Steering Wheel Cover Sizing Guide
Choosing the right steering wheel cover comes down to one number: your steering wheel's outer diameter in inches. Get this wrong and the cover either won't fit or will slide around. Get it right and you'll get the snug, anti-slip grip you bought it for.
The quick answer
- 18-inch covers — for Class 8 semi-trucks (Freightliner Cascadia, Kenworth T680/T880, Peterbilt 579, Volvo VNL, Mack)
- 14.5"-15" covers (also called "15-inch") — for cars, SUVs, light trucks, and crossovers
How to measure your steering wheel
You need a tape measure and 30 seconds.
- Park, turn the wheel so the spokes are level
- Measure across the wheel from outer edge to outer edge (full diameter, not across the spokes)
- Round to the nearest half-inch
Tip: If you're between sizes, size DOWN. A slightly tight cover is fine; a loose one slips.
Common truck stock steering wheel diameters
| Make & Model | Stock Diameter | Vyonix Size |
|---|---|---|
| Freightliner Cascadia | 18" | 18-inch cover |
| Kenworth T680 / T880 | 18" | 18-inch cover |
| Peterbilt 579 / 389 | 18" | 18-inch cover |
| Volvo VNL | 18" | 18-inch cover |
| Mack Anthem | 18" | 18-inch cover |
| Most sedans & SUVs | 14.5"–15" | 15-inch D-shape cover |
What if your steering wheel isn't standard?
If you've replaced your stock wheel with an aftermarket option (smaller racing wheel, custom diameter), measure first. The most common aftermarket sizes are 13–14 inches. We don't currently make a cover for those sizes — but message us and we'll let you know if it's coming.
D-shape vs round
If your wheel has a flat bottom (D-shape), you need a D-shape cover. A round cover won't sit flush on a D-shape wheel — it wrinkles at the bottom. Our 15" car cover is D-shape specifically because most modern sport sedans and SUVs ship with D-shape wheels.
Still not sure?
Email us your make, model, and year — we'll tell you exactly which cover fits. We respond within 24 hours and we're real people, not a chatbot.