Bosch Spark Plugs

[Laher]

Hi,

I purchased some Bosch Super Plus spark plugs from ebay :

http://www.ebay.co.uk/itm/290919753134? ... 1497.l2649

But my friend who is installing them have told me they are too large, and doesn't want to risk putting them in, as they could knacker up my engine.

Car is 1989 320i 4 Door Saloon - M20 Engine

Pictures are attached.







Are these indeed wrong ?

I have read some topics on spark plugs, and most seem to recommend the cheaper NGK sparkies, as bosch can make make the engine idle a bit higher. Is that true?

Thanks.

[Morat]

NGK are preferred by most zoners. I haven't heard about Bosch and high idle, but NGK give a nice smooth idle and long life in my experience.

[Meatballs82]

I've had feedback about BMW engines not liking Bosch plugs before. The correct Bosch plugs for an E30 are WR7DC+

The best plug to use in an M20 is NGK BPR6ES

[chh137]

NGK .... ZGR5A ?

[Laher]

Hi someone has just given me ngk zgr5a.

Are these correct? Can engine knacker up if I install these?

Thanks

[Laher]

I googled it and it seems most are saying zgr5a are perfect.

Meatballs why do you say the others are better? Thanks

[HairyScreech]

I have actually come across this recently and as expected did a bit of digging.

For High Comp E1 and E2 engine code carse then its the BPR6ES
For Low comp K1 cars (facelift) then the ZGR5A is the ticket.

Having recently changed to the ZG they do stay cleaner in a low comp lump, I always found the car would get grumpy if shunted about at low speed or idled for a while, Easily cleared up buy a quick hard run.
Now I am going to put that down to the BPR6ES being a touch too cool to burn the carbon off properly at low loads in the LOW COMP lump.
The difference in the plug heat ranges is about 100 degrees (given like for like conditions) so the 6 heat range in the low comp is a touch cool and the 5 is pretty much spot on.

Will obviously update when I next pull the ZGR5A plugs out.

P.S. Forget anyone but NGK when it comes to plugs.