Bosch Platinum 6730 Plugs for S60 2.5T

[June]

One question I have is why 3 sets of plugs in 3 years with only 120K?? My 2004 T6 only calls for plugs every 60K. My car has only had plugs installed at 60, 120, and 180K by Volvo without issue and the Genuine Volvo plugs are not even platinum plugs. I could not tell the difference each time changed. In fact the only time I noticed a difference is recently when the mass air flow sensor was changed at 189K. It was the original. Also the O2 sensors and cats are factory and working perfectly. The MAF sensor replaced is the only repair that made the car feel like it had a "Tune Up". In all these years the engine light only came on once when a turbo vacuum line broke off being hard from age and heat in 2016 or 17.

So my advice to the OP is put Genuine Volvo parts and follow Volvo's maintenance schedule for everything but oil changes. Volvo rigorously tested everything before ever putting our cars in production.

I sincerely hope I misunderstood your OP and the TPI is the same and was just physically shorter thread area. June

[estrekal]

Hi June,
It just seemed like a good thing to do every 10K or so in addition to my air filter since I have been using the "cheaper" plugs. On my wife's past Jetta and now on her Q5, I know the interval on the plugs is 80 to 100K on the iridium. I changed those each one time in the lifetime of owning the vehicles. They're overly complicated to get to in the German car generally.

I was noticing a tiny bit of hesitation over the last few weeks, so I decided I'd change my plugs out. I did just clean the MAF when I had the air box out in July, so who knows? Other than that, no CELs over my ownership of this vehicle. The majority of my issues have come from the front end, all of which has been addressed at the Volvo dealership in town. I'm not confident tackling that type of stuff, sans things like brakes. I appreciate you input.

-Edan

[June]

When my MAF was bad, for example, no engine lights just bad mileage and poor performance. Many times now it took me complaining to the dealer and my mechanic looking at the system through their computer to determine what's wrong. These cars have a crazy complexity to them.

If you plan on replacing the plugs that often use copper plugs. I can say the 98 V70 ran great on AC delco plugs. My husband tried every brand in it. He too hated paying for Genuine Volvo parts. Only the copper AC plugs ran great for lots of miles. Most caused misfires quickly. The ACs could stay the 30K change interval called for in the maintenance schedule for the 98. Best of all they are cheap!

These days I don't ask about his vehicles and he stays out of the service of mine. I found this works best for us as I use the dealer and spend a lot LOL! June

[JNavas]

I should maybe re-phrase what I observed. The threaded area on the plug that I removed was longer (and therefore I'd guess has more threads) than the one I put in. I'm not sure if the overall length of the plug differed or not--I didn't bother to look at the two side-by-side.

That's a red flag. When the length of the threaded area does not match, that means the plug has a different reach, and is unsuitable.

Fine-wire iridium alters the tip projection and combustion characteristics compared to OEM platinum, which is why OEM Bosch Platinum Turbo plugs remain the recommended choice for this specific engine, even if iridium plugs seem to work.

The principal advantage of iridium is plug life, typically 100K–120K miles for double-iridium designs compared to 60K–100K for platinum, though many aftermarket fine-wire iridium plugs (like NGK IX) actually carry shorter 40K–50K intervals.