According to Autodata, I should use:

NGK 7822 BPR6ES

According to NGK part finder, I should use either BCPR6E/BCPR6ES (1269/ 2330)

What are the differences between non C?

It looks like the non C has a different socket size:



What you guys use?

Hello, if you use the original ignition module, stick with NGK BP5ES or BP5EY, both are resistor free. If you use a MSD / Mallory / Accel ignition module, best use a 1-step colder plug (BP6ES/BP6EY). NGK standard and V-Power line works very well with those engines. Stay away from "designer plugs" or rare materials such platinum or iridium.

PNZR said:

Stay away from "designer plugs" or rare materials such platinum or iridium.

Click to expand...

Why

I have good results with Bosch +4 plugs in older Fiat 4 cil. and Alfa V-6 engines.
Last summer I put NGK irridium plugs in my old Ducati Bevel Twin, and it idles like it has never done before....

I found a couple of years ago (when getting plugs for my '95 Tipo 1.4) that Bosch and NGK tend to do 2 versions of the same plug, especially for older cars. As was suggested, there are 2 "Hex" sizes... one the bigger old-fashioned size and as an alternative an identical plug with the newer, smaller standard hex nut.

I went with "original" Bosch in the end.

chesh said:

According to Autodata, I should use:

NGK 7822 BPR6ES

According to NGK part finder, I should use either BCPR6E/BCPR6ES (1269/ 2330)

What are the differences between non C?

It looks like the non C has a different socket size:

What you guys use?

Click to expand...

Where did the "C" come from?

E vs ES is that the "S" is I think ???? that the plug is a suppressed version. I won't be quoted on this as a quick look on the NGK site does not definitively decode the E vs ES. A more detailed research may real the difference.

s130 said:

Where did the "C" come from?

E vs ES is that the "S" is I think ???? that the plug is a suppressed version. I won't be quoted on this as a quick look on the NGK site does not definitively decode the E vs ES. A more detailed research may real the difference.

Click to expand...

The c indicates the hex size is 16mm
The s indicates the diameter of the central electrode.

I favour NGK plugs.

jackwhoo said:

The c indicates the hex size is 16mm
The s indicates the diameter of the central electrode.

I favour NGK plugs.

Click to expand...

Thanks for confirming I was wrong

For extra information I've checked my technical records dating back to 1995 when I was in consultation with Fiat Technical about my Stilo Abarth pinking/detonating. This lead to changing the temperature rating of the spark plugs as Fiat could not change the engine map as it would affect the EURO emissions rating which they were not prepared to do. To reduce pre-ignition/detonation you have 3 basic options. Retard Ignition, Increase Fuelling and reduce plug temperature.

So, back to plugs.

Champion - Higher the number the hotter running the plug is
Champion - Lower the number the colder running the plug is
Bosch - Higher the number the hotter running the plug is
Bosch - Lower the number the colder running the plug is
NGK - Lower the number the hotter running the plug is
NGK - Higher the number the colder running the plug is

Note the reversal of the plug number.

The full NGK info can be found here: https://www.ngkntk.co.uk/wp-content/uploads/2016/05/Spark_Plug_Cat_2016.pdf

and go to page 7.