Platinum/Iridium spark plugs

I purchased 4 Denso SK16R11 from Amazon for $25. No reason not to buy OEM plugs for $25 and the job is fairly easy and should be done in 30 minutes.

Waiting for my strut bar and PCV valve to arrive as I have to remove common parts for each job.

 

My fuel mileage has dropped to the floor. Last fillup was 32 mpg. UGH!

I am going to put my Denso's back in. They looked OK when I changed them last year.

I'll keep you posted on the results. Now at 164209 miles , started at 143802, = 20407 miles.

Aug 24 2015
Over the weekend I put my old Denso's back in. When I pulled the Bosch plugs I photoed each one and then the Denso I put back in. The tip of the plug looked good on the Bosch plugs, very white insulator. The center tip of the plug looks identical to the Denso plugs too. I cleaned the old plug threads and liberally coated them with anti seize compound, Permatex. The Bosch plugs came out slowly with lots of torque on the wrench handle even though I used anti seize compound on them when I put them in.The Denso plugs screwed in nicely by hand all the way down and I torqued them to 12 ft lbs. 13 ft lbs is the spec, but it felt too tight for me.

Yesterday I drove to a local lumber yard to check out something and the Prius ran freer than before, like it did when I first got the car.

today I ran some errands and it felt good to see mileage of over 60 mpg @ 60 mph on local roads. My mileage went from 48 mpg to 51 mpg. Aug 25 2015, I got excellent fuel mileage today. It feels good to be back in the hi mileage group!

So this my result. I regained mileage that i used to have. I think that the Bosch Iridium spark plugs seemed to work but failed to deliver after many miles on them. This isn't satisfactory to me. Especially so since I put the original Denso's back in and it now gets better mileage.

So keep the Denso spark plugs or the NGK plugs as specified by Toyota and save gas.

.The first 4 pics are the Bosch Iridium, the second 4 are the Denso's. The Bosch Iridium shows a lot of heat wear on the body of the spark plug. I cleaned the threads of the old Denso's before I photoed them so they look nicer. LOL

I included a photo of a spark plug with a short piece of hose on it. My old 5/8" socket rubber insert was so worn out that it wouldn't pick up the spark plug. I used the hose to snag it and pull it out.

The last photo shows a spark coil and there is a band around it in the middle. The first two coils even had some oil on it. I wiped them off before installation. Any idea where the oil came from?
Results, the Bosch Iridium plugs didn't hold up the good mileage.

 

I changed my Bosch plugs for the old Denso SK16R11 plugs. The first impressions was that they worked better than the Bosch Iridium plugs.
Last Friday evening my wife & I went to Grand Rapids for a White Caps ball game. I had hard time even getting 50 mpg. I started with 51.3 mpg and ended up with 50 mpg. It would have been much worse if I hadn't hypermiled the whole way.

I wonder where the mileage is going? I will have to get my mini VCI going and look over the stats. If I figure out anything I'll tell ya.

 

...the Bosch plugs looks like they are stingy on the iridium...given it is one of the rarest elements on the planet, this is understandable, but I went with other ones

 

Nkg and denso are the best, even the German cars use them.

Bosch sux.


iPhone ?

 

I've always heard that you should only ever use Japanese parts for Japanese cars, and German parts for German cars, ie. NGK/Denso in Japanese imports only, and Bosch in German imports only.

 

I alot of VW, Audi, and BMWs came with NKG spark plugs from the factory.

Not sure if today is still the same.

 

get the iridiums at advanced auto online and use this coupon code: A124 so you get them at the same price as platinum .

 

My Yamaha Twin Jet boat does not call for iridium plugs. Many do use iridiums, as do I. As soon as I installed them my engines ran smoother. I only change the iridiums every other year vs every year for regular plugs.

I shop around and can always find NGK iridiums for under $10. The last eight plugs I purchased were $7.92 each on Amazon.

 

The oil is probably coming from a slightly leaking engine valve cover.

 

I'm glad y'all like to play under the hood but I'm an old fart, was a wrench and ride for years with all things GM, then tried Ford's for 10 years. I bought a 2008 Prius in 2010 used with 15000 miles on it, thought I'd take it to 200k but when it was going through a quart of oil per 5000 miles and the mileage dropped to 38-42 mpg. Had 120k on it, had changed coolant and plugs at 100k was running synthetic 5w30 (Royal Purple). Screw it replaced it with a 2013 Prius V wow, what a car.

Posted via the PriusChat mobile app.

 

I just saw on RockAuto that the Denso's are $4.90 a plug and that the Bosch irridiumwas OEM ($4.78) on 2006 models.

 

Bosch has not been a supplier to Toyota for Prius spark plugs. Only NGK and Denso are original equipment suppliers.

 

Yes Pat though the Bosch plugs and filters are sweet


iPhone ?

 

That is as maybe, but I don't think that was Pat's main emphasis.

The poster to whom Pat was replying said:

to which Pat corrected:

 

These are listed for the 2005 Prius as we speak:

More Information for DENSO 5303 ... $4.90
More Information for NGK 5464 ... $5.51
More Information for NGK 4996 ... $5.66
More Information for DENSO 3324 ... $5.78
More Information for DENSO 4701 ... $5.67

= customer's preferred choice.
I only listed Denso and/or NGK based on what I believe to be common responder's preference.