Which Diameter EGT Probe Do I Need?

What Diameter EGT Thermocouple Probe do I need for my application?

Question:
I am looking for several EGT sensors for tuning a normally aspirated 2.3 L gasoline engine with 1 5/8” exhaust tubing. Are there any available guidelines about what size EGT probe is recommended, 1/8”, 3/16” or 1/4”?

Answer:
We find that, for most applications, the 3/16” EGT probe is suitable. It’s our most popular probe, with nearly 75% of the probes we sell being this diameter. The 1/8” & 1/4" EGT probes come in handy when an application requires hyper-fast response (1/8”) or extreme durability (1/4”).

Rules of Thumb

• The smaller the probe diameter… the faster the response to dynamic temperature change BUT the probe is less durable.
• The larger the probe diameter… the slower the response to dynamic temperature change BUT the probe is more durable.