plug gaps - horatio
BPR5ES-11 means it has a 1.1 mm gap

BP6ES does not say what the gap is, so what is the gap if there is no gap figure given in the code?

www.spark-plugs.co.uk/pages/technical/ngk_symbol_c...m
plug gaps - horatio
Also what does the "resistor" code mean?

The plugs fitted to the car are BP6ES, (not resistor type).

The plugs recommended by the site I linked to are as follows - resistor type
The site also says the gap is 0.8mm so is the standard gap (i.e. when there is no gap code) always 0.8mm?

Daewoo Nexia 1.5 8V '96

Standard Part (may be Copper, Platinum or OEM Iridium)
BPR6E 1.85+vat (each)

Iridium IX Part
BPR6EIX 5.81+vat (each)

plug gaps - LeePower
Why dont you ring NGK direct & ask them?

Ive rung them before on technical matters & they do bend over backwards to help you.

Contact details are on there website.
plug gaps - horatio
If you click on the NGK chart/picture you get a different version,,it says no number = standard gap but does not say what the standard gap is.
plug gaps - LeePower
Standard NGK plug gap is 1mm
plug gaps - Dynamic Dave
Unless values have changed, a standard plug gap used to be 28 to 32 thou (0.7 to 0.8 mm)
plug gaps - Collos25
Plugs come set to the optimum gap
plug gaps - Chas{P}
Got the NGK book at my desk. Gap depends on the vehicle application. Enlighten me and I will reply with the info.

HTH
plug gaps - Chas{P}
Sorry read the rest of post.

Gap is 0.8mm or 32 thou in old money.

HTH
plug gaps - bell boy
make sure you check the resistance before you fit them
plug gaps - horatio
I imagine you check with an ohmeter but between what points and what value would you be looking for?
I found out resistive plugs are used to stop the HT interfering with onboard electronics, they are not always required depending on your vehicle. It could be that resistive plugs should be used, in which case the wrong plugs have been fitted to this car.

I did phone NGK they said the standard gap on any plug without a gap code would be 0.8mm

plug gaps - 547HEW
For resistor plugs there will be approx 5 K ohm, between terminal and tip of centre electrode.
plug gaps - horatio
Thanks, So I am measuring the resistance along the length of the central core. (haven't got the new plugs yet)
plug gaps - none
I've never felt the need to check the internal resistance of a spark plug, but I can remember 20 odd years ago reading of someone who bought a set of six resistor plugs and found that five of them were open circuit. It turned out that manufacturing tolerances might lead to an air gap within the plug. This gap had no effect on plug performance, but the ohmmeter readings were misleading. I suppose for a real perfectionist the best way to check them is with a Megger.