Platinum Vs Iridium Spark Plugs, 2000 Avensis 4Afe Lean-Burn

[Edwardius]

Hi there,

As per the title, I have a 2000 lean-burn, non-vvti 1.6 avensis (4afe). I changed the plugs about 3K miles ago for NGK BKR6EP-13 double platinums on a recommendation. I started noticing a hesitation around 1200rpm and some pinking, which I found strange.

Anyway, I checked the ignition lead and coil resistance and they were well within spec, so I switched the plugs back to the old ones (Denso K16RU-11, with nickel electrode) and the hesitation is now gone, the pinking reduced but she's still quite unhappy on any form of incline.

Now, I recently read some documentation which states that the application of my engine (AT220) requires Iridium plugs only, specificially Denso SK20RP13, presumably for the lean-burn system.

Now, my question is, will changing to the recommended Iridium plugs make any appreciable difference?

Thanks!

[Konrad C]

I would only use the Denso SK20RP13 plugs, which I have fitted. They are expensive but the cost is worth it.

They last 60,000 miles or more and are designed for the high operating temperature of lean-burn, so will not cause the problems you are experiencing. Iridium has a very high melting point compared Platinum and Nickel .

Inferior spark plugs may melt causing damage to your engine - very expensive.

[Edwardius]

Thanks for the reply, I suppose it'll work out cheaper in the long run!