I had my car in to a Lexus mechanic yesterday, and among other things, he said that "someone" had put the wrong plugs into the car (2001 GS430). Since that "someone" was me, I wanted to check with the community here.

I put in NGK BKR6EIX-11, which per sparkplugs.com, and the discussion here, seems to be a preferred plug. Yet the mechanic said they would use Denso SK20R11, which is original equipment item. He claimed that mine are the wrong heat range.

I suspect that he is used to the Denso's and automatically assumed that since mine were different, they were wrong. Or did I indeed put in the wrong plugs (or at least not the preferred ones)?

 

NGK is the 2nd recommended. But Denso SK20R11 is the #1 official. With the SK20R11, once you change it, you will never need to change it again. It goes for 100k.

 

subscribed for when I decide to do my plgs.

 

Thanks for the comment, makes sense to me, and maybe that is what the tech meant. But it does not sound like my plugs are "wrong", as in I should pull them out and replace them - should I?

But I might go ahead and put in the Denso's next time around.

 

subscribed for future ref

 

The plugs you put in are fine. They are the equivalent plug to the Denso SK20R11....Denso calls it a "20" in the heat range which would be the equivalent of a "6" in the Ngk line. He probably doesn't know enough/realize that manufacturers use different heat range designations as it is not standardized for all manufacturers.

Secondly, The difference between the Denso and the Ngk plugs are the the Denso's are a long life plug where the Ngk's are a high performance plug. You won't get as long a life from the Ngk's but they will give better performance.

Anytime anyone from a dealership tells you anything take it with a HUGE grain of salt. 99% of the techs/service writers at dealerships don't know squat about anything outside following the service manual just like you or I could. They are there to make money plain and simple, you don't need to be any good to be a dealer tech, you just need to know how to read english. I'm not saying there aren't guys out there that are good techs at dealerships, but they are few and far between.

 

What kind of "performance" does the Ngk offer over Denso?

 

If I remember it's a smaller electrode. Smaller electrode gives a better spark with less resistance but wears faster as well.

 

I replaced the OEM Denso plugs on my GS430 to the NGK's from sprakplugs.com and have had no problems. More responsive and better MPG's.

 

Thanks guys, I feel relieved now!

 

get a new mechanic