ABracy

I want to change my spark plugs. I have 95,000 miles on the current plugs. I went to the store to buy a set and the selecter stated that Autolite regular were OEM. So I found Autolite Platinum plugs for Scion XB 2004 and the gap was .044. I was browsing the internet and a site stated that the gap was .077-.079. Now I'm really confused so I called Toyota. The parts dept. guy told me that I should not used any other plug but theirs because it will damage the vehicle and further more, they did not use autolite plugs. Does anyone know the correct gap setting and can I use the plugs that I purchased?

dugzilla

You can use whatever plugs you want, it's not going to hurt the car.

Do a search, there are lots of thread on which sparkplug and what gap to run.

Factory is .044, but there is debate on whether or not you get better mileage if you open the gap a bit.

ABracy

Thanks!

XbbbbBox

I find the XB wears plugs more than any other vehicle I have had.
Last time I used NGK Platinum - $2.55 each from Rock Auto.com

NGK Part # 7090 {GP-Series #BKR5EGP}
{.032 gap}

I have had very good results with these plugs - last lot longer than standard plugs and reasonable price.

eric_04scion

i just put the bosch prolite platinum 4's on my 04 scion xa and put the gap at .077 and noticed a better start and better gas mileage. havent had anything go wrong yet.

dirtyh2odog

I am using these same plugs and have great results as well...and for the price and effort it takes to change out the plugs, give them a shot and if you don't like it you are only out $10...but, I think you will like it...I had to adjust my gap down to .032 as they were set to about .042 out of the box, so make sure you check the gap- as you always should.

dz302

Just an interesting point I noticed while browsing the forum: Apparently the TC's have Denso iridium plugs from the factory.

Guess we couldn't get that lucky eh?

Seriously though: Scion states to change the plugs at 30k intervals. Is this by and large what folks are doing?

hotbox05

ngk iridium IK 9

HeathenBrewing

I was curious as to the condition of my plugs @ 16K mi. Since I took the time and pulled them out, I figured why reinstall the old ones? Of course the old plugs looked almost new, but @ $8.00, they were too cheap not to replace. Replace > Reuse IMO.

I put in 4 new OEM Denso K16R–U.

ABracy

Does anyone know exactly how the spark plug works in terms of the gap? I mean if you open the gap more what actually happens? If you close it what results will you get?

HeathenBrewing

A narrow gap may give too small and weak a spark to effectively ignite the fuel-air mixture, while a gap which is too wide may be too wide for a spark to fire at all. Either way, a spark which only intermittently fails to ignite the fuel-air mixture may not be noticeable directly, but will show up as a reduction in the engine's power and fuel efficiency.

As the plug ages and the metal of the tip erodes, the gap will tend to widen; therefore experienced mechanics often set the gap on a set of new plugs at the engine manufacturer's minimum recommended gap rather than in the center of the specified acceptable range, to ensure longer life between plug changes. On the other hand, since a larger gap gives a "hotter" or "fatter" spark and more reliable ignition of the fuel-air mixture, and since a new plug with sharp edges on the center electrode will spark more reliably than an older, eroded plug, experienced mechanics also realize that the maximum gap specified by the engine manufacturer is the largest which will spark reliably even with old plugs and will in fact be a bit narrower than necessary to ensure sparking with new plugs; therefore, it is possible to set the plugs to an extremely wide gap for more reliable ignition in high performance applications, at the cost of having to replace and/or regap the plugs much more frequently, as soon as the tip begins to erode.

ABracy

Cool. Thanks. You put that very well!

jallamas

Nice info!


Thanks



John

Reiji_Dorifuta

Hmm... take the minimal gap and add .010, maybe?

Sciond

at 28,000 miles I put in the Denso Irridiums...and never looked back..I have 72,XXX on the box now... I should go 50,000 more miles or so before I touch them again