Hi everyone, i was thinking about the spark plugs i hade changed out on my car a few years ago (for my 2009 rx350). I had ordered them from Rauto.
i just looked today in the owners manual, which says to use: FK20HR11 plugs.
on the rock site, there are 2 different Denso Iridium plugs. there was the Iridium TT (4704) plug and the Iridium long life (3426). Both plugs have a slight gap difference too. I installed the 4704 plugs. Is this okay? I think the car runs fine. I do find that at idle the engine isn't supper smooth, i can stiff feel the engine is on, and ever so slight valve tick on cold startup.
And info or advice welcome. Thanks
fab

 

90919-01247 aka FK20HR11 aka 3426 is the only plug specified for your engine, everything else is experimentation.

 

Highly suggest you cahngethem over to the specified plugs for peace of mind. Next time consult your manual for the appropriate specs, good luck.