For cold weather(about 60 degrees and belower) a hotter glow plug is usally needed. hotter glow plugs will help the engine maintain the corrext operating tempature.
Step2
For hotter weather(if your sweating) use a colder plug if your glow plugs dont last as long and burn out you need a colder plug and you should install a head shim as well.
Step3
if your engine is making a loud pinging noise this is called detonation you will need to install a head shim it is caused by to much compression with a hot glow plug
Step4
dont run out of gas it can damage the glow plug as it leans out when fuel levels get low and can damage the glow plug thurn the engine off by stopping the fly wheel or plug the exuast
Tips & Warnings
when changing a glow plug clean the head off first you dont want any dirt in your engine
on 1/26/2008
Great tips including the what ifs. Coasting into the gas station on E is something that happens more times now then ever due to the high gas prices. Before anyone takes the chance they should read up and know what they are risking. Thanks for the information.
Enthusiast 
Comments
TheDon said
on 6/6/2008 Great advice. Thank you for sharing.
grouch said
on 1/26/2008 Great tips including the what ifs. Coasting into the gas station on E is something that happens more times now then ever due to the high gas prices. Before anyone takes the chance they should read up and know what they are risking. Thanks for the information.