Roddimus Prime

so you think I should test a set of "silver's" in the plus4 style? These aren't available here in the states? I'm planning on including plugs in the kit also once I feel good about the plug I'm using.

Omron

if you call Bosch, it may be possible to locate a pair, but you can also inquire about the heat tolerences about the AMerican version which uses Platinum core, to be honest with you, I think these ones should be fine, because the 4 prongs are composed of a Yittrium/Nickel alloy, which by my understand of science should prove stable and safe at high operating temps. only if the platinum is in a alloy form will the bonds be unstable leaving it **** to buckling and breakin, the core is pure Platinum and from what i understand the plug is of a proper heat range to withstand extreme temps.



Rock on dude.

OldPro

I just this AM installed a set of Denso Iridium Power plugs in my '02 Pro LX, NA, minimum mods. I went from an apparent original set of NGK copper plugs (BKR5E) @ 33K miles to the Auto Zone supplied Iridium plugs. Made sure the set was at .040" gap & installed. Did NOT reset the ECU, and had no trouble. Let it warm up, and headed southbound. The idle is between 500 & 600 rpm, and purrs like a kitten! The pickup is exceptional, and the throttle response is fantastic!

According to the manufacturer's hype, it is supposed to improve acceleration (!), burn hotter, and deliver improved fuel economy. I will track that and post improvements or lack thereof.

We may have a winner here, Ladies & Gentlemen!

vielster

The difference you're probably noticing is just due to switching from old, used plugs to new plugs. It is improbably that a plug would give you any truely noticeable power changes. The temperature of the burn may improve fuel economy by providing more complete combustion, but would only possibly give less than 1HP change, if any. Just hope that the plugs don't cause any problems because of their hotter running temp.

OldPro

Based on my half-hour run yesterday, I noticed no increase in temperature in the run. I am keeping a close eye on this. More to follow.

Da P-Funk!

vielster is right - the biggest shift is from getting the old plugs out. If the performance stays strong right through 30K miles - then i would declare a superior plug.

Factor additonal cost of 'good' plugs vs just swapping out the $.99 cheapos at a greater rate (beacuse it is sooo easy ) say at 20K miles...

VS.

Any verified improved fuel economy (X cost of fuel/gal. times period of study i.e. 30K miles)

Bottom line: I don't expect any big advantage - so do whatever is best for you.

gino

Interesting thread throughout. FWIW, I pulled the stock plugs on my 03.5 P5 about 1500K ago (15,800K) and dropped in a set of Denso iridium IK16s--roughly 2 heat ranges colder than the NGKs that came with the car. The majority of my driving--about 85%--is 75-80+ and my colder plug choice was based on my experience with other 4-bangers of similar layout and output, and nearly identical driving patterns. BTW, plug checks show no abnormal burn patterns when cut clean under power.

While mileage formerly was in the 29+ range, it's been high 30s-31+ consistently since the changeover. Idle, throttle response and butt dyno "power" seem little affected, but the engine feels smoother when pushed to 6500+ under WOT, a strictly subjective opinion. The "fresh plug" argument is recognized and taken into consideration.

Having seen a number of arguments pro/con re: iridiums vs. copper, and in particular, the NGK "V" groove extended tips, I put a set of the latter in my wife's '03.5 ES with virtually the same mileage. She sees little change in overall mpg, with about 60% of her driving in town vs. highway.

Omron noted that the Bosch platinums provided improved mileage at road speeds, while in the suburban setting--around town--any increase in mileage was much less remarkable. This is consistent with the typical internal combustion engine under stop and start conditions as opposed to constant road speeds.

While the Bosch plugs in Omron's comparo suggest notable performance and mileage gains, I have found them ultimately to not perform well for me in three different modified engines, all of which were twin-cam fours burning premium fuel. This is not to say the Bosch platinum is not a quality plug; merely that I reverted to NGK in all instances when Bosch platinums failed to meet my performance expectations.

I'm pleased with the Densos and may drop a set into the ES for a comparo with the NGKs now in the car. If the mileage increases, based on the same driving patterns and habits, I can most definitely recommend the iridiums, which I'm inclined to do at this point.

Of course, I haven't tried the Bosch platinums in the P5 or the ES, but then, I would probably have to burn 89 or 91 octane fuel if I wanted to fully recreate Omron's tests. I currently burn 87 octane since I'm at 5280 feet, which drops the effective CR nearly a full point and allows the use of less expensive fuels without problems. I would find the expense of higher octane gas, as recommended by Omron, to be a "pay your money and take your choice" option that I'm not disposed to try.

Da P-Funk!

*Why* would i run the higher octane/more $$$ ($$CAD ) to save a small ($) fuel amount?

If the timing would advance to take advantage of the Bosch plugs - yeah! I would do it!

Does filling with 94 octane and then clearing the ECU (disconnect and dance on the brake) give me a noticable jump in power? Does the ECU run a more advanced timing because the knocking doesn't occur when it did before?

Oh Boy!Oh Boy!Oh Boy!Oh Boy!Oh Boy!

uclaP5

a key factor i didnt see in your description is which car was the lead car. your description indicated to me that the ngk car was always in front, and the bosch in the back. this would give the car in the back an advantage due to drafting, and would show an increase in milage. Nullifying all your findings.

if i am wrong please correct me, but you did not make it explicitly clear.

Phantom Cruiser

he said this:

So the playing field was pretty much equal. because both cars were going the same direction at the same time. we were driving side by side most of them on the 3 lane road. hahah no slip stream stunts.

Omron

I am not sure what the Computer (ECU) protocols are, nore could i explain what exactly is giving off this effect but it seems to only last for 10 km or so, but if you have a Sunoco near you and you can try it for a little while do it. The harm to your engine is minimal but if you feel the car is Knocking cut it out. The timings may run more advanced or it may be something else, Its only something we notice or felt in the driving. We are waiting on a computer interface unit to hook up to the ECU to monitor these values. Then we can see for sure whats going on.

Cheers

Omron

Thank you Phantom for the quote, haha I thought I said that in there somewhere when I was reading the question...

it was pretty much side by side driving most of the way. I think the closest we ever got to each other was 25 meters and that was when the highway for the last 30km turned into a 2 lane road. We didn't want todo the side by side thing cause those damn mack trucks were starting to hit us with a bit of that highbeam rage.

We are going to do another trial to meet up with those girls in london again so we are going to try it again, both plugs have now 12,000 km on them, which is a good breaking in for both. I think with my friends car running the NGKs with slightly less km on them. But after a visual inspection, we will proceed.

Omron

Well put Gino, and very true, my only reason for using Sunoco is my wonderful discount card for higher octane grades. I wouldn't expect the average man to start shelling out dollars at the pump just for a grade of gas that slightly has a less amount of crap like sulfer in it. I mean a 10 cent a litre adds up quickly. But since it was an offical test I did want to go with what the manual says.

And the for future of my tests 91 or higher will be the standard for all my tests, Straight from Sunoco

The schedual dyno tests in the near future will settle everything, but I am getting alot of people asking me if the IX irridium was the best choice is there another NGK irridum plug out there that I should think about including?

OldPro

At Longgggg last I'm back on with an update of the earlier comments on the 0.4 Denso Iridium plugs. I made a 6,000-plus mile trip of the US (even came through B'ham, Matty!). My mileage was not much better than running copper plugs. On the wide open interstates I DID push the speed up to 115, put had to bring it back down due to the trucks on the road. And it did feel like there was more to give! My original comments of better acceleration, etc. Was based on the old plug/new plug switch. Highest mileage was 30 mpg, worst was 24, average was 26. So much for grand and glorious raves about iridium plugs.