Pixel Pitch Explained: P2 vs P3 vs P4 vs P5 for Vehicle LED Displays
Pixel pitch is the single most important spec affecting both image quality and price of a vehicle LED display. But the “best” pixel pitch depends entirely on viewing distance. This guide explains how to choose the right pixel pitch for your specific application.
What Is Pixel Pitch?
Pixel pitch (measured in millimeters) is the distance between the centers of two adjacent LED pixels. A P3 display has 3mm between pixel centers. Smaller pitch means higher resolution — but also higher cost, higher power consumption, and more heat.
The Viewing Distance Rule
The fundamental formula: Minimum viewing distance = pixel pitch x 1000 (in mm)
- P2 = 2m minimum viewing distance
- P3 = 3m minimum viewing distance
- P4 = 4m minimum viewing distance
- P5 = 5m minimum viewing distance
Below this distance, viewers see individual pixels (the “screen door” effect). Above this distance, higher resolution provides diminishing returns — the human eye can’t distinguish the extra detail.
Vehicle Application Analysis
| Application | Typical Viewing Distance | Recommended Pitch | Why |
|---|---|---|---|
| Taxi top display | 5-30m | P4-P5 | Audience is across the street or in following vehicles |
| Taxi top (premium) | 5-30m | P3 | Crisper text, better for brand logos |
| Bus destination board | 10-50m | P5-P7.6 | Simple text/numbers, long viewing distance |
| Bus side panel | 3-20m | P3-P4 | Closer pedestrian viewing, complex content |
| Rear window transparent | 2-15m | P3.91-P7.8 | Close viewing in traffic, transparency trade-off |
| Truck/trailer side | 5-50m | P4-P6 | Highway viewing, large format compensates |
Cost Comparison
| Pixel Pitch | Relative Cost | Pixel Density | Best For |
|---|---|---|---|
| P2 | 100% (baseline) | 250,000 dots/m2 | Premium taxi, close-range only |
| P2.5 | 75% | 160,000 dots/m2 | High-end taxi, brand campaigns |
| P3 | 55% | 111,111 dots/m2 | Professional taxi, best value |
| P4 | 35% | 62,500 dots/m2 | Standard taxi, bus side panels |
| P5 | 25% | 40,000 dots/m2 | Budget taxi, bus destination, truck |
| P7.6 | 18% | 17,301 dots/m2 | Bus destination board only |
The Sweet Spot: P3 for Taxi LED
For taxi top displays, P3 is the sweet spot. Here’s why:
- Resolution: At 960x320mm screen size, P3 provides 312×104 pixels — enough for logos, text, and simple video
- Viewing distance: 3m minimum — perfect for urban traffic where audiences are 5-20m away
- Cost: 45% cheaper than P2 while delivering 90% of perceived quality at typical viewing distances
- Power: Lower pixel count means less power draw and heat
- Durability: Larger LED components (SMD1415 vs SMD1010) are more resistant to vibration
When to Choose P4 or P5
P4 and P5 make sense when:
- Budget is the primary constraint
- Content is primarily text and simple graphics (not video)
- Display is on a bus or truck (longer viewing distances)
- Fleet size is large (100+ units — savings multiply)
When to Choose P2
P2 is worth the premium when:
- Display shows complex video content
- Brand campaigns require pixel-perfect logo rendering
- Viewing distance includes pedestrians at 2-3m (taxi at a red light)
- The display is a flagship showcase unit