Notices
Wheels & Tires 350Z Rollers and Rubbers

How does a 35 offset look? How do "Offsets" work?

Thread Tools
 
Search this Thread
 
Old Sep 13, 2008 | 10:41 AM
  #1  
zcar03's Avatar
zcar03
Thread Starter
Registered User
iTrader: (7)
 
Joined: Dec 2003
Posts: 395
Likes: 0
From: Massachusetts
Default How does a 35 offset look? How do "Offsets" work?

Thinking about a 19x9.5 wheels with a 35 offset. How would that look. Im not educated about offsets? How do they work. Thanks
Reply
Old Sep 13, 2008 | 10:49 AM
  #2  
kelsey_kaye's Avatar
kelsey_kaye
Registered User
iTrader: (4)
 
Joined: Nov 2007
Posts: 1,531
Likes: 0
From: Texas
Default

find a lower offset.
Reply
Old Sep 13, 2008 | 11:04 AM
  #3  
Motormouth's Avatar
Motormouth
Banned
iTrader: (44)
 
Joined: Aug 2005
Posts: 20,190
Likes: 2
From: not here
Default

if you search rim offset on google you can get an idea.

Concept
the simplest way to explain it is that the lower the positive (+) offset, the closer to the centerline of the rim barrel the hub(where the lug nuts are) mounts to the rim.

a zero offset would be the rim completely equal on each side of the hub. every stock car runs positive offset (the Z is +30 stock), which means the hub mounting point is farther towards the outside of the rim than the inside. As the offset lowers(+30,+25,+20, etc), the hub mounting point moves closer to the center of the rim barrel. when the hub starts being on the inside of the barrel centerline, that is negative offset and the number increases as it moves closer to the edge of the rim barrel (-5,-10,-15, etc); so the higher the positive or negative number, the more extreme the distance from the centerline.

Visualize
(the car is on the right hand side of the drawing, the '[' is the rim face, the '----' is the barrel of the rim)

zero offset (+0): hub mounts in the center of the rim

----
iii[
----

positive offset (+15): hub mounts on the outside of the centerline

----
ii[
----

negative offset (-15): hub mounts on the inside of the centerline

----
iiiiii[
----

the Z comes stock with a 18x8 +30 rim. you see where they sit. the higher the offset (+35 for example) the farther IN the rim will sit from the fender. offsets also matter with rim width (obviously).

Rim Width and How It Affects Actualized Offset
To compare different width rims with the same offset (to compare how they will look) I always added the MMs for the size difference like this, since rims are measured in inches, but offsets are in millimeters:

1 Inch = 25.4 Millimeters

So you divide 25.4 in half to get the offset difference (since offset is measured from the center) of a one inch rim width differene, which is: 12.7mm. Then you take that 12.7mm and add it or subtract it to whatever offset you have for the narrower/wider rim to see what a comparable offset would be (I round to 13mm for ease).

example:

18x8 +30 rim (stock) compares to a 18x9 +30 rim (Grand Touring stock rim size [F])

1 inch wider = the rim will sit 12.7mm farther out, so if you wanted the 8 inch rim to sit the same way the 9 inch does, you would need a +17 offset on the 8 inch rim.

*this is only to see how much farther OUT it will stick, inner fender clearance is not taken into account with this method.

Example of Fitment

A very standard rim fitment on the 350Z would be:

19x9.5 +22
19x10.5 +22

that sits fairly flush. most guys on this site run about a +20 offset. that will be semi-flush, not sticking out.

Summary

a +35 offset sucks, you will need spacers

Last edited by Motormouth; Sep 15, 2008 at 01:02 PM.
Reply
Old Sep 13, 2008 | 11:06 AM
  #4  
styles's Avatar
styles
Registered User
 
Joined: Jun 2005
Posts: 339
Likes: 0
From: New York Queens
Default

I didn't know much about offsets either until motormouth thanks
Reply
Old Sep 13, 2008 | 11:24 AM
  #5  
2004Black350z's Avatar
2004Black350z
Exhaust Whore
Premier Member
iTrader: (37)
 
Joined: Sep 2006
Posts: 10,097
Likes: 17
From: NC
Default

dam motormouth. Lol good write up
Reply
Old Sep 13, 2008 | 12:57 PM
  #6  
davidv's Avatar
davidv
Registered User
iTrader: (2)
 
Joined: Jun 2004
Posts: 42,753
Likes: 11
From: Tucson, AZ
Default

Reply
Old Sep 13, 2008 | 02:49 PM
  #7  
carlili4190's Avatar
carlili4190
New Member
iTrader: (6)
 
Joined: Feb 2008
Posts: 432
Likes: 0
From: Evanston/Oak Brook, IL
Default

Originally Posted by davidv
you posted in 5 of those 7 threads shown...
and i bet they all had virtually same response
Reply
Old Sep 13, 2008 | 04:39 PM
  #8  
Spike100's Avatar
Spike100
New Member
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 7,337
Likes: 204
From: Edina, Minnesota
Default

Motormouth,

Best explanation of offset I've seen that is understandable for anyone. Great job!

--Spike
Reply
Old Sep 14, 2008 | 03:44 PM
  #9  
zcar03's Avatar
zcar03
Thread Starter
Registered User
iTrader: (7)
 
Joined: Dec 2003
Posts: 395
Likes: 0
From: Massachusetts
Default

Hey thanks alot very informative. So what would you say is the lowest offset that I can run with no rolling of fenders? Thanks I want them to be as far out. Or is +20 the min.
Reply
Old Sep 14, 2008 | 03:55 PM
  #10  
jray8's Avatar
jray8
Registered User
 
Joined: Oct 2007
Posts: 2,860
Likes: 0
From: Tennessee
Default

great info here!
Reply
Old Sep 15, 2008 | 05:52 AM
  #11  
Motormouth's Avatar
Motormouth
Banned
iTrader: (44)
 
Joined: Aug 2005
Posts: 20,190
Likes: 2
From: not here
Default

Originally Posted by zcar03
Hey thanks alot very informative. So what would you say is the lowest offset that I can run with no rolling of fenders? Thanks I want them to be as far out. Or is +20 the min.
depends on the wheel width.
Reply
Old Sep 15, 2008 | 06:09 AM
  #12  
98Ekhatch's Avatar
98Ekhatch
Registered User
iTrader: (11)
 
Joined: Mar 2005
Posts: 356
Likes: 1
From: VA
Default

more than likely like crap!!!!! un less you just like the way it looks...who cares what others think...and what he said it depends on the width.
Reply
Old Sep 15, 2008 | 06:23 AM
  #13  
jubes's Avatar
jubes
Registered User
iTrader: (22)
 
Joined: Jul 2007
Posts: 2,185
Likes: 2
From: Los Angeles, Ca
Default

Originally Posted by Motormouth
if you search rim offset on google you can get an idea.

Concept
the simplest way to explain it is that the lower the offset, the farther outboard from the centerline of the rim barrel the hub(where the lug nuts are) mounts to the rim.

a zero offset would be the rim completely equal on each side of the hub. every stock car runs positive offset (the Z is +30 stock), which means the hub mounting point is farther towards the outside of the rim than the inside. As the offset lowers(+30,+25,+20, etc), the hub mounting point moves closer to the center of the rim barrel. when the hub starts being on the inside of the barrel centerline, that is negative offset and the number increases as it moves closer to the edge of the rim barrel (-5,-10,-15, etc); so the higher the positive or negative number, the more extreme the distance from the centerline.

Visualize
(the car is on the right hand side of the drawing, the '[' is the rim face, the '----' is the barrel of the rim)

zero offset: hub mounts in the center of the rim

----
iii[
----

positive offset (+): hub mounts on the outside of the centerline

----
ii[
----

negative offset (-): hub mounts on the inside of the centerline

----
iiiiii[
----

the Z comes stock with a 18x8 +30 rim. you see where they sit. the higher the offset (+35 for example) the farther IN the rim will sit from the fender. offsets also matter with rim width (obviously).

To compare different width rims with the same offset (to compare how they will look) I always added the MMs for the size difference like this, since rims are measured in inches, but offsets are in millimeters:

1 Inch = 25.4 Millimeters

S you divide 25.4 in half to get the offset difference (since offset is measured from the center) of a one inch rim width differene, which is: 12.7mm. Then you take that 12.7mm and add it or subtract it to whatever offset you have for the narrower/wider rim to see what a comparable offset would be (I round to 13mm for ease).

example:

18x8 +30 rim (stock) compares to a 18x9 +30 rim (Grand Touring stock rim size [F])

1 inch wider = the rim will sit 12.7mm farther out, so if you wanted the 8 inch rim to sit the same way the 9 inch does, you would need a +17 offset on the 8 inch rim.

*this is only to see how much farther OUT it will stick, inner fender clearance is not taken into account with this method.

Example of Fitment

A very standard rim fitment on the 350Z would be:

19x9.5 +22
19x10.5 +22

that sits fairly flush. most guys on this site run about a +20 offset. that will be semi-flush, not sticking out.

Summary

a +35 offset sucks, you will need spacers

best explanation of offsets I've read
Reply
Old Sep 15, 2008 | 07:21 AM
  #14  
Peteski's Avatar
Peteski
Registered User
 
Joined: May 2004
Posts: 327
Likes: 0
From: Appleton, Wisconsin
Default

Very nice explanation!!!
Reply
Old Sep 15, 2008 | 05:18 PM
  #15  
sam2944's Avatar
sam2944
Registered User
 
Joined: Jan 2008
Posts: 211
Likes: 0
From: Puerto Rico
Default Offset on 18's

Originally Posted by Motormouth
if you search rim offset on google you can get an idea.

Concept
the simplest way to explain it is that the lower the positive (+) offset, the closer to the centerline of the rim barrel the hub(where the lug nuts are) mounts to the rim.

a zero offset would be the rim completely equal on each side of the hub. every stock car runs positive offset (the Z is +30 stock), which means the hub mounting point is farther towards the outside of the rim than the inside. As the offset lowers(+30,+25,+20, etc), the hub mounting point moves closer to the center of the rim barrel. when the hub starts being on the inside of the barrel centerline, that is negative offset and the number increases as it moves closer to the edge of the rim barrel (-5,-10,-15, etc); so the higher the positive or negative number, the more extreme the distance from the centerline.

Visualize
(the car is on the right hand side of the drawing, the '[' is the rim face, the '----' is the barrel of the rim)

zero offset (+0): hub mounts in the center of the rim

----
iii[
----

positive offset (+15): hub mounts on the outside of the centerline

----
ii[
----

negative offset (-15): hub mounts on the inside of the centerline

----
iiiiii[
----

the Z comes stock with a 18x8 +30 rim. you see where they sit. the higher the offset (+35 for example) the farther IN the rim will sit from the fender. offsets also matter with rim width (obviously).

Rim Width and How It Affects Actualized Offset
To compare different width rims with the same offset (to compare how they will look) I always added the MMs for the size difference like this, since rims are measured in inches, but offsets are in millimeters:

1 Inch = 25.4 Millimeters

So you divide 25.4 in half to get the offset difference (since offset is measured from the center) of a one inch rim width differene, which is: 12.7mm. Then you take that 12.7mm and add it or subtract it to whatever offset you have for the narrower/wider rim to see what a comparable offset would be (I round to 13mm for ease).

example:

18x8 +30 rim (stock) compares to a 18x9 +30 rim (Grand Touring stock rim size [F])

1 inch wider = the rim will sit 12.7mm farther out, so if you wanted the 8 inch rim to sit the same way the 9 inch does, you would need a +17 offset on the 8 inch rim.

*this is only to see how much farther OUT it will stick, inner fender clearance is not taken into account with this method.

Example of Fitment

A very standard rim fitment on the 350Z would be:

19x9.5 +22
19x10.5 +22

that sits fairly flush. most guys on this site run about a +20 offset. that will be semi-flush, not sticking out.

Summary

a +35 offset sucks, you will need spacers

Im planning to move to 18, my Z is 17. OEM wheels are 7.5" front and 8" rear. I will go with 8.5" front and 9.5" rear. Wheel manufactures suggest go with 20 offset. What do you think? I believe is a good offset due to I can make changes with spacers.......

Also for this wheel combo I also use mathematics, I think the ideal tires are 245/40 front and 265/40 rear. Tell me what you think, I like the tire a little out of the borders of the wheel, not entirely flush. Thanks
Reply
Old Sep 15, 2008 | 06:53 PM
  #16  
Concave's Avatar
Concave
Banned
iTrader: (1)
 
Joined: Feb 2008
Posts: 1,478
Likes: 0
From: You
Default

motormouth > davidv
Reply
Old Sep 15, 2008 | 07:53 PM
  #17  
Spike100's Avatar
Spike100
New Member
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 7,337
Likes: 204
From: Edina, Minnesota
Default

Originally Posted by sam2944
Im planning to move to 18, my Z is 17. OEM wheels are 7.5" front and 8" rear. I will go with 8.5" front and 9.5" rear. Wheel manufactures suggest go with 20 offset. What do you think? I believe is a good offset due to I can make changes with spacers.......

Also for this wheel combo I also use mathematics, I think the ideal tires are 245/40 front and 265/40 rear. Tell me what you think, I like the tire a little out of the borders of the wheel, not entirely flush. Thanks
That (what you say) will work. Consider 275/40-18 with 22 offset for your rears.

--Spike
Reply
Old Sep 15, 2008 | 08:23 PM
  #18  
davidv's Avatar
davidv
Registered User
iTrader: (2)
 
Joined: Jun 2004
Posts: 42,753
Likes: 11
From: Tucson, AZ
Default

Originally Posted by Concave
motormouth > davidv
motormouth definitely gets the “nice guy” award.
Reply
Old Sep 15, 2008 | 08:33 PM
  #19  
kno's Avatar
kno
Registered User
iTrader: (22)
 
Joined: Aug 2007
Posts: 3,427
Likes: 121
From: MIAMI, Florida
Default

motor mouth ftw this thread should be in the 100 z questions
Reply
Old Sep 15, 2008 | 08:34 PM
  #20  
Spike100's Avatar
Spike100
New Member
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 7,337
Likes: 204
From: Edina, Minnesota
Default

Originally Posted by davidv
motormouth definitely gets the “nice guy” award.
Please forgive me if I misunderstand, but your statement sounds a little condescending.

In fact Motormouth provides the most understandable explanation of offset I’ve seen on this Forum. He took the time and effort to do a great contribution here, and I see that other members appreciate his effort.

--Spike
Reply



All times are GMT -8. The time now is 07:32 AM.