Tire widths for a 8 in wheel
| Section width | |
|---|---|
| Minimum | 215 mm (8.5 in) |
| Ideal | 225–235 mm |
| Maximum | 245 mm (9.6 in) |
Performance Plus Tire calls this a general guide that is not a substitute for the individual tire's published specs. Every tire size has its own approved rim width range and a measuring rim, the width its listed dimensions are measured on.
How rim width changes the tire
Tire Rack explains that a tire mounted on a wider or narrower wheel than its measuring rim changes its section width: about 0.2 inch for every half inch of rim width. Its example is a P205/60R15, measured on a 6.0-inch wheel and approved for 5.5 to 7.5 inches.
Tire widths on a 8-inch wheel
| Section width | Inches | On the chart |
|---|---|---|
| 195 mm | 7.7 in | Outside chart |
| 205 mm | 8.1 in | Outside chart |
| 215 mm | 8.5 in | Within limits |
| 225 mm | 8.9 in | Ideal |
| 235 mm | 9.3 in | Ideal |
| 245 mm | 9.6 in | Within limits |
| 255 mm | 10.0 in | Outside chart |
| 265 mm | 10.4 in | Outside chart |
Performance Plus Tire general chart. The tire's own approved range decides.
Stretch and bulge
A tire narrower than the chart's minimum is stretched: the sidewalls angle outward from the bead to the tread. One wider than the maximum bulges past the rim. Both move the tire away from the shape it was designed to hold. Tire Rack notes that each tire size has an approved rim width range and a measuring rim, the width at which its listed dimensions are taken.
Offset on a 8-inch wheel
| Offset | Backspacing | Front spacing |
|---|---|---|
| −12 | 4.03 in | 4.97 in |
| 0 | 4.50 in | 4.50 in |
| +20 | 5.29 in | 3.71 in |
| +35 | 5.88 in | 3.12 in |
| +45 | 6.27 in | 2.73 in |
Check clearance before you buy
Offset and width tell you where the wheel's lips end up; they do not tell you what is in the way. Before ordering, measure your current setup:
- Inner clearance. With the wheels straight, measure from the inner lip of the current wheel to the nearest suspension part: strut body, spring perch, upper control arm or sway bar link. If the new wheel's inner lip moves in by more than that gap, it will hit.
- Brake clearance. Big calipers sit inside the barrel. The spoke face, not just the lip, has to clear them, which is why a wheel's spoke design matters as much as its offset.
- Outer clearance. Hang a plumb line or hold a level against the fender lip and measure in to the tire's sidewall. A new wheel that moves out more than that gap will stick past the fender.
- Steering and suspension travel. Turn to full lock and check the fender liner, then remember the suspension compresses over bumps. Static clearance is the best case.
Enter both wheels in the calculator above: the outer-lip number is the extra space you need at the fender, and the inner-lip number is the extra space you need at the suspension.
Common questions
Can I put a 255 tire on a 8 inch rim?
It is wider than the chart's 245 mm maximum for a 8-inch wheel. Check that tire's approved rim width range first.
What is the ideal tire width for a 8 inch rim?
225 to 235 mm on the Performance Plus Tire chart.
Is a 205 tire on a 8 inch rim stretched?
Yes by the chart: it is below the 215 mm minimum.
Related calculators
Sources
- https://www.performanceplustire.com/Blog/tire-size-for-wheel-width
- https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=200