Offset to backspacing conversion
| Offset | 6" wide rim | 7" wide rim |
7.5" wide rim |
8" wide rim | 8.5" wide rim | 9" wide rim | 9.5" wide rim |
| 15 | 3.59 | 4.09 | 4.34 | 4.59 | 4.84 | 5.09 | 5.09 |
| 25 | 3.98 | 4.48 | 4.73 | 4.98 | 5.23 | 5.48 | 5.48 |
| 30 | 4.18 | 4.68 | 4.93 | 5.18 | 5.43 | 5.68 | 5.68 |
| 35 | 4.38 | 4.88 | 5.13 | 5.38 | 5.63 | 5.88 | 5.88 |
| 40 | 4.57 | 5.07 | 5.32 | 5.57 | 5.82 | 6.07 | 6.07 |
| 45 | 4.77 | 5.27 | 5.52 | 5.77 | 6.02 | 6.27 | 6.27 |
| 50 | 4.97 | 5.47 | 5.72 | 5.97 | 6.22 | 6.47 | 6.47 |
Backspacing is the distance from the back lip of the rim to the mounting pad in the center of the rim, by the lug holes. This is what you can easily measure at the swap meet, etc.
Stock GVR-4 wheels specs:
- 6" wide with 46 mm of offset (see bold above).
- Bolt pattern is 4x4.5 (114.3mm), measured from center to center of adjacent
holes (not diagonal).
- Wheels are hub centric with a 67mm bore.
Backspacing to Offset
conversion
table taken from
http://www.rsracing.com/tech-wheel.html
| Wheel Width (in) | 3.25" BS | 3.5" BS | 3.75" BS | 4.0" BS | 4.25" BS | 4.5" BS | 5.0" BS | 5.25" BS | 5.5" BS | 5.75" BS | 6.0"BS |
| 5.5 | 0.00 | 6.00 | 12.00 | 19.00 | 25.00 | 32.00 | 44.00 | 52.00 | 57.00 | 63.00 | 69.00 |
| 6 | -6.40 | 0.00 | 6.00 | 12.00 | 1.00 | 25.00 | 38.00 | 44.00 | 51.00 | 57.00 | 63.00 |
| 6.5 | -12.00 | -6.00 | 0.00 | 6.00 | 12.00 | 19.00 | 32.00 | 38.00 | 44.00 | 51.00 | 57.00 |
| 7 | -19.00 | -12.00 | -6.00 | 0.00 | 6.00 | 12.00 | 25.00 | 32.00 | 38.00 | 44.00 | 51.00 |
| 7.5 | -25.00 | -19.00 | -12.00 | -6.00 | 0.00 | 6.00 | 19.00 | 25.00 | 32.00 | 38.00 | 44.00 |
| 8 | -32.00 | -25.00 | -19.00 | -12.00 | -6.00 | 0.00 | 12.00 | 19.00 | 25.00 | 32.00 | 38.00 |
| 8.5 | -38.00 | -32.00 | -25.00 | -19.00 | -12.00 | -6.00 | 6.00 | 12.00 | 19.00 | 25.00 | 32.00 |
| 9 | -44.00 | -38.00 | -32.00 | -25.00 | -19.00 | -12.00 | 0.00 | 6.00 | 12.00 | 19.00 | 25.00 |
| 9.5 | -51.00 | -44.00 | -38.00 | -32.00 | -25.00 | -19.00 | -6.00 | 0.00 | 6.00 | 12.00 | 19.00 |
| 10 | -57.00 | -51.00 | -44.00 | -38.00 | -32.00 | -25.00 | -12.00 | -6.00 | 0.00 | 6.00 | 12.00 |
| 10.5 | -63.00 | -57.00 | -51.00 | -44.00 | -38.00 | -32.00 | -19.00 | -12.00 | -6.00 | 0.00 | 6.00 |
| 11 | -69.00 | -63.00 | -57.00 | -51.00 | -44.00 | -38.00 | -25.00 | -19.00 | -12.00 | -6.00 | 0.00 |
| 12 | ---------- | ------------ | -69.00 | -63.00 | -57.00 |