If your plugs have 35000 miles on them, they should be replaced along with coils & wires. This should be done regardless of your fuel consumption, as this is normal maintenance. While you are at it, I'm guessing your air filter and MAP should be serviced also.

 

Sounds about right. But aren't you assuming that is your car's sweet spot? In other words, you haven't tested mileage at 65 mph and 60 mph. My prediction is your mileages at 65 and 60 will be higher than your mileages at 75 and 70, with 60 mph being the highest.

Go ahead and test at 65 and 60 mph and you'll see that I'm right.

 

how much am i looking at for coils and spark plugs?

how much together and for each individually...i have a uncle who can get me them for what his dealership pays and he said its still few hundred.

how much did yous pay to replace?
not talking labor im putting them in with my dad.

 

4 Stock plugs and coils are about $200.

 

The only worthwhile way to increase mpg I believe is efficient driving behavior coz the price of modding is very unlikely to offset the money you could have spend on gas unless you will be keeping the car for a long time. Here is an article on mpg I find helpful at least for me:

http://www.everytime.cummins.com/***...Whitepaper.pdf

 

for spark plugs wires and coils?
brand new

 

Now you are mentioning wires too....OEM are about $60 ....so about $250 for all 3...

 

Can anyone give me a site where i can buy new plugs wires and coils?
I cant search on my iphone...will take wayy to long.

I was told from my uncle, he works at an acura dealership. He said for plugs and coils alone is roughly 300$

 

bumpppppp...anyone?
im trying to pay the cheapest i can

 

Here is a good deal....

http://atkinsrotary.com/store/catalo...t-p-17026.html

 

Mazdamotorsports.com

Seriously if you want to improve your gas mileage, you have to buy a new car. The RX-8 is not fuel efficient, it is what it is

 

thank you

no ****...but when my car only gets 11 mpg...thats not something im gonna leave alone...i obviously know the 8 doesnt get good gas milage...if you read the thread from the begining you would know that...my spark plugs, coils havent been changed in forever..

 

are the racing beat plugs alot better?

how do they differ from stock plugs?

 

They don't, its the same plug.

 

I think I got better mileage when I was catless... weird but true

 

But theyre racing plugs? they arnt different at all?
would yous recommend just getting stock over the rb?

would taking cats off stock exhaust sound like crap?
could be a temporary thing until i get an exhaust.

 

"This spark plug is NOT recommended for street use" is what it says for the racing NGK ones from Racing Beat. They're way too cold, won't do well in a daily driver.

No amount of mods is going to do miracles to your mpg... it's just something you have to live with. Have you measured what mpg you're getting yet?

 

Marc, not to be a pain, but I thought a week ago 3-30-10 you weren't sure about mileage...now it's 11mpg. Can you pls post up your last three fillup amts from your gas slips and the odometer mileage at each fillup? 11 mpg sound a tad low and I wonder how you suddenly are so sure...and I say that only because, well, take my word for it, it's happened a lot that people don't get their true mileage straight and get all worked up over the fact their RX-8 isn't an economy car. No one want to spend money fixing things that aren't broke, and I'm sure you don't either. So for any of us to give you the best advice, we need to know the real mpg backed up by your slips first.

 

okay first i filled up completly drove normally...i figured out that gas milage amount which was 10 then i filled it up half way nd reset it and figured it out again..over all i get between 10-11 miles..

i would post but i dont have how many miles i went on my gas tank...i think it was roughly 155-160...thats on a FULL tank.

now my most recent one which was 2-3 days ago i filled up and right now im alittle under a 1/4 tank and im at 190mpg...but i drove to and from the shore so all highway miles.

 

Here's the problem Marc. Trying to compute mileage based on full tanks and half tanks can't be done. Tanks and half tanks **are not** equal to a certain number of gallons. Gauges aren't accurate.

You need to go from a fixed mileage on your odometer. Write your mileage down, fill the tank to click off, drive until the next fill up, fill to click off, write down the mileage again. Repeat three times to get a reasonable average then divide the total miles driven (1st fill to last fill) by the total gas bought (total of three gas slips gallons) to get any mileage number that reflects reality and a sound mathematical calculation. And saying the city mileage sucks and the highway mileage is ok...well that's why you get the average...you need to, well, average these out.

BTW 190mpg isn't all that bad ... even on the highway

 

Marc, right now would be a good time to use, as NYGPS likes to say, some common sense.

 

well either way yous look at it my plugs and coils need to be replaced...i just filled up again and i reset my trip meter...ill tell yous this time

 

I'd actually suggest getting your 02 sensor and cat converter (leaning towards 02 sensor) checked/replaced first before anything, even if you don't have a cel, it might be a sign that either is failing or maybe has failed already...I'm in the same boat as you...getting 12city n 15 highway...compared to other rx8s that's pretty bad...n I'd say yours isn't normal either...I had a post about it but no1 cared to help so i'm jus researching it myself...its for my own good anyway.

I did everything people mentioned in your thread as far as improving mpg...from filter, cleaning maf, seafoam, even got bhr coils (wanted to upgrade 2 it regardless of the problem...its great!)...in the long run I increased 1-2mpg. So I kinda think its not something as simple as cleaning ur air filter and "whooop...there goes that 8-10mpg i'm missing"...but wut do i know?...i'm still learning so jus take my word as advice n not a definite thing...or not...up2 u

I'm gonna change my 02 sensor nxt week n let u know how it goes

 

That guy never calculated his mileage correctly, so he might not even have gotten 11 mpg.

 

Loki,

I'm totally stealing your signature!