Calculating rims offset

[gr8golf88]

Fellow forumers, may I request for some advices on the following.

I like the look (e.g. flush) of the following rear setup for E92 LCI: 19X10 ET+37 with 265/30 tyres. If I would like to change to 19X9.5, what should the offset be -- in order to maintain the same look (e.g. flush.)

The reason for the change: I feel that 19X10 is too wide for running 265/30 tyres -- make it looks like a donut. BTW, I am running Continental ExtremeContact DW Tyres.

I tried to calculate using the following formula, but not sure if this is the correct way:

(rims width in mm / 2) + offset = total distance from the start of the back side/brake side of the rim to the mounting plane.

So, this is for the 19X10 ET+37: (10*25.4/2)+37 = 291

So, for the 19X9.5 setup, the offset is: 291-(9.5*25.4/2) = around ET +43

Does this sound correct? :screwedu:

Thanks.

 

[wt_know]

Re: Calculating rims offset

this is what i got from e90post.com wheel offset calculator

19x10, +37, 265/30/19
19x9.5, +31, 265/30/19 (if +30 more aggresive by 1mm if +32 less aggresive by 1mm)

result = 12mm MORE clearance on the strut side, and the outside edge of the wheel will extend to THE SAME point as the stock wheel

i'm pretty sure that your offset must be smaller (more aggresive) than +37 in view that your rim width reduce by 1/2 inch

 

[gr8golf88]

Re: Calculating rims offset

this is what i got from e90post.com wheel offset calculator

19x10, +37, 265/35/19
19x9.5, +31, 265/35/19 (if +30 more aggresive by 1mm if +32 less aggresive by 1mm)

12mm MORE clearance on the strut side, and the outside edge of the wheel will extend to THE SAME point as the stock wheel

Thanks bro. Can plesae post the link to the calculator here. Also, not sure if I understand the last sentence. Care to elaborate?

So, I should go for 19X9.5 ET+30?

 

[wt_know]

Re: Calculating rims offset

here is the link --> Wheels and Tires Forum Sponsored by The Tire Rack - E90Post - BMW 3-Series (E90 E92) Forum

key in the current and new wheel parameter and click Compute

what i meant is wheel width is reduce by 1/2 inch (10" to 9.5") means it will retract from the edge (fender). in order to push the wheel to the same point at the edge (fender), your wheel offset must be more aggresive ... isn't it logical?

find a workshop bro-bro type, say interested to buy wheel (cheong one also ok), test fit with 19x9.5 +30 with your current Conti DW 265/30/19 ... you will see the result immediately

 

[gr8golf88]

Re: Calculating rims offset

here is the link --> Wheels and Tires Forum Sponsored by The Tire Rack - E90Post - BMW 3-Series (E90 E92) Forum

key in the current and new wheel parameter and click Compute

what i meant is wheel width is reduce by 1/2 inch (10" to 9.5") means it will retract from the edge (fender). in order to push the wheel to the same point at the edge (fender), your wheel offset must be more aggresive ... isn't it logical?

find a workshop bro-bro type, say interested to buy wheel (cheong one also ok), test fit with 19x9.5 +30 with your current Conti DW 265/30/19 ... you will see the result immediately

Very clear Prof. wt_know. Thank you.

Need to PM Robot this rims offset calculator.

 

[wt_know]

Re: Calculating rims offset

you're welcome
take your time to find your favorite wheel and perfect setup
new wheel install gives orgasm ya ... hehe

 

[gr8golf88]

Re: Calculating rims offset

Yeap...better than sex bro...kekeke...

 

[kenntona]

Re: Calculating rims offset

The precise number is +30.65, so yeah, +30/+31 should do fine. +30 will be very flushed assuming you have quite some negative camber.

 

[gr8golf88]

Re: Calculating rims offset

The precise number is +30.65, so yeah, +30/+31 should do fine. +30 will be very flushed assuming you have quite some negative camber.

Thanks bro Cantona.