Denso (3297) SK20R11 Iridium Spark Plug, Pack of 1

I just changed all 6 plugs on my 2003 Sienna at 91K miles. The original plugs are NGK IFR6A11 and still worked. Toyota's service manual says to replace them at 120K but my dealership recommended it during the 90K service. So I thought I should give it a try. Toyota's manual recommends either the NGK or this Denso. There are two Denso replacement; this one is supposed to last 120K miles and the other one is supposed to last 60K. I am glad I bought this one as the replacement of the back 3 plugs is very difficult. It took me about 10 minutes for the front 3 plugs but 2 hours for the back 3. Most time was spent on unscrewing the bolts and plugs as they were very tight and untouched for 6 years and the room for ratchet movement is small. I also bought GearWrench 5/8" swivel magnetic socket (80546) for the job, which turned out to be extremely useful for the back 3 plugs. I immediately felt improvement after the spark plug replacement. The engine runs much smoother and quieter...Read more

Denso IK20 = Electrode .4mm (rated 30k)high performance, low mileage
NGK BKR6EIX-11 = Electrode .6mm (rated 60k-70k) mid, mid
NGK IFR6T11 OE = Electrode .7mm (rated 120k) stock performance, high mileage
Denso SK20R11 (OEM long life)= Electrode .7mm (rated 120k) stock performance, high mileage

Hope this helps. These are 4 top-rated plugs. Rated mileage varies on these plugs depending on various factors of your engine. Keep your engine fuel clean and u should be fine. Toyota recommends the SK20R11 but I found in the owners manual that the discontinued "IFR6A11" is also comparable replacement, the new one is the IFR6T11.

I've tried SK20R11 and it lasted about 110k but there was some compression leak (plugs were still good though). All of these are excellent plugs. I have not tried IK20s yet but will purchase some though the 30K life is pretty short. I hate the 1mz-fe engines with the 3 rear plugs which are a *bleep* to change. Anyone have...Read more

I purchased these plugs in April 2010 to replace the original plugs that were in my 2003 Toyota Camry. The car was starting to run a little rough and I realized the plugs had never been changed. The Denso SK20R11 were the same as the plugs that were originally installed. I was surprized when I removed the old plugs at 122,000 miles how good a condition they were still in. I replaced the old plugs and the car ran a little smoother. I certainly recommend these plugs if they are typical of the Denso Iridium plugs.