i wud go with the normal plugs jer ,and change often. unless ur engine makes it hard to access the plugs ie 6a12tt, den u need to go with the long lasting plugs like the iridiums
6A12NA and 6A12TT is similar, hard to access the plugs on the rear bank.
u hv to take out the intake manifold first, which requires alot of work.
which is why Iridium plugs are recommended, they can last 100K km.
if the engine is just 4 inline (like 4G63NA or 4G63T), then ok coz easy to get access to the plugs.
Finally! Yes, Finally, we will have the chance in Japan and at NihonCar.com to test drive one of the most awaited Lexus cars since the launch of the IS series...