2004 XC70 -- Spark Plugs; Denso Iridiums?

Post by **E Showell** » 01 Jan 2019, 11:23

Thinking of going with Denso Iridiums as spark plugs for the new-to-me '04 XC. Discuss. Any reason not to apart from cost? Strong pros?

Post by **Rattnalle** » 01 Jan 2019, 12:14

Unless they're much cheaper than OEM I really don't see the point.

Post by **E Showell** » 01 Jan 2019, 13:01

100,000 mile service life.

Post by **Rattnalle** » 01 Jan 2019, 13:04

Parts suppliers specified intervals usually don't apply once fitted to a specific car. But let's say it does, are they that much cheaper than OE?

Post by **E Showell** » 01 Jan 2019, 14:00

No, probably more expensive, but I didn't do a direct comparison.

Post by **abscate** » 02 Jan 2019, 00:48

My fleet averages 10-25000 miles per year, so 100k mile plugs would be in the car for 10 to 4 years per car.

I've decided never to let plugs sit in the head for longer than 3 years, even with thread lubricant. That has kept me in cheap copper Bosch or Volvo plugs in the fleet

Post by **E Showell** » 02 Jan 2019, 05:22

I usually use OEM Volvo plugs and change every 30k miles or so. Just surveying the scene for different opinions.

Post by **cn90** » 02 Jan 2019, 07:47

For Iridium, there was some old issue with Denso brand. Search volvospeed for that.

I use NGK Ir and replace every 80K or so.

I use antiseize w/o issues for the last 25 years.

Post by **June** » 02 Jan 2019, 08:55

E Showell wrote: ↑02 Jan 2019, 05:22 I usually use OEM Volvo plugs and change every 30k miles or so. Just surveying the scene for different opinions.

OEM has always been used in my 2004 at the 60K change intervals as in the maintenance schedule without issue. My car at 175K will get it's third set at 180K. It is worth noting my car still has it's original: coils, all O2 sensors, injectors, catalytic converters, and mass airflow meter. Volvo clearly did their homework ahead of time on this subject. My car runs exceedingly smooth even now near the plug change interval. The cost of two sets of plugs over the last 175K and 15 years is negligible. These posts always puzzle me how some other brand or change interval will somehow be better? Then comes the follow up post about misfire codes... when it comes to sparkplugs in Volvos it seems to me, why waste your time and money on something else? June

Post by **Rattnalle** » 02 Jan 2019, 09:33

June wrote: ↑02 Jan 2019, 08:55
E Showell wrote: ↑02 Jan 2019, 05:22 I usually use OEM Volvo plugs and change every 30k miles or so. Just surveying the scene for different opinions.
OEM has always been used in my 2004 at the 60K change intervals as in the maintenance schedule without issue. My car at 175K will get it's third set at 180K. It is worth noting my car westill has it's original: coils, all O2 sensors, injectors, catalytic converters, and mass airflow meter. Volvo clearly did their homework ahead of time on this subject. My car runs exceedingly smooth even now near the plug change interval. The cost of two sets of plugs over the last 175K and 15 years is negligible. These posts always puzzle me how some other brand or change interval will somehow be better? Then comes the follow up post about misfire codes... when it comes to sparkplugs in Volvos it seems to me, why waste your time and money on something else? June

Having all those things original at your milage seems perfectly normal to me from a Swedish perspective. Especially cats and O2 sensors really aren't wear items..

I also agree that using OE at specified intervals is more than good enough to keep the car running well.

I'm not a sucker for blue Volvo boxes but it really doesn't make much sense to hunt around for the things that aren't expensive in blue boxes or where it's very important with exactly the right item as with coils and sensors.