Spark plug heat rating

[Fcw75]

I replaced my car original spark plug NGK LFR5A-11 with NGK LFR6A-11 (the stockist told me this model for my car). Is it OK, will there be any problem?

[King]

dun worry

[Mr_b20]

if your car still moving as normal means no problem?

 

[Fcw75]

The after the 'dun worry' doesn't instill confidence in me leh.

[Trex101]

The diff is only 70'c-100'c(combustion temp) from the number 5 plug. Good for high rev but not so good for slow city driving. Effect is carbon may build up if combustion temp not high enough.

[Bearbear1494]

Second that opinion. My car uses BKR-5E plugs, but most places carry BKR-6E plugs. On the 6E plugs, the car feels more willing to rev from the mid range onwards. After an enthusiastic 5K on the plugs, changed them out with another set of 6E plugs. The next 5K were somewhat more sedate & upon changing, noticed carbon build-up on the plugs which wasn't present on the previous set.

 

Conclusion, 6E plugs need higher revs on my engine to sustain the self-cleaning function.

[Fcw75]

Ok, thanks terence. I have used the 3 bottles of Schaeffer oil I bought from you last nite...good stuff inside but I wouldn't say for the outside...haha.

 

So back to the spark plugs, if I changed every 10K instead of 20K then it will be fine since the carbon build up will not be that much?

[Fcw75]

Good information. Yes, you are rite...a lot of places carry heat rating 6 plugs, hard to find plugs with heat rating 5.

 

Ah, that's what I get off the internet too. The colder the plug, the better it is for highway driving...e.g. NSH driving.