All things that can cause bad gas mileage

[ViperRider]

I want to make a list of ALL things that could cause a drop in gas mileage.

1. Under-inflated tires.
2. Bad oxygen sensors.
3. Bad EGR valve
4. Clogged catalytic converter
5. Bad PCV valve
6. Extra weight (sound systems, etc)
7. Carbon buildup in intake.
8. Dirty fuel filter
9. Old oil
10. Dirty injectors
11. Old plugs/wires
12. Dirty air filter
13. Bad gas cap/leak (evaporation)
14. Bad spark plugs
15. Bad air temp sensor

Anything else?

[techsan23]

Re: All things that can cause bad gas mileage

leaking fuel injectors, evaporation if your tank isnt sealed or bad gas cap. dirty spark plugs, and bad air temp sensor; just off the top of my head.

[Blacmaro96]

Re: All things that can cause bad gas mileage

-unecessary crap like sound systems
-Bodykits
-Carbon buildup in intake.
-dirty fuel filter
-old oil
-dirty injectors
-old plugs/wires
-dirty air filter

[Taheen]

Re: All things that can cause bad gas mileage

Too many cylinders ;)

[Smoke Panther]

Re: All things that can cause bad gas mileage

I want to know ALL things that could cause a drop in gas mileage.

1. Under-inflated tires.
2. Bad oxygen sensors.
3. Bad EGR valve
4. Clogged catalytic converter
5. Bad PCV valve

Anything else?

6. You

[ViperRider]

Re: All things that can cause bad gas mileage

6. You

I don't see how, I only weigh about 190 and keep the revs below 2500 rpms. And I get 18 MPG city. But yea a lead foot driver could cause bad gas mileage, but I'm not talking about that though, only things ON the car that can cause bad MPG. Thanks for the input though. :tup:

[Kal-El]

Re: All things that can cause bad gas mileage

Bad oxygen sensors and Bad EGR valve what if u dont a sens light on these will they still go bad i thought if they do u trigger a code

[Slave One]

Re: All things that can cause bad gas mileage

Bad oxygen sensors and Bad EGR valve what if u dont a sens light on these will they still go bad i thought if they do u trigger a code

good question, wondering the same thing...

[Kal-El]

Re: All things that can cause bad gas mileage

anyone?

[Blacmaro96]

Re: All things that can cause bad gas mileage

Yes, it will affect even if not sending a light. think of it this way, if it does read a lean or fich mixture and such, when new, it will correct it exactly to what it needs to be, but when old, and with carbon and exhaust gasses covering the probe, it wont react as quickly, and wont give as precise an exact amount that you need, so most likely it will dump more fuel in, especially if it reads lean when actually your mixture is fine. The only time it comes on is when the sensor is faulting (going bad) not reading anything, or reading that your mixture is way off for a period of time ( say like 30 second). Unless the mixture is waaayyy off, either lean or rich for an amount of time, it wont send the light on. It can become way off for a split second ( idle to WOT) but our cars amount of air and fuel we get, is pretty precise as it is with the other sensors like IAT, MAF,etc. so the oxygen sensor usually doesnt read way off mitxures for a period of time, but when it does, you will get a light. So yes change your oxygen sensors for a more precise reading.

[Kal-El]

Re: All things that can cause bad gas mileage

cool thanks for the info but what about the egr?

[RyanAndyBob]

Re: All things that can cause bad gas mileage

Agressive driving.... lol

[PontiFireFalcon]

Re: All things that can cause bad gas mileage

I don't see how, I only weigh about 190 and keep the revs below 2500 rpms. And I get 18 MPG city. But yea a lead foot driver could cause bad gas mileage, but I'm not talking about that though, only things ON the car that can cause bad MPG. Thanks for the input though. :tup:

I weigh 180. I try to keep it below 2000. Do think I should step it up to 2500?

Also, getting a big Trans Am wing, decreases fuel efficiency.

[99pewterv6]

Re: All things that can cause bad gas mileage

I didn't think the EGR would cause a noticeable change in mileage. Some people just remove them without any adverse effects.

[Firebirdkid96]

Re: All things that can cause bad gas mileage

Slipping Tranny creates excess power from engine that never sees the rear wheels...