GTI spark plugs

[mjmallia]

Just checking if Bosch FR5KPP332S spark plugs are good for a stage 1 GTI.

Got the NGKs on at the moment and looking to try the Bosch ones

[ROH ECHT]

I did a search and those came up as not for, do not fit, the mk5 2.0t FSI. I went to Bosch's site and these are what they list as a fit; FR6KPP332S.

I used only oem until switched to NGK PFR7B plugs. The PFR7B are a few dollars cheaper per plug but better. They need to be gapped no more than 0.028".

[mjmallia]

Thanks.

Just gone to the UK Bosch site and netted the car details and the ones I mentioned (5) come as as recommended not the 6 version.

http://www.bosch-automotive-catalog.com/en/internet/ECAT-RS/vehicle-info/-/vehicle/equip/VWW/2711/-dglkrhc755haqd560fiufk7044td5m6i

[mjmallia]

VW seem to have moved to Bosch as the recommended and NGK as an alternative. Lots of differing information out there 🤪

Ordered a set of 5’s the other day so will give them a try I guess

[ROH ECHT]

6 rated plug is the recommended heat rating when stock for the MK5 GTI 2.0t FSI. 5 rating might be for the standard Golf. Hopefully other GTI owners will chime in and verify which one you need. I've recommended the PFR7B plugs to some having misfire issues at high revs and boost when tuned and they work. The oem 6-rating should be best for your stage 1 tuned MK5 GTI.

Going to a hotter plug like a 5 means you could run into pre-ignition issues because the tips may not cool fast enough...so just watch your data for misfires and check the plugs for fouling(melted or over-heated tips due to heat not dissipating quickly) from time to time. Test your gap when new and months later to check if the gap is holding and working well or widening due to excessive heating on the tips. When you add HP to stock figures you usually will need to go a colder plug that cools faster, or higher rating...like a 7. I do not understand why the Bosch UK site states a 5 rating other than it only lists a selection for a Golf 2.0 rather than more specifically the Golf GTI 2.0turbo FSI. I've only seen a 6 or 7 rating ever suggested for these.

[Dan_FR]

The numeric heat range differs between the brands - it is not a direct crossover/comparison

[pudding]

Bosch's heat range is the opposite to that of NGK.  An NGK 7 = a Bosch 5.

I looked up the OEM double platinum plug on NGK's site and it's a 7, which matches Bosch's OEM heat range of 5.

The NGK BKR7EIX seems to suit these engines extremely well, running noticeable smoother at idle than most other plugs I've tried. 

People fit them thinking it's 1 grade colder than stock, but it isn't.   

Don't be tempted with 8 and 9 range plugs, or gapping.  Neither are necessary if the engine is tuned properly.

[mjmallia]

Thanks all

Fitted them yesterday and took the 5 month old PFR7S8EG NGK's out to fit the FR5KPP332S as had an odd idle, having had a lot of engine work done and only the sparks left.

It definitely feels more responsive from cold and idles a lot better now and mpg has gone from 17mpg to 23.5mpg which is a result for my short journeys.......I will monitor things, but generally happy.

[mjmallia]

@Pudding - I will keep the NGK BKR7EIX in mind for the future having just got these

[ROH ECHT]

Thanks for commenting guys.
I was confused as to why the Bosch UK states a '5' and the Bosch US stated a '6'...likely they rate differently regionally as well, right? Perhaps it was rated differently due to fuel quality, factory recommended octane, etc.?

Regardless, I didn't want the OP to pick up a set that was incorrect for optimum performance...so, grateful for your confirmation.