I've recently purchased a '93 Rx7 stock to the bone. It's automatic, but the problem is its mpg. I have paid attention to how much gas I consume, and concluded that I get around 10/11 miles per gallon. A friend of mine suggested that I change the spark plugs(i've already changed engine oil). I hear NGK spark plugs are good for 13Bs, but I don't know which ones. Please help!

 

get ngk 7s and 9s .. i dont think you need the platinums

 

i see people running all 9's. whats up with that?

 

https://www.rx7club.com/showthread.p...ht=spark+plugs

 

so should I get 2 7s and 2 9s? Is that how it works, or just 7s?

 

if your car is stock, then yes, get 2 7's and 2 9's.

 

I would still run all 9s because they are a colder plug, and i feel they make the car run much better under boost.

 

should I get EQs or EQPs?
And do they improve the mileage issue?

 

EQP's are the platnum ones. They last longer but provide a slightly weaker spark than the EQ's. For a stock car just get the cheapest (the EQ's).

If your plugs are shot, then yes, you'll get awful gas mileage.

 

thanks for the info. Should i just replace my wires while at it, or do they not make much difference?

 

jolie im in the same boat as you .. i just been reading up .. and i decided to go with ngk 7s and 9s .. cause im running pretty much stock .. and i think while im down there changing the spark plugs why not change the wires as well .. you can get some ngk wire plugs from gothamracing which will cost you bout 45 bucks .. i however am going with taylor spiro pro wires

http://www.scuderiaciriani.com/rx7/i...stall.html#SPA

 

Hey, thanks a lot for the site.
I ended up buying some shitty wire package from NGK. But anywho, site you posted should come real handy. It looks quite difficult, but i should give it a try.

 

Many people use the "shitty" NGK's since they do the same job as all the rest.

 

Yep, shitty NGK wires here, too. My car runs great with them. They fit just like the originals.

Sonny

 

http://home.covad.net/~f2racer/plugs.../plugwires.htm

This might help too.

 

bad O2 sensor can contribute to poor gas mileage too.

 

what would happen if you unplugged your o2 sensor? just a hypothetical question .. not something im gonna do to test out myself .. but what would it do to the car?

 

besides an exhaust leak.... computer would go on a fritz!

 

How do I check whether I have bad o2 sensor.
And what do you guys get mileage-wise with your FD?

 

My car is stock except for the downpipe, and I'm getting 15-18 mpg on average, with the car seeing mixed city / highway driving. Best MPG ever was ~20mpg, driving a 250-mile roundtrip. Worst was ~13mpg autocrossing at a double-practice weekend (6-12 runs each day).

I've been told that cleaning the fuel injectors can improve mileage by 2-3 mpg. Also change your fuel filter if you haven't already.

-s-

 

Cleaned injectors + new fuel filter + new plugs/wires + new O2 sensor = 22.4 mpg (mixed driving) for me

Sonny

 

How can you tell if your o2 is going bad???