You should choose the smallest MAP sensor that will suit your current needs and future goals. For all naturally aspirated applications, a 2.5 bar MAP sensor is the best choice. For turbocharged applications, use this guide to help you select an appropriate MAP sensor:
| MAP Sensor | Rating (psig) |
|---|---|
| 1 bar MAP sensor (usually stock equipment) | 0.0psig |
| 2.5 bar MAP sensor (standard MegaSquirt hardware) | 21.8psig |
| 3 bar MAP sensor | 29.0psig |
| 4 bar MAP sensor | 43.5psig |