Posted by Max on June 14, 2000 at 18:50:25:
In Reply to: Re: Hotter plug posted by Cousin Briar on June 14, 2000 at 04:56:08:
Good explanation of the hotter vs colder plug. Most plugs these days will operate correctly in a fairly wide range of operating conditions if the fuel mixture, and timing are correct. Platium plugs or any of the other precious metal coated plugs tend to have less metal errosion when firing, thus the gap remains within the ability of the coil to fire more miles(kilometers), that is how the car manufacturers are able to claim 100,000 mile tuneups. Inreality they also have coil on plug ignition systems, and computer controlled air/fuel rations over all engine operating conditions. Also the 100,000 mile interval only applies to a select few who operate in mild temperatures, not alot of stop and start and no trailer towing or commerical service. Mostly an advertising advantage. Until we have coil on plug ignition systems (up to 80KV capability w/o overheating the coil), computer controlled feedback fuel systems, we will still need to change the plug or at least check and correct the gap at the recommended intervals. New Savages won't be in the $4300 range when all the above is on them either. Besides the inconvience of changing the plug, every misfire allows some of the unburned fuel to get into the lubrication system diluting it and increasing the chance of engine damage. If you need a hotter plug for normal operation, I suggest you get the fuel system trimmed back to correct. An example of someone who could use colder plug is a oval or round track racer who has a short idle time, and then minutes of WFO running with a coast to the pits or victory lap. Throttle basically has 2 positions, idle and WFO, not much in between.