Denso Iridium IK16 in 2.5

[ts johnson]

I searched "ik16" and found few specifics. I know some of you have used the ik20 with success. The salesman at autozone insisted the ik16's were plenty so that's what I bought. Anyone have experience's with the 16's??

[ScoobySchmitty]

Uhm, sparkplugs, right? I used some Bosch platinum 2's in my old 90 I had, didn't notice too much of a difference. Then again, I didn't replace the wires, either.

[blitz]

The 16 is a hotter plug than the 20. In fact, 16 is the hottest plug in the Denso iridium range according to the Denso site.

 

All the documentation I've seen shows 20 to be the recommended heat range for the 2.5 (for a Denso plug).

 

http://www.densoiridium.com/findmypart.php

 

If using an NKG plug, the correct heat range is a "#6" in their system.

 

By going to a hotter than recommended plug, you'll probably end up with spark knock if you drive normally. The ECU'll retard the timing and you'll end up with elastic throttle response and worsened fuel economy.

 

A hotter plug would be beneficial in an engine with really worn rings, if you idle a lot or drive like an old lady.

[ts johnson]

Thanks for the great info Blitz. I told the salesman that the denso website spec'd the ik20 and he insisted on the 16.

"I've sold these to alot of people with Subaru's and they work great!" he said. I'm GLAD I didn't throw em right in.

In researching [spark plugs] in the search area I started to feel like the iridium were't the answer to my fuel ecom prob. Do you have any suggestion as to what type of plug will give the 2.5 the best fuel economy??Thanksalot

[blitz]

Originally posted by ts johnson

Thanks for the great info Blitz. I told the salesman that the denso website spec'd the ik20 and he insisted on the 16.

"I've sold these to alot of people with Subaru's and they work great!" he said. I'm GLAD I didn't throw em right in.

In researching [spark plugs] in the search area I started to feel like the iridium were't the answer to my fuel ecom prob. Do you have any suggestion as to what type of plug will give the 2.5 the best fuel economy??Thanksalot

 

Always start with the recommended heat range and only switch if you have reason to believe that a hotter or colder plug would be of benefit for a specific reason.

 

NGK Iridium IX (#BKR6EIX-11) are way less expensive and will be more durable.

 

Great FAQ & tech tips at:

http://www.ngksparkplugs.com/products/cars_trucks_suvs/iridiumix.asp?nav=11420&country=US

 

About the only thing you can do to get better mileage is to keep the tires inflated and don't drive real fast. Both the AWD and the extremely over-square bore/stroke dimension (thermal loss) conspire against great mileage. It's doubtful that the plug change itself will have any measurable effect on fuel economy.

[ts johnson]

Good stuff Blitz!Thanks. What's real fast?. I usually average 75mph on the highway.Too much? As for themal loss...maybe if I back some more mouse poop and nutshells between the manifold and the block she'll hold the heat a little better.

I wish these cars had some sort of swith to deactivate the AWD when not needed! Thanks again!!

[blitz]

Originally posted by ts johnson

Good stuff Blitz!Thanks. What's real fast?. I usually average 75mph on the highway.Too much?

 

Drive smoothly and move with traffic, just stay out of the fast lane. Driving sporty is more fun, but it cost more money. If you can afford it, no prob.

 

I wish these cars had some sort of swith to deactivate the AWD when not needed! Thanks again!!

 

The auto-trans models do, but it doesn't de-couple any rotating mass from the system (rear axles, rear diff, driveshaft, and transfer-clutch all still rotate when the vehicle moves) so it doesn't really do a whole lot.

 

What I forgot to mention is that those heat-ranges I quoted are from more than plug manufacturer websites, they're actually from my '02 owners manual as well.