Oh ok, but what I meant is here on the open road we have in summer 40 degrees celcius plus, have measured around 60 degrees at oil cooler height on my pajero. So would assume engine's here get more heat than the one's running in UK. It is actually quite hard to find a plug here with a heat range higher than 6. So was just wondering in that sense if that would have an effect on the heat range of plug you should use.
Sorry, me and my questions, ha ha. It's just here we often have to add extra fans or bigger radiators on cars we drive hard due to the heat.
thanx again.
Correct me if I am wrong, but I thought the higher the number, the "colder" the plug.
Colder plug help prevent detonation, but also are not very good at cleaning itself.
So you use a colder plug if you run high power to prevent det.
But if you plug are too cold, it will not clean itself and foul; therefore it won't work correctly.
When you turn the boost up, you normally use 1 or 2 step colder spark plug to help prevent det.
Modern ignition are quite good that you can get a way using plug that are slightly colder.
If you have high intake temperature, I would use a colder plug also.
Like most people say, a 7 heat range should be fine for the amount of power you are running.
