Spark plugs

[nutco]

Has anyone used this spark plug, Bosch WR7DC Spark Plug,
In my Volvo at the moment i have NGK BPR6ES Spark Plugs, these have performed well with hardly any wear on the electrode after 5 years,
I can get a deal on the Bosch but never used them, what do people think,?

[griston64]

I thought the NGK were very cheap anyway. I'm sure I only paid under £3 each when I bought mine in December

If they worked well before why not stick with them ?

[Jebus]

Personally I would go with the Genuine Volvo plugs, and at about 12 quid a set of 4 they are cheap as well

[griston64]

https://www.ebay.co.uk/itm/GENUINE-V...53.m1438.l2649


No connection to me

[Laird Scooby]

Originally Posted by griston64

https://www.ebay.co.uk/itm/GENUINE-V...53.m1438.l2649


No connection to me

They look suspiciously like Bosch plugs and i believe Bosch have a plant in Mexico.

I'd go for the NGK plugs myself, i've used both Bosch and NGK over the years but have always found NGK have had the edge on Bosch for reliability and longevity.

In fact when i got my current 760, the previous owner informed me the plugs were recent. When i removed them and checked the gap, it suggested about 70k miles of wear, assuming they were correctly set in the first place.

Looking back through the MoT history, that placed them at 10 years old and still working well, although slightly reluctant to staart in the cold - with a gap of 1.4-1.5mm it's hardly surprising!

I wasn't too surprised they'd been in that long, he also told me it had a recent oil/filter change "a few months back" - found the receipt that said 4 years previous!

[classicswede]

Genuine Volvo plugs are Bosch but made to much stricter quality control than the conventional Bosch plugs. I've had too many issues with faulty Bosch plugs to continue using them.

NGK are good plugs but ebay is full of fakes, make sure you buy from a UK factor.

Whilst Bosch have more than the fair share of defective plugs ones that work are still decent. The only plugs that will almost never work are Champion

[Ian21401]

940 est.1992, 2.0L, non turbo, 217,000 miles.
Acquired car in 2005 and initially fitted Volvo plugs then changed to Bosch WR78 super 4 which I have fitted since then. So far as I am aware the electrode gaps, there are 4, are non adjustable and do not appear to change over the life of the plugs. They seem to go on for ever, so much so that I only change them every fourth oil change, ie: 2yrs of 24,000 miles, and no problems yet that I am aware of. On previous cars, Morris Marina and my daughter’s Ford Orion, I used NGKs for many years without any problems but gapped them at every oil change and replaced them at 12,000 miles.

[AndyV7o]

NGK all the way.
Extremely low failure rate, very reliable and long lasting.
I used to work at a motor factors, reps would try and get us to swap to other makes, but never got anywhere. I dont recall a single faulty NGK.

[Laird Scooby]

Originally Posted by Ian21401

On previous cars, Morris Marina and my daughter’s Ford Orion, I used NGKs for many years without any problems but gapped them at every oil change and replaced them at 12,000 miles.

Was it a CVH Orion? There was a time when the only plugs the CVH would run on was Bosch - Ford even sent out a TSB to tell dealers to ONLY fit Bosch plugs (not even Motorcraft plugs, their own brand!) but that was when the CVH first came out.

Obviously as time went by, people like NGK, Denso, Beru and so on worked out the "magic ingredient" in Bosch plugs and produced "CVH-compatible" versions of their own so these days it won't make a lot of difference. I should also mention this seemed to be prevalent on new engines only, those that were run-in didn't seem to be so fussy.

As Andy says above, NGK are extremely good plugs, the ones that came out of my 760 were NGKs and replaced with the same type. I did have to replace them after about 6k miles though, not through any fault of the plugs but the original HT leads breaking down, arcing and burning the insulator!

[Ian21401]

Yes Dave, a CVH Orion. I moved to NGK from Champion decades ago but cannot remember why. I probably made a note somewhere in the relevant vehicle’s maintenance log. I should look it up. I changed to Bosch with the present Volvo as just about everything else on the car is Bosch and the plugs in question are readily available.