I was thinking of changing my spark plugs because I am getting horrible gas mileage. I drove all highway for 200 miles and got 19mpg with the AC off. I dont ddrive hard at all. I baby my car like no other. Hopefully, a spark plug change will give me some better gas mileage.

My questions are...
What kind of spark plugs do we have? Should I replace them with the same kind? Should I change them to something else? If yes, what kind? What else do I have to change?

Thanks
Rosh

 

The stock plugs are N.G.K. I would replace them with the same one's unless you have performance mods, or money to burn then get Denso's. I have the Denso's and honestly notice no performance difference over the stock plugs even mated with intake and headers. The install is very easy as well.

 

Depending on your mileage, you might want to check on your O2 sensor. Sometimes when those things gets bad or dirty, it will result in bad gas mileage.

 

You dont need a different kind of spark plug. look in to changeing the wires or fule pressure regulater

 

Maybe you have dirty fuel injectors?

 

Um no....we have a distributorless ignition. No standard plugs wires.

Oh and they run $40 a piece ($240)

Couple of cheap things to try first:

1) Check your air filter - replace if necessary
2) Run a bottle of fuel injector cleaner through the car

 

Thanks for the info. Where are the O2 sensors? Are they easy to get to/replace? Expensive?

Another reason why I wanted to replace my plugs is when I take it up to around 2500-3000 rpm's, my engine gargles and is not consistant with power. It is especially noticable when the temp outside is 70 or below because you can hear more noise. I use 93 gas all the time. I have tried every gas station around and it still does it. I thought it was normal but when I got a TL loaner, the car was quiet throughout the rpm range.

Rosh

 

Ok, I just went to NGK's website and they said the TL needs Laser Platinum spark plugs. I was also looking at the VX platinum. Can we use these? They are supposedly better. They also have Iridium Plugs which are supposed to be the best. Should I try one of these or just stick to the regular platinums.


Rosh

 

How many miles do you have on your vehicle? The OEM sparks are supposed to last 100,000 miles.

 

O2 sensor is located in your exhaust manifold. If you jack up the car, you will see it. But from what you mentioned above, it might not be the problem, I still say it sound like the injectors.

 

I know its soon but it might help to change them. I have around 53k miles so I'm not losing out that much...

Rosh

 

check the gap on the spark plug. it may help to switch them, but why throw away $$ that you can spend towards really fixing the problem. check the cheap stuff first like the air filter before just going buck wild and replacing everything

get a bottle of BG 44K and run it through...to help your fuel system. may need to do it around an oil change interval just to get the crap it will dislodge out of your engine quickly.

not sure what you mean by gurgling? if it's not enough fuel, check the injectors.

 

check the gap on the spark plug. it may help to switch them, but why throw away $$ that you can spend towards really fixing the problem. check the cheap stuff first like the air filter before just going buck wild and replacing everything

get a bottle of BG 44K and run it through...to help your fuel system. may need to do it around an oil change interval just to get the crap it will dislodge out of your engine quickly.

not sure what you mean by gurgling? if it's not enough fuel, check the injectors.

 

I agree with NSXNEXT's and medic's posts (both of them). Do the cheap stuff first. It's amazing what a bottle of fuel injector cleaner can do. The crappy mileage happened to me a couple months ago @ 16K miles! One bottle of Valvoline synthetic injector cleaner and all is well again.

Also, rev that baby every once in awhile. Get the carbon out!

$.02