Which spark plug is better?
 

NGK BPR6ES, BP7ES, or BPR8ES
Can some one explain which one is better and why? I tend to like the cooler the better, but is there any risk/disadvantage?
Thanks.

It depends on the duty of the car.

Hotter plugs will be better in some circumstances and Colder Plugs in others - there isn't an absolute or there would only be one plug type.

Gently driven car that needs to start and run well in traffic BP6 Heat range is good particularly on carbs.

Some people even recommend BP5 but I think this is a little too hot.

Normal use car driven at higher speeds for longer duration BP7

Track Day/Race/Rally BP8 but at winter temperatures in the UK at -5 degC it may not start.

Thanks Chris, What do you think about the 8?

8 only designates the heat range. You want to run the coldest plug you can without fouling. 8 is pretty cold, not sure what car you have or what you will be doing with the car, but if it's for the street it might be too cold.

yes.
I run 8's in my 930.

just as a note. I did a test of a bosch W4, same as ngk 8, in my 77 911s. even though the plug used from my brothers 930, it was clean after an 800 mile trip, but BLACK after driving around town. also, it NEVER fouled even though I ran my 911 rich.
that's the need for hotter plugs, cold starts and rich idling/city driving.
carbs I would run hotter, EFI you can run colder.

In the SC models the lower compression cars use a hotter plug (normal)...the NGK7 series for the US models....the ROW 930-10 I'm driving uses NGK9's (recommended by comparing the Bosch unit in the specs manual)....and works/goes perfectly with that colder plug.

Thanks guys.
Mine is a none turbo 88, for normal street driving with lot of slow traffic. The reason why I like to use as cold as I can to keep the oil temp as low as possible in traffic. Does it make sense or it won't matter much?

Spark plugs.
 

For our M/Y 86 3.2 just a daily driver/no track, we use the BPR6ES.

Gerry

Can I shift the topic a bit. Do you guys think it's better to remove plugs when engine is cold or a little warm?
Thanks.

Lots of old school tuners will drive the piss out of the car, pull over and pull the plugs out hot to check the tips. So I guess it depends on what you are doing. Sometimes its really not fun pulling plugs out of a hot car.