These are the NGK part numbers for Spark Plugs per engine code. From these numbers you should be able to cross reference other brands should you wish.
| Model Detail | Engine Type | Additional Info | Dates | Recommended | Alternate | Upgrade | Gap |
| GOLF Mk2 (84→91) 1.05 | HZ | 50bhp / 37kW GREY COIL | →07/89 | BP6ESZ | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.05 | HZ | 50bhp / 37kW | 08/89→10/91 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.3 | HK | - | 08/83→07/86 | BP6E | BP6ES | BPR6EIX | 0.7mm |
| GOLF Mk2 (84→91) 1.3 | MH,NZ | 54bhp / 40kW | →07/89 | BP6ESZ | - | BPR6EIX | 0.8mm |
| GOLF Mk2 (84→91) 1.3 | 2C,2G,MH,NU,NZ | 54bhp / 40kW | 08/89→07/92 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.6 | ABN,ABX,ACR,EW,EZ | - | 08/83→07/92 | BUR5ET-10 | - | BPR5EIX | Preset |
| GOLF Mk2 (84→91) 1.6 | EZA,HM,HN,PN,RE,RF | - | 08/83→07/92 | BUR5ET-10 | - | BPR5EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | 1P,2H,DX,EV,EX | 8 VALVE | 08/82→09/91 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | GU,GX,GZ,HT,HV | 8 VALVE | 08/82→09/91 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | JH,KT,PB,PF | 8 VALVE | 08/82→09/91 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | RD,RG,RH,RP,RV | 8 VALVE | 08/82→09/91 | BP6ET | - | BPR6EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | KR | 16 VALVE | 85→91 | BCP7ET | - | BKR7EIX | Preset |
| GOLF Mk2 (84→91) 1.8 | PL | 16 VALVE | 10/85→10/91 | BKUR7ET | - | BKR7EIX | Preset |
In addition I just found this really useful cross reference guide.
https://www.sparkplug-crossreference.com/
Search for the number you know, e.g. BPR6EIX
and get the results of other manufactures that provide an alternative, like so:
https://www.sparkplug-crossreference.com/convert/NGK_PN/BPR6EIX