NGK or Bosch?

[jberks]

Went into my local Halfords yesterday and they have a 3 for 2 offer on plugs. With a 4 pack at a very reasonable £10 compared to £4-5 ea for the singles - it means £20 for the 12 instead of around £50 buying in singles. The problem is that the charts these guys have go off are a bit vague. So, off the interweb I've figured that the correct NGK for my 2000 E240 is the PFR5G-11. Fine so far, but the originals are Bosch but I can't find any reference to the equivalent Bosch plug and Bosch don't have a chart on their web site. (good enough reason not to buy in my book!)

So Anyone think there is any difference? Would the NGK be fine ? Anyone know which the correct Bosch ones are?

Can't believe I am making this much fuss over a lousy spark plug! It was much easier on the old escort!
thanks guys,
Julian

 

[Myros]

either or

not much in it these days JB. I go Bosch as my corner shop has the Yttrium ones for £1.75 each. They don't do an NGK version that is souped up, just the standard copper core, so I go fancy Bosch on both SL and C280. make sure you use a torque wrench if you can get one in there. 25Nm max. If not, go hand tight, and very gingerly, half a turn beyond. I know that's Grandma's egg-sucking, but I recently spent a whole day watching my mechie drill and tap out a broken plug in the SL that seemed to have been done up to 200Nm.
Good luck

 

[SLinKyjoe]

not that this is much help but NGK made a new design spark plug for the SLK when it was first introduced. so the NGK version will be okay as theywill know what Mercs need if it is anything different to others.

I should think an MB dealer will be able to source the correct number Bosch plugs for you to go back to Halfords with. or maybe try a different motor spares place?

 

[pascal]

Here are the PFR5G-11 (F1000-57290) by NGK. They are usually more expensive than the Bosch. So £2.50 a piece seems good value.

These are the Bosch Platinum+4 (F1000-61924). Are these the ones you are replacing, JB:

They are both for 112 series engines.

Pascal

 

[jberks]

Thanks guys. The ones in there at the moment look 'standard' - single bar over the top (anode?) so both the above options look like an improvement.

I had a look at one yesterday and its a perfect light grey so all looks well, but the centre pin is down to 2-3mm or so - not sure how long they are to begin with but the gap looks a tad larger that it should be - a spoon handle feeler gauge would do.

It interesting when you start to look into these things. The bosch ones have 4 'bars' and the NGK an irridum centre. I guess they have to differentiate somehow but I do wonder whether its marketing, a 0.1% improvement or a real difference.

Myros, its good advice, thanks. I don't have a torque wrench so I will go with the hand tight + 1/4 - 1/2 turn I think.

I had a good look round and whilst a bit tricky in places, I don't see 2 hours labour for someone who's done it before. That would equate to 10 mins a plug and it looks more like 5 mins each for me, taking my time, having never touched it before, not really having the best equipment and not having a mechanics dexterity.

I will pick up the plugs during the week, have a go at the weekend and let you know how long it really takes!

 

[Myros]

I'm only human..

.. and only just that. JB, I've just checked the Bosch website, and for the torque-wrench free amongst us, they recommend hand-tight, then 90degrees turn on new, flat-seat plugs, and hand-tight and a further 15 degrees on conical seat and replaced plugs. Looks like I was bit generous with the turns there. However, for the 20 years that I did not use my torque-wrench on my plugs because it wouldn't fit in the engine bays I had, I did half-turn, 180 degrees beyond hand-tight and never stripped a thread or broke a plug. Can't be all bad. and that must have been over 40 plug changes I did.

 

[jberks]

Yup. All the ones I have done over the years (Lada, Viva, Escort, Astra, Granada etc) haven't been even that scientific - just hand tight and pinch them up with a standard ratchet bar. Just don't swing on it. Never threaded or bust one yet - though did lose one on the A1 in the astra once. Not sure why the Merc scares me so much - somehow its just seems a bit grown up when the others were toys.
Daft really, I could afford to fix the Merc if I damaged it, whereas if I'd buggered up the others when I had them, Id was too skint to have done much about it.

 

[mark999]

try http://www.sparkplugs.co.uk

lots of info

 

[pascal]

£90.80 inc VAT from above compared to £20 at Hellfords.

Must be great profit in plugs even allowing for Halfords buying power discount.

JB: Did Halfords quote on the Iradium NGKs

 

[jberks]

£90.80 inc VAT from above compared to £20 at Hellfords.

Must be great profit in plugs even allowing for Halfords buying power discount.

JB: Did Halfords quote on the Iradium NGKs

The £20 was for the ones on the chart - but I'm pretty sure they weren't PFR5G-11. Then as I said, I didn't have a lot of confidence in the chart which is why I didn't buy them!

It definately said E240 and from memory said '96- but I was a bit suspicious from the price that they were actually normal copper plugs rather than the 60k platinum, let alone irridum variety.

 

[kebo57]

Went into my local Halfords yesterday and they have a 3 for 2 offer on plugs. With a 4 pack at a very reasonable £10 compared to £4-5 ea for the singles - it means £20 for the 12 instead of around £50 buying in singles. The problem is that the charts these guys have go off are a bit vague. So, off the interweb I've figured that the correct NGK for my 2000 E240 is the PFR5G-11. Fine so far, but the originals are Bosch but I can't find any reference to the equivalent Bosch plug and Bosch don't have a chart on their web site. (good enough reason not to buy in my book!)

So Anyone think there is any difference? Would the NGK be fine ? Anyone know which the correct Bosch ones are?

Can't believe I am making this much fuss over a lousy spark plug! It was much easier on the old escort!
thanks guys,
Julian

“So Anyone think there is any difference?”

I’ve been using NGK in V8 lanny & offroader for past 20 years no problem