Best Spark plug for the 850 T or V70 ?

Post by **Red-Arrow** » 06 Nov 2010, 17:26

I have just to complete the full service of the engine and the only thing missing is a set of new spark plugs.

What do most people use in there engines? I do not run high boost so I don't need a colder plug. OEM spec is fine.

Are there any plugs I should avoid? Champion plugs in Saabs are a waste of money for example.

Post by **confused_al** » 06 Nov 2010, 17:43

You cant go wrong with OEM plugs (I think Bosch is the maker for turbo plugs). People here and in VS reported all kinds of problems with various other plugs.

Post by **Ozark Lee** » 06 Nov 2010, 18:02

I just use the plain old Bosch coppers on mine. Like Al said, you can never go wrong (at least yet) with Volvo OEM parts.

I think the old plug number I used was Bosch number FR7DC but they have changed their numbering scheme and I can't recall the new part number.

The gap is critical - 0.028 or slightly less
.

...Lee

Post by **Red-Arrow** » 08 Nov 2010, 02:41

I like NGK plugs as they always make durable plugs. I just bought 5 OEM plugs made in Germany apparently for $35, is that average?

Post by **jreed** » 08 Nov 2010, 04:20

I like the Bosch FR7DC (aka 7555) in my '97 855 GLT. I had the OEM platinum plugs and found that if I started the car and ran it for less than about 1 minute, it would not start easily the next time due to platinum tip fouling. The copper FR7DCs have not exhibited this problem. I need to regap them about every year or so, so I usually just replace them since they only cost about $2 each.

Post by **jblackburn** » 08 Nov 2010, 06:49

The Bosch Coppers just don't last long enough for me. I was getting misfires after only 20-some,000 miles on my engine, so I decided to go back to the Autolite Platinums I'd run before.

I found that it's very finicky about the gaps with other plugs - I needed to set mine to .026" to keep it from occasionally hiccupping, but now it runs great! The Autolites get me better gas mileage than the Copper's too (and no, it's not my imagination - I drive the same route every day)

My car came with NGK's installed, and ran pretty well with them too. They're good plugs, those are the only kind I use in our Hondas.

Post by **Red-Arrow** » 08 Nov 2010, 19:14

Copper is a better conductor than platinum but copper is much softer and will deteriorate faster. Platinum is much harder and resistant to pitting and erosion but the spark is less intense by a very small percentage.

Where on Earth do you find plugs for $2 each?

Dad03 · Post by **Dad03** » 08 Nov 2010, 19:33

Autolite Platinum for $2.99. Gap .028. Have had no problems.

Allen in Hemet · Post by **Allen in Hemet** » 08 Nov 2010, 20:34

I have good luck /experience with Denso E3 plugs. They are pregapped, and the gap is not adjustable on these "Diamond Fire" plugs. I have been using them for the past year/approxamtly 15,000 miles with no missfire issues due to the plugs. R/ Allen

carboncow · Post by **carboncow** » 23 Nov 2010, 18:23

Guys need some input, hopefully I'm not truely hijacking.

What is the gap needs on copper NGKs? I tried the Bosch Platinum Plus (as recommended by FCP) and have had nothing but issues. The local autozone had this NGK listed as I requested a copper only option after reading so many posts.

Do I gap to .028 the same as the Bosch? Or is there something unique for a different plug manufacture?