Quote Originally Posted by ezem View Post
* GH
does using iridium spark plugs will make our LPG powered car run better? FC and performance wise...
I doubt if iridium spark plugs would give better FC or performance. It is a matter of matching the proper plugs for your engine's operation. Typically it seems most cars will operate well enough on ordinary plugs but some might require colder sparkplugs to prevent engine shake during idle.

Improved FC will still require proper fuel system & engine tuning. I am currently observing our Mazda3 after Auto-Xer has swapped the stock plugs with a colder set. He also tuned the LPG system as well. Hopefully this will cure the idle vibration problem without causing other problems.

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As of our "fleet" of LPG cars:
Mazda3 - idle vibration cured by lpg system tuning *speedlab and colder spark plugs as well.
City 1.3L idsi - bad idle initially caused by an overheating (due to a failed radiator fan), cured by replacing all 8 sparkplugs with a new stock sparkplug set from Honda.
Camry 2.0L (gen2) - running fine since conversion.
CRV 2.0L (gen2) - running well except for the "sinok" problem when starting from an idle stop, greenfuel with speedlab is looking for a solution.
Sentra 1.3L N16 - running fine since conversion.
Corolla 1.6L AE111 - running fine, lpg system slightly detuned to provide marginally better FC at cost of lower peak performance.
Expedition (gen1) - running well since conversion.