S60 2.5T Spark Plugs: Use only Bosch (or Volvo)!

[JNavas]

I needed to replace the spark plugs in my 2008 S60 2.5T, and I didn't want to spend extra money, so I bought a set of Autolite Iridium XP, thinking iridium is state of the art, so they should be good, right?

They did perform well in the beginning, but after several months I started having rough starts, especially with a cold engine. They immediately smoothed out, so I didn't initially think much about it, but they got rougher, finally giving me Check Engine for Misfiring at Startup.

Long story short: I replaced the Autolite plugs with (OEM) Bosch Platinum Turbo (from FCP Euro), and the rough starting problem is gone! The engine is again smooth as silk.

Lesson learned!

[cn90]

If you did a little homework first, then you would not have bought Autolite plugs. We already talked about it years ago.

Bosch or NGK is fine. I have been using both brands.

Currently, NGK Iridium is what I use.

[JNavas]

1. There's no call for a gratuitous insult.

2. 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.

3. 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.

4. Autolite plugs are usually fine. This was likely an engine mismatch, particularly the iridium. Regardless, Autolite is going away due to the Chapter 7 liquidation of its parent company.

5. NGK plugs are also fine. I've used them for years on both street and track.

[hu5ker555]

NGK 6418 in my 2008 S60 2.5T