Either Denso or NGK are OEM plugs. I personally prefer NGK ignition parts. You can look up the part number on NGK's online catalog. The Laser Iridium OE type is what you want. I see DILFR6D11 for 120K intervals, verify your application.

Home - NGK Spark Plugs

NGK Spark Plugs (U.S.A.), Inc. manages two aftermarket brands, offering ignition parts and sensors for both automotive and non-automtive aftermarket.

ngksparkplugs.com

Then look on rockauto for price. Enter your zip code for shipping cost. You should come out to around $75 plus tax and about $9 shipping for 6 plugs. I'd guess the dealer might charge two hour or three to change plugs? (So that might add $200-300 in labor in addition to parts markup, so $400-500 maybe?) They might get it done in an hour but they will charge the book rate whatever that is.

And use the rockauto 5% off code, scroll to the newest post:

RockAuto Discount Code

Hey guys, I got this discount code but it will expire on October 24th and I won't be using it. I don't know if it can be used more than once so whoever uses it first might be the only one to get it. All you do is put this number "38391513162399" without the quotes in the "How did you hear...

www.toyotanation.com

 

Thanks, I only see "ignition coils" on NGK 's website. I don't see any spark plugs for a 2017 highlander.

 

Since you are payng Toyota to service, you will not be buying your own parts. Toyota will only be using their parts.

 

Plugs are good until 120k miles.

 

I didn't know what year yours was so I randomly picked 2015. Looks like you might want to try Denso then for the 2017:

Find My Part - DENSO Auto Parts

Searching for your parts in the DENSO part catalog is easy. Simply select the type of part you are looking for along with the year/make/model of your vehicle.

densoautoparts.com

Which I see FK20HBR8 Iridium Long Life. Again, verify your application and compare to your owner's manual.

 

parts.toyota.com for price of the spark plug. Since you're doing it at the dealership, you won't have a choice of spark plug.

 

Denso's, but why are you replacing them?. Seems like at least 30k miles early. Maybe 2 to 3 years early?
Wait until you have to have the valve cover gaskets replaced! , do it then.

 

Wait until you have to have the valve cover gaskets replaced!

Why do you say that? People having problems with Valve Cover Gaskets on this engine? First I've heard about it.

 

Does the owner's manual say to change plugs or is it the dealer? Like everyone says, these plugs are good until 120K

 

it says to in the maintanence schedule book.

 

60k or 72 months for s spark plug change in the maintenance section of the manual.....at least on a 2017 with the 2GR-FKS engine (the V6)
I remember seeing this when I bought the car.....my last Toyota said either 100K or 120K.

 

Looks like all "FKS" engine is subject to the shorter interval...same thing goes for the Tacos as well

Spark plug change question

I've searched for "spark" in the 3rd gen Hybrid forum and come up with zero hits so here's my questions: The Hybrid uses platinum platinum plugs with a life of 60K. I pushing 59K now on our '18. I've always replaced my own plugs but it seems like the rear three require the intake to be removed...

www.toyotanation.com

Replacing Spark Plugs at 60K mile service

Just got a quote from my dealer on a 60k mile service for my 2016 TRD Sport MT. I knew it would be expensive since the XFER case, transmission and...

www.tacomaworld.com

 

The rear bank of plugs has lots of things in the way, so it's going to be fairly labor intensive, so that means more hours you have to pay the Toyota dealership

 

Toyota uses Denso or NGK. In fact my 05 4runner came with both from the factory. I thought it was unusual, but several 4runner owners I know found the same thing.

Either plug are fine. I wouldn't deviated from them.

Also save yourself some money and find a good independent as opposed to the dealer.