Everything featured today was tested on Modified by KC’s Dynojet 424x. You may recognize this minivan because we used it in our Michelin’s X-Ice Xi3 winter tire test, running it against all-wheel drive trucks and cars in the snow (check it out here!). 

5 Trick Fixes for High Mileage Cars: Get Better power, Fuel Economy and Engine Longevity.

by Pablo Mazlumian

"So you guys are really going to test that thing?"

"Of course...we're from MotoIQ."

We often get asked what few, simple things could be changed on a used car to extend the life of the engine, or to improve overall power and fuel economy, as well as overall performance.  So here at MotoIQ, we’ve compiled a checklist of things to replace with universal products that will help most cars continue running tip-top.

In this first part of a two-part series, we'll talk about 5 things we can do to improve a car's engine performance and fuel economy, while helping the drivetrain spin a long life.


We’ll be swapping in new 02 sensors, sparkplugs and K&N air and oil filters that we got from Sparkplugs.com.  We’ll also be replacing the driveline fluids and with Royal Purple products.  The effects of this "tune-up", will be tested on the dyno and in the quarter mile! (surprised?)

We should mention that, even before our baseline testing, the MPV has been running fairly well.  Its 3.0-liter V6 engine has displayed a few hesitations during part-throttle operation here and there, but the minivan has been reliably getting us from point A to B in embarrassing fashion, and the tranny has had no apparent issues either.

For a proper test, you always need an up-do-date baseline.  We strapped the MPV to Modified by KC's Dynojet 424x, and this is what the front wheels turned—it's not a very pretty graph.  For a “200bhp” crank power rating, this 3.0-liter has probably seen better days.  With a quick assessment, it looks like the graphical dips could be caused by ignition retard due to detonation, or worn plugs, or the injestion of a small animal.

Given the fact we’re testing with 93 octane to eliminate the insufficient octane variable, we’re counting on worn plugs being the culprit of the dips we see in the graph.

This baseline setup also netted us 0-60mph in 9.0 seconds with a quarter-mile run of 16.9 seconds at 82.8 mph, which is surprisingly on par with what other publications tested when the MPV was first released—and we ran ours on a full tank of fuel, too.  See how the car fairs with its new tune-up in the quarter-mile on Page 7!



Our first order of business was installing new plugs.  If an engine can pump lots of air and fuel, then there's the potential for good performance.  But if the mixture isn't fully ignited, there's power left on the table.  Even worse, if the hesitations are bad, it not only will hurt overall fuel economy, but it'll leave your date wondering how pathetic the rest of her life will be if she stays with you.

Since our Mazda MPV has been periodically displaying subtle jerking at part-throttle, which we're assuming is from misfires, we're welcoming the new plugs.  It probably won't bring our girls back since hot babes don't dig nerdy dudes in a beige minivan.


Sparkplugs.com has about the best online pricing we’ve seen.  Having ordered several NGK Iridium plugs in both Projects E46 M3 and Project Supra, we decided to contact them again.  This time they had us try out their Pulstar PlasmaCore Pulse spark plugs.

While conventional plugs reportedly produce around 50 watts of peak power, a Pulstar plug gives off a whopping 5,000,000 watts—yes five million (insert Austin Powers pinky-lip shot).  How?  Unlike conventional plugs that dissipate and waste energy, a Pulstar PlasmaCore Pulse plug actually has a patented capacitor inside the core that stores the energy delivered by the ignition coil. 

Before the spark, this energy is released in a quick and powerful burst, forming an energy-dense plasma field that sensitizes the fuel mixture to ensure instant ignition.  With this faster burn, Pulstar reports quicker throttle response and higher average horsepower and torque.

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Monday, March 17, 2014 1:03 AM
I think putting clean fluid in the trans made the biggest difference of all. You still only did a partial purge of the fluid though, what I did with my truck when I installed a shift kit was put the fluid return line to a milk jug, overfill the trans by 2 quarts, then run the engine until the gallon milk jug was full. I did this 4 times and thought the 4th was a waste. I let the jugs sit a couple weeks and even the fourth jug, with its bright red fluid, still had sediment in the bottom of it. Case in point: the torque converter held about 8 quarts IIRC that doesn't come out by dropping the pan.

As for the dyno, does the car have a MAF? If so, I'd try cleaning it. I didn't see an AFR reading on the dyno, that may have indicated why the top end dies off too.
Monday, March 17, 2014 6:55 AM
I second the previous post about the MAF.

The engine cleaner is mostly alcohol, so if you can get some e85, just put a couple gallons in the fuel tank from time to time for a similar effect. A bit of warning though : be prepared to change the fuel filter too. it WILL clean you fuel system, and every gunk is going to that filter.

A little trick on the engine management system; they usually adapt themselves. Once you change spark plug, fuel, oil, filters and AFR sensors, reset them. Unplugging them for 10 minutes usually does the job (if you cant unplug the EMS, unplug the battery). Some require an OBD connexion for a reset, but most just reset once power is out long enough.

Finally, please MotoIQ, when did you start believing utter marketing BS ? A capacitor in a spark plug that multiplies power by a factor of 1000 and creates plasma ? Seriously ? Have you forgotten how ignition works, basic physics laws about energy conservation, and what a plasma is ?

Spark is created by "unplugging" a coil. This creates a huge voltage spike. That voltage spike is what creates the spark. Same as thunder, really. Put a capacitor there and it will fry. If it does not, it will convert back the high voltage spike to a regular voltage with more current, meaning no spark ...

So changing plugs, yes. Just get standard NGK coppers. Cheap and effective.
Monday, March 17, 2014 7:56 AM
I think the synthetic fluids were unnecessary, as is the high end oil filter. The difference in price between my CR-V's oil change (which uses standard oil and a Fram filter) and my 240SX (which uses full synthetic and a K&N filter because it's SR20 powered) is about $35-40 depending on what sales the LAPS runs. Will the synthetics reduce friction? Probably, but is it REALLY worth the added cost on an old car? Remember, once you go synthetic you can't go back! I used to run synthetic oil in my Integra and did not notice a difference in performance, not even after three years. Unless you're really thrashing on your engine, there is no need to splurge on the expensive synthetic fluids. After recently replacing the valve cover gasket on my CR-V (at 181,000 miles), the cams look absolutely perfect. No scuffing or wear and they are completely original. Just changing your oil on a regular basis will do the job...spend the extra money on beer instead!

Cleaning the IACV, MAF, and changing plugs and air filter are always helpful. Playing with ignition timing (for a distributor vehicle) can also bump your powerband a bit. And don't forget to check your tire pressures at every oil change!
Monday, March 17, 2014 10:29 AM
Playing with ignition timing will also melt plugs and pistons, do NOT touch the distributor cap unless you absolutely know what you are doing and have the tools to check if things are ok (i.e knock sensor, AFR and EGR sensors, logging capabilities).

Monday, March 17, 2014 11:49 AM
@ Crousti: Running standard NGK coppers strikes me as a really bad idea. In this article Pablo mentioned how changing the sparkplugs was a 2 hour ordeal and involved removing the top portion of the intake manifold. I just changed plugs on my sisters Maxima this weekend and that involved the same process but was more like a 5 hour job.

You really want to do that every oil change or two for cheapo coppers? Premium spark plugs have their place if nothing else for the increased service intervals.
Monday, March 17, 2014 12:11 PM
Fortunatley for me, 5 of the 6 cars I have owned have been 4-bangers making spark plug changes a snap. The 6th with a VQ35, I sold before having to change plugs :)

My family rocked the MPV for a long time growing up... great vehicle!
Monday, March 17, 2014 1:14 PM
I didnt see how many miles the MPV had. It looks pretty good for being a high milage van.

Our Odyssey has 150k+ on it and I would seriously consider doing the spark plugs, trans fluid and taking a look at the o2 sensors.

I dont have a problem running standard oil and filters though as the premuim is pretty harsh when you need to change the oil 5-6 times a year.
Mike Kojima
Mike Kojimalink
Monday, March 17, 2014 1:16 PM
Air gap capacitors in the primary circuit do work on ignition limited cars not sensitive to EMF. Tested it on the dyno many times. The chamber tends to carbon up turning it into a resistor in time and the effectiveness declines. It is not marketing hype but its not without drawbacks. I have proven this on the dyno several times.
Monday, March 17, 2014 7:24 PM
Mike, how long does the benefit tend to hang around? 20,000 miles would be one thing, but if it's only for a short while, then a standard high quality plug seems like a better idea financially.
Mike Kojima
Mike Kojimalink
Monday, March 17, 2014 11:52 PM
Option13, I think it depends on how much ignition demand the car has, the type of ignition and how hard it's driven.

Nology wires would not make any difference after about 10k miles and installing new ones would perk it back up.

I would be somewhat leery about putting air gap stuff in any late model OBDII car. Or if you start getting weird issues after installing air gap products put new normal stuff in. Nissans would wig out with these sorts of products.

I think they would be pretty cool on older cars as long as you realize that the life is limited.

These products usually work and it's not hype but like all things are are limitations.
Pablo Mazlumian
Pablo Mazlumianlink
Tuesday, March 18, 2014 12:20 PM
Thanks for reading, y'all.
@supercharged111: you bring some very valid points I will have to look into. I did notice the car took a lot less tranny fluid than anticipated. It also didn't occur to me about the MAF since so much of the testing I've done lately has been with MAP cars. Thanks again!

@Crousti: you bring up a valid point as well! I didn't think about resetting the ECU. I did this test on Project Supra as the first dyno test back in 2004 and the bone-stock Supra immediately went up from 263 to 275whp right on the dyno.
Regarding the plugs, while I am far from a plug expert and have primarily used NGK non-idirium cheapies on the Supra (and NGK iridiums on the M3, but also will be now on the supra as well), I did find this video showing the spark differences at least interesting between the two (NGK conventional vs Pulstar):

@8695beaters: I understand where you are coming from and for my real beater (an MX-3 I don't have anymore) I used the cheap Walmart Supertech stuff. An advantage of the synthetic fluids, however, is being able to change the oil half as much (although I still change the Supra's oil every 3-5k with synthetic fluids because I'm more particular with that car). So, one must take into account the added labor involved with using non-synthetic oils when weighing the overall benefits.

@Fly'n'Z: exactly! I was very disappointed to find out the intake mani would have to be removed. On the Supra and M3 it is literally a 15-20min job tops. On the flip side, the baby hauler this MPV replaced, which was a Renntech Stage3 M-B S600 V12 TT, had a 6hr spark plug job (that is over a grand if done at the dealer, no joke). So maybe the MPV isn't that bad after all, ;). Luckily it calls to be done every 100k or so on the S600. This MPV actually came from the guy that bought the S600 (no taxes to pay for me! :). And, given the fact he was replacing an Audi S6 V10 with the Benz, I figured he'd taken decent care of the MPV but who knows..

@spdraceut: I agree, and these cars were base $23k. I was pretty impressed with that, and they're even one of the better lookin' ones I think as well (although the sportier Sienna looks great, but $40+k new..).

@Protodad: I mistyped and mentioned 93k but that was what we bought it with. Car had around 106k during testing, and I'll have to update the article with the info.

@Mike Kojima, good to know about the long-term possible carbon build up for the plugs. Will have to keep an eye out. Luckily access to the front three for a quick check is right there.

Tuesday, March 18, 2014 1:49 PM
Great Read! I have 2008 Civic Si with over 140k on her (yes, I do a lot of driving) and found this article extremely helpful. Quick question though, I haven't changed my transmission fluid in quite a while (Maybe like 100k ago...)

I heard if you haven't changed it, you should not because its sets in your tranny? Is this true or is the shop giving me some bs?

Tuesday, March 18, 2014 3:02 PM
Thank you for this article. There are some good ideas both from the article itself and the comments. I'll keep all of this in mind when doing a tune up.
Tuesday, March 18, 2014 4:12 PM
Not convinced at all on the plug. I wrote a wall of text, so this is the short version: their website and claims are a bunch of lies. If you spark system is not up to the job, get one that is, using a bandaid is meh.

Basically they claim to have created a 20.000% efficiency system. Thermodynamists tend to say it is a no-no, if the spark system sends 50W to the spark plug, it will never get more, whatever you do. The gap setting tells the output is unchanged either (more power + same gap = melted plug). I think their system acts like a second coil, that ups voltage a lot (but shortens spark duration by as much). That would help a weak spark system, but retard timing. Which people may not see, as the burn goes better it compensates.

Honestly, their website is so full of utter BS, any scientist reading it would first laugh, then cry when realizing how low humanity has sunk. It has the usual "no real explanation but testimonies telling it works, and benefits "up to xx". I can't take that seriously, and you should not either.
Having a coil on spark ignition system (on a 1992 car, that started selling in 1986...), with a dwell adjustable time table in the ECU, i also can't see how it would do better than my coppers.

Anyway, talking about standard coppers. I didn't think about accessibility when i talked about them, my 4 pots is a 10-20 minutes job and we mostly have these in France. I can get 4 for the price of 1 iridium, and they last me 2-3 years, on a modified 100hp/l engine that has had its power output doubled (i love turbos). It does approx 5k miles a year , but from the moment the engine is hot, it gets thrashed. Maintenance ? 1 oil change a year. It has approx 140.000miles, and no rebuild. I changed the headgasket and the oil pump 20.000 miles ago, and that was it. Gearbox needs rebuilding every time i change the plugs though, i guess it does not like having twice more torque than stock.

Anyway, if the plugs can take that beating, i think they can last pretty long in a standard car.
Tuesday, March 18, 2014 4:39 PM
I don't buy the plugs either. If its hard to deal with (like most if not all transverse mount V6) then just put some platinum plugs on it and worry again in 2 years.

PS: If there are any admin or mods reading this, can some one help me figure out why I can't access the forums? I can see everything if I'm not logged in, but once I log in I can't even click on the sub forums or threads.
Tuesday, March 18, 2014 4:41 PM
^Scratch that. Was the forums mothballed and I didn't realize it?
Aaron LaBeau
Aaron LaBeaulink
Tuesday, March 18, 2014 4:52 PM
@Leon - yes the forums have been removed. When we upgraded our site software there was an issue migrating all the old posts. Given the extremely low usage of the forums and the high amount of time it would take to get them running again we have left it off since most people enjoy using the comment sections within the articles instead of traditional forum posts.
Wednesday, March 19, 2014 6:02 PM
From the manufacturers website:

According to them, a normal pulse lasts 30 μs at 50 W; they claim to store the voltage in a capacitor and release the energy in only 2 ns at 5 MW.

30e-6 s * 50 W = 1500e-6 J = 1.5 mJ
2e-9 s * 5e6 W = 10e-3 J = 10 mJ

So it's a fairly bold claim (that their system allows you to gain 8.5 mJ per spark that you would lose otherwise), but not a completely fanciful one. With the right setup, it's definitely possible to create a pulse with a very short duration and a high power.
Friday, March 28, 2014 3:32 PM
did the change the fuel filter?
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