Still testing mileage aspect....I'm still trying to get some data that doesn't include a 15-20+ MPH head or cross wind- we've been in a wind advisory seems like every day that I've driven the truck.

Even with the wind, my worst mileage was 20.2 MPG on the highway.

anybody have any updates on mileage with these things and is there any electrical interferance with like the radio or anything like that?...im still on the fence

Nothing new to report. I haven't looked at the forecast this week, but HOPEFULLY the wind will die down. Either way, the truck is much more responsive and fun to drive, and I'd say my overall mileage is up. Up 15%, I don't think so, but up .5 to 1mpg maybe.

Fuel trims did go about 1-2% leaner. Mine were pig rich with the stock tune, so it shouldn't adversely affect anyone IMHO.

I haven't heard any radio noise, but all I have is the stock radio.

When I go to do our TB, I plan on building them to be honset. I'd rather build them due to the cost- especially if the MPG don't significantly increasee when I get some good data.

To give you an idea how much a cross/head wind effects our fueling (drag produced on the truck), here's a doc w/ some screenies to look at. The top number is the MAF hz, the number in the cell is the counts that the cell was hit. Same drive, just one had 15-27mph wind, the other had 8mph wind.

Notice how the counts are further up the Hz range, and there's more counts up higher in the first screen shot. This means the engine was working harder to maintain the same MPH. It also means it was burning more fuel to maintain the same speed.

http://www.fileden.com/files/2010/5/3/2 ... arison.doc

Here's my data/spreadsheet so far.....

http://www.fileden.com/files/2010/5/3/2 ... dsheet.xls

I'm ready to make an initial verdict since I've gotten 3 consecutive days of zero to little wind driving.

First and foremost, did they live up to the 15% mileaage claim? In my case, no. It could be due to the wind conditions during the testing, the combo of flat lands and river hills on the test drive, humidity, the plugs having 60k+ on them, or the fact that I'm tuned, and it may not help as much as a vehicle that is un tuned.

Did they increase my mileage? YES. As I stated previously, my worst tank was 20.2, with higher mph cross/head winds. Prior to the COP's, my mileage in the same conditions would have been low to upper 19's. My last 2 fillups netted 22.5 and 23mpg. Not the increase I hoped for, but as long as I keep a truck, and as many miles as I put on one, they will more than pay for themselves through the trucks life.

Also of importance- did it make a noticeable difference in feel, and more fun to drive? Definately. On ramps are a LOT more fun, and the few times I hit PE/WOT, it really pulled hard. Downshifts under heavy throttle hit more like a sledge.....well, as much as a 3.5 can hit LOL.

Points of interest:

KR- average amount of KR, and counts of KR went down. This can also be attributed to humidity- the more humid it is, the less KR you'll see. Even so, both average and counts were down.

LTFT/STFT- in my case, STFT since I've tuned out LTFT because in my opinion they tend to collect 'junk'. Regardless, I went from STFT averaging -.5 to -1.5, up to +.2 to +1.6 or so. IMHO, I'm burning the same fuel, more effecectively (hence the PCM adding .2 to 1.6% fuel to compensate for a lean condition.

ETC% vs Main Spark HO- in comparisons to previous scans, the ETC % went down, meaning it took less throttle to acheive the same amount of power in that particular cell. Unfortuneately, I don't have any weather info to match up prior scans to make it an even comparison (as in comparing 2 seperate days driving from Lincoln to Omaha with the wind out of the NE with a 15mph average and 25mph gust).

At the end of the day, are they worth the $80? If you plan on driving your truck into the ground, or are in search of every last bit of MPG and power, sure. I'd try and build them myself first, though.

I am curious to see what happens when I freshen plugs up, since my Densos have about 60k on them.

excellent review! nice to see the numbers not just a "yeah butt dyno says it works" Im still thinking of building my own. north of the border they go for 95+ shipping

great write up and thanks for staying on it like you did...jcwhitney has em on sale right now for 79 and if you enter jcw75 you get free shipping

That's awesome! I could always use better fuel economy. I average 30k miles per year so they would pay for themselves in the first year. I'm gonna try to build my own and see if my economy improves.

BTW, my Densos lasted 94k miles and had worn to nearly .25" gap and still idled smoother than the new Delco Ir plugs that replaced them. :shocked:

94k mile Denso Ir plug on left - New .044" Delco Ir plug on the right


Needless to say, I am again running Denso Ir plugs

Thanks for the thorough review!

Thanks fellas! Glad I could help!

Holy crap- that's good to know. I was kicking around getting the Delco IR's just because of availibility and to save a few bucks, but probably not now. Were the Denso's spooned on the end of the ground strap like that from the factory? I honestly don't recall what mine looked like.

The Densos have the U-Groove



Mine wore down that way.

please keep us in the loop, I'd like to build my own as well

Let me know what/how it goes- I'm curious too!

In the (hopefully) near future I'm going build a set for our TB using some fine strand wire and some connectors from hopefully Advance.....found some on ebay, but I'd rather go local. Figure I'll just reuse the boots since they have less than 10k on them. Might be able to use some leftover amp power wire. Won't take much wire, that's for sure!

Only problem is, the wife drives the TB, and doesn't track mileage "because that's your job".......I'm sorry I'm not there to fill it up and do a simple mathematical computation for you and reset the damn trip odometers! Kind of hard to track it and do 'my job' when you won't help me to do it woman! I'm done with my rant for now .

Have her write down the odometer and trip mileage at each fill-up. That is what I tell my wife to do. That is her job so I can do my job!

Thanks Steve- I'll give that a shot!

Are these still performing as noted above? I know, not that much more time. But figured I would trey a set if still proven to be reliable.

I'm waiting on spark plug terminals. They were backordered but should ship out this week. Then I will be able to build my own once I receive them

Still performing just fine. I'm on to another project now to increase mileage and power.

DB- where did you order your terminals from? That might be a good project for me to try on our Trailblazer while I'm recouping from ACL reconstruction.

I ordered the Taylor 44399 180° (straight) spark plug terminal 50 pack from Jegs because I ordered new battery through them.

http://www.jegs.com/i/Taylor/895/44399/10002/-1


Summit has them in stock: http://www.summitracing.com/parts/TAY-44399/

what is your next project Hawk?

DB- THANKS!

Zeuce- 3" MAF tube- HERE

nice that is def something to consider doing!

THANKS!

I gave up laying in bed at night pondering such things as world peace, cures for cancer, and why there isn't mouse flavored cat food and cat flavored dog food.

Thinking about what else I can mod for more power and economy just comes easier .

Question has anyone installed a set on a 2007 or later 3.7? I did mine today and found I had to do some modifications to them.

What modifications you have to do?