small, but those are the differences.

-Mr. Wigggles
Agree with all that Mr Wiggles. Not trying to oversell the 235 option - just something I prefer.

The speedo error I can live with. If anything, it builds a little more safety margin in when you're being careful NOT to speed (e.g. school zones, etc).

As for ride, I've actually found the ride improved. However, that may be due to the ride difference between the OEM Bridgestones and the Michelin PS2's I've fitted rather than any diameter change. Can't say enough about them - great tyre (oops, sorry - tire ).
Old 04-12-2006, 09:47 PM
  #10  
Original Turbo 'd Auto !!
 
09Factor's Avatar
 
Join Date: Mar 2004
Location: Surprise its Az!
Posts: 2,126
Received 4 Likes on 4 Posts
Nice looking rims, but ouch 30 Lbs!
I thought my Falkens were heavy at 23
Old 04-12-2006, 10:12 PM
  #11  
Shootin' from the hip
 
Revolver's Avatar
 
Join Date: Apr 2005
Location: Sydney, Australia
Posts: 7,584
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 09Factor
Nice looking rims, but ouch 30 Lbs!
I thought my Falkens were heavy at 23
Agreed - the OEM's are 20lbs from memory.

Why add 50% weight for looks?? Personal choice I guess.
Old 04-13-2006, 12:14 AM
  #12  
Registered User
 
rotorhead335's Avatar
 
Join Date: Feb 2006
Location: Central California
Posts: 124
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Revolver
I am running 18x8.5 with 38 offset (Enkei RP03's) and 235/40R18 rubber (Michelin PS2's) and I haven't had any rubbing problems.

Before you buy 245's, consider 235's. I'm not sure about the availability and cost comparison in the US but I reckon the slightly lesser width sharpens turn in and reduces tyre squirm (a little like the 225's on the stock rim). I appreciate others may have a different view and prefer the widest rubber they can get away with but let's face it, the chassis is hardly overwhelmed with power and I believe it's important to try and keep the sharpness that Mazda's engineers dialled into the car.
Revolver:
Very intelligent response. Thanks.
Jeffrey
Old 04-13-2006, 12:53 AM
  #13  
Zoom-Freakin'-Zoom
iTrader: (5)
 
swoope's Avatar
 
Join Date: Jan 2004
Location: orlando, fl
Posts: 14,602
Received 36 Likes on 32 Posts
Originally Posted by Revolver
Agreed - the OEM's are 20lbs from memory.

Why add 50% weight for looks?? Personal choice I guess.
oem

24 lbs.

beers
Old 04-13-2006, 12:54 AM
  #14  
Zoom-Freakin'-Zoom
iTrader: (5)
 
swoope's Avatar
 
Join Date: Jan 2004
Location: orlando, fl
Posts: 14,602
Received 36 Likes on 32 Posts
http://www.1010tires.com/WheelOffsetCalculator.asp

this is a BIG help..

beers
Old 04-13-2006, 12:59 AM
  #15  
Shootin' from the hip
 
Revolver's Avatar
 
Join Date: Apr 2005
Location: Sydney, Australia
Posts: 7,584
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by swoope
oem

24 lbs.

beers
Ahh, yes - that's right.

Sorry, we're on metric and my memory of the imperial measurements can be hazy.
Old 04-13-2006, 01:00 AM
  #16  
Shootin' from the hip
 
Revolver's Avatar
 
Join Date: Apr 2005
Location: Sydney, Australia
Posts: 7,584
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jeffreyteuber
Revolver:
Very intelligent response. Thanks.
Jeffrey
No sweat Jeffrey - glad it made sense to someone!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
fourwhls
RX-8's For Sale/Wanted
7
02-20-2019 05:16 PM
hufflepuff
Series I Wheels, Tires, Brakes & Suspension
6
05-30-2016 10:45 AM
Kahl
RX-8 Parts For Sale/Wanted
5
08-20-2015 11:49 PM
Richard Paul
RX-8 Parts For Sale/Wanted
3
08-17-2015 01:49 PM
R2D2X8
West For Sale/Wanted
0
08-17-2015 08:47 AM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: 18x8.5 with a 38 offset



All times are GMT -5. The time now is 03:50 AM.