# The wheel differencer... (Offset calculator)

**URL:** <https://forums.speedlife.net/t/the-wheel-differencer-offset-calculator/85424>\
**Category:** SON240sx Automotive\
**Created:** [April 30, 2005, 5:36pm UTC](https://forums.speedlife.net/t/the-wheel-differencer-offset-calculator/85424 "2005-04-30T17:36:13Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\
**Post date:** [April 30, 2005, 5:36pm UTC](https://forums.speedlife.net/t/the-wheel-differencer-offset-calculator/85424/1 "2005-04-30T17:36:13Z")

</div>

Will S14 wheels (5-lug) clear an S13 that has coilovers and Z32 30mm  
brakes?

I wrote a cheezy script to do some calculations:

[http://son240sx.ca/wheelcalc.php](http://son240sx.ca/wheelcalc.php)

Basically comparing an S13 wheel (15x6 +40) to an S14 5-lug wheel  
(16x6.5 +40), the S14 wheel is clearly inside the wheel well more by 2.5"  
(or 6.35mm).

Now spoke design as well as offset determine clearance so I’m curious to  
know whether these will still clear everything?

Here’s the code to determine how much further inside or outside the wheel  
well the new wheel is:

```auto

// Commented out...
// $size1 = 15
// $width1 = 6
// $offset1 = 40

// $size2 = 16
// $width2 = 6.5
// $offset2 = 40

    $clearance = (($width1/2) + ($offset1/25.4)) - (($width2/2) + ($offset2/25.4));

```