Which glow plug for my nitro engine?

To get the best performance out of your engine use the correct rc engine glow plug. RC glow plugs will wear down eventually and is always a good idea to have a couple glow plugs spare just in case.

.5 to .12 engines use number 3 rc glow plugs.

.12 to .18 engines use number 3 or 4 rc glow plugs.

.21 to .28 engines use number 5 or 6 rc glow plugs

Depending on the time of year, you may prefer to use a rc glow plug that is warmer (such as a number 3 in a .18 engine) when the season is colder. Using a number 3 glow plug in the summer though will make it wear quicker.