Can spark plugs ALONE cause 5 MPG???

 

Not if your car is actually running normally. Maybe if your leading we'rent firing and you were running rich anyways.

 

i just found out my plugs were bad, especially a certain one...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/ngk-spark-plug-condition-341503/

along with running rich I think thats where our problems are. Ie 5mpg

 

Sure... easy

 

I second Icemark.... I change my plugs every 2500 Miles and by that time, when the new ones go in, you can actually feel the difference...... My gas mileage sucks cause of all the performance mods and my heavy foot, but on the old N/A GTU, after i changed the plugs that were in there since god knows when, i got about 6 mpg back!!

 

Even if the car is running the same as it is with new plugs (other than the bad milage)? As in, just as much pickup and such.

 

No, new plugs and plug wires would fix the poor mileage

 

If your plugs were bad enought to be causing the poor mileage, replacing the plugs and wires would give a NOTICEABLE improvement in snappyness to the motor

Start looking into clogged filters, low tire pressures, a dead body dragging on the rear subframe, etc.

 

low tire pressure can cause it????
They said put 32 punds of ait in the tires ryt???
I put 35 and it styll look flat!!!!