Stop Guessing. Start Measuring Like a Pro.
If you’ve ever had a customer ask, “Will these wheels fit my car?”, and your answer was “Let me check”, this article is for you.
Fitment issues are among the top reasons for returns and customer complaints in the aftermarket wheel business. But the good news? Learning how to read PCD, offset, and center bore correctly takes just a few minutes—and saves you hours of trouble.
1. What Is PCD (Pitch Circle Diameter)?
PCD tells you:
- How many bolts/lug holes a wheel has
- How far apart those bolts are in a circular pattern
Format:5x114.3 means:
- 5 bolt holes
- 114.3mm diameter of the circle through the centers of the bolts
🔧 Pro Tip: Use a vernier caliper or a fitment chart if the bolt holes are not easy to measure directly.
| Car Type | Typical PCD |
|---|---|
| Japanese Sedans | 5×114.3 |
| European Sports | 5×112 |
| Off-Road Trucks | 6×139.7 |
2. What Is Offset (ET)?
Offset (marked as ET) is the distance between the wheel’s hub mounting surface and its centerline.
- Positive Offset = hub face is closer to the outside (flush look)
- Negative Offset = hub face is deeper inside (wider stance)
Example:
- ET35 = +35mm offset
- ET-10 = –10mm offset
📏 Why It Matters:
- Affects how far wheels “stick out” or “tuck in”
- Influences brake clearance and fender rubbing
- Critical in tuning, off-roading, and stance builds
| Application Type | Typical Offset |
|---|---|
| OEM Sedans | +35 to +45 |
| Widebody Racers | 0 to -20 |
| Trucks & SUVs | +0 to +20 |
3. What Is Center Bore?
Center Bore is the large hole in the middle of the wheel that fits over the vehicle’s hub.
- Measured in millimeters (mm)
- Must match the car’s hub size exactly, or use hub-centric rings
Example:
- If your car hub is 66.1mm, the wheel bore should be:
- Exactly 66.1mm (hub-centric), or
- Larger + hub ring (not ideal but common in aftermarket)
⚠️ Loose center bores cause:
- High-speed vibration
- Poor alignment
- Unsafe wheel fitment
Reading a Real Wheel Spec Example
Let’s decode this marking:20x10J 5x114.3 ET35 CB66.1
- 20x10J → 20 inch diameter, 10 inch width
- 5×114.3 → 5 bolts, 114.3mm PCD
- ET35 → +35mm offset
- CB66.1 → 66.1mm center bore
💡 This wheel fits many Toyota, Lexus, and Nissan models with the correct hub size.
FAQ: Fitment Questions Buyers Ask
Q: Can I use a wheel with a larger center bore?
Yes, with hub rings. But a perfect match is always better.
Q: Can I adjust offset with spacers?
Yes, spacers decrease offset. For example:
- ET45 + 15mm spacer = ET30 effective
Q: What if PCD is close but not exact?
Never force it. Even 1mm off can damage bolts and compromise safety.
Q: Can I re-drill a wheel to change PCD?
Only at specialized wheel shops with certified multi-drilling capability. Not all forged wheels allow this.
The FLEXIFORGED Guarantee
At FLEXIFORGED, every custom forged wheel is:
- Machined to exact PCD and offset specs
- Custom bored to match your car or client’s hub
- Measured with 3D scanners and verified manually
- Marked clearly with laser-etched specs on the back pad
Whether you’re sourcing wheels for a tuner car in Europe or a lifted truck in South Africa—we ensure perfect fitment before production even begins.
Need Help Decoding a Customer’s Specs?
Send us a photo of the car or the current wheel.
📩 Email Jackie: jackie.wei@flexiforged.com
We’ll help you verify specs before you order.