Subaru B9 Trifecta SUV Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
I am preparing for my 60,000 mile service(which I will do myself) on my 06, and I am finding a conflict on which spark plug to use. My Subaru maintenance manual says NGK ILFR6B. If you go to the NGK(or sparkplugs.com or Amazon.com) site, they say to use NGK ILFR6T11, and the ILFR6B is not for the Tribeca. I can't find any real difference between the plugs except the price(the ILFR6T11 is usually 50% cheaper). They are both the same size, are mid heat range and are iridium. I assume it currently has the ILFR6B in it now but I don't know for sure. Sometimes after a car is out for a while a better plug is available. Any comments?
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #2 ·
The short answer is ILFR6B.

I called the NGK tech support line and asked the question "what is the difference between these plugs and what is recommended for the 06 Tribeca?"

The only difference is the plug gap. The ILFR6B is set to .030 INCHES and the ILFR6T-11 is set to .044. Since the Subaru manual says the gap should be between .028 and .031 then the ILFR6B is the one to use. Since the ILFR6T-11 is cheaper could the gap just be set to .030? The answer is "no" because gaps should not be changed from the original setting any more than .008 INCHES. The reason is that it would create to much angle between the electrodes. Makes sense. Using the ILFR6T-11 set to its original gap of .044 could cause misfiring or worse - cause harm to the ignition system which is designed for a gap of .030 inches.

I told him that NGK(and all sites using the NGK information) are then recommending the wrong plug(ILFR6T-11) for the Tribeca. He said that looks like a distinct possibility and he would follow up on it. It might get changed but I am not holding my breath. I hope it gets fixed, because someday some mechanic is going to rely on that information(mis) and install the wrong plug type if it doesn't.

My theory for why the ILFR6T-11 is cheaper is that it is built for many Toyota models, while the ILFR6B is strictly made for Subarus. Since there are many, many more Toyotas than Subarus it must be due to Volume. They just make a lot more.

I have ordered a set and will be installing them in the next couple weeks. I will let you know how it goes.
 

·
Registered
Joined
·
82 Posts
My supplier shows the correct NGK spark plug. I did check the NGK website and it show the incorrect ones. No listing available for 2007.

My supplier shows my cost at 9.82 and 29.06 list, the Toyota plugs are 7.52 and 22.24 respectively.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #4 ·
At least some one has it right. I found no one with the correct plug listed. Even the local (Schucks) parts store got it wrong. Napa didn't have a clue although they carried both plugs(13.88 for the 6B). 2007 is probably to new to have a listing yet.

I bought mine online for 11.71 each with free shipping. Best price I could find. Pricey but worth it. This should be the last time I ever change them. 9.82 is a good price, but is probably wholesale.
 

·
Moderator
Joined
·
449 Posts
I know this is old but just to confirm: ILFR6B is the proper plug. I just changed mine and that's what I removed.
 

·
Registered
Joined
·
42 Posts
2010 Tribeca at 60,000 miles

Just pulled my plug (Pass side front-most) and it is a NGK SILFR6C11 now at 0.041” at ~60,000 miles. It matches original spec for plug GAP which should be 1.0-1.1 mm (0.039-0.043).
So not sure why so important to change at this mileage. May just let them go another 10k miles.
Dealer said warranty recommendataion is to change at 60,000 miles and quoted $260 for parts and 2 hours of labor. I can buy NGK parts for 50 - 60 dollars.
 

·
Registered
Joined
·
1,776 Posts
Yup... Most people agree the change interval can go quite a bit longer than specs. But some of us change it anyway :)

Consider getting the valve cover gasket replaced while they are there. Fairly common for them to leak in the spark plug tube. That said, mine have never leaked. I wonder if that has to do with the fact that I keep up with oil changes?
 
1 - 8 of 8 Posts
Top