very poor gas mileage?
 

i am getting very poor gas mileage in my 1994 mazda protege. i am averaging about 350 or less km's per tank. a few months ago, i have gone up to 420km/tank and since then, i can never get more than 350km/tank. i am filling it with 87 chevron. this car is driven in the city and rarely in stop and go rush hour traffic. i have read that this car has very good gas mileage but i don't know what is wrong with mine. any advice?

Do a basic tuneup.
-change oil / filter
-change spark plugs
-change fuel filter
-change air filter
-get your timing checked.

that should help.

I've noticed with the colder weather i've lost fuel mileage as well.

me too... only getting like 350

simple solution. STOP GETTING STUCK IN THE FUCKING SNOW. that kills alot of gas.

gas stations add stuff to gas in winter times and that makes the gas have less milage

yeah that's a good list, I would also like to add one more thing..

-fuel system cleaning

you can get it done at any quick lube shop(EZ Lube, Mr.Lube, etc) Canadian Tire, Walmart or any other shops. It made a quite bit of difference for me, it will cost you around $100.

That year Protege is not all that great on gas (my bro has one, and it's worse on gas than my 4x4 Suzuki Sidekick).

Also...it's winter. Your car will use more gas warming up than it would if it's 20C outside. (My g/f's Honda Fit's gas mileage goes down the shitter in the winter...she's in Kamloops)...my Zuki runs rich as hell for the first few minutes of starting up in -40C and idles at 2,000+ RPM 'till it's warmed up...trust me, that shit doesn't do anything good for your gas mileage haha. Spinning your tires on ice/snow will also use more gas.

Chances are even if you didn't do anything to your car, gas mileage would improve in the spring.

One other thing to get checked out, is the O2 sensor.

its the cold weather

check tire pressure

its because of morning starts, cold temp, so ect sensor(i think, i forgot what it is)tells the ecu that the engine is cold, computer dumps more fuel to heat up the engine but since the temp. is cold it takes time to heat up....you can notice it in the rpm gauge, mine is 1500-2000 rpm(i can be wrong tho, any corrections will be appreciated)......+ getting stuck in the snow + showing off fart can by reving it...hahahaha

Do not worry too much about a slight bump at your fuel bills compared to warmer days.

your car needs to burn more fuel to run your heater and to heat up the cold parts.

I would say my car uses 10%more fuel in Winter ...

yeah, a bad O2 or A/F (air flow) sensor kills your gas mileage

but usually, if either sensors are bad, your engine check light should pop up.

my brand new 2009 XRS just finished a tank, i got 350km on it before the light came on and i literally drove 90% city well below speed limit on most days in this weather..that's pretty shitty
My parents 2008 RAV has been filling up every 4 days on city driving too...running about the same mileage.

The heater uses more fuel to run than A/C too.

True dat!!

what about tire pressure? do you guys keep it below or above normal PSI level during snow?

Ummm, not always. A bad A/F sensor might give a CEL, but a bad O2 sensor usually will not. I know older cars won't, and i am pretty sure newer car's don't either.

Ummm, no it doesn't. A/C uses more fuel because of the extra belt that is connected to the motor to run the A/C pump.
The heater has a fan that is taking the heat from the coolant that is circulated through the heater core.

dumping more fuels will NOT heat up the engine more, it's the opposite actually; the additional fuel is to heat up the catalyst converter to working temperature more quickly for lower emission.

and that is totally incorrect.

damn it, do any of you know how a heating system work in a car?

A bad 02 sensor will pop a CEL. :)

And it's the first time I'm hearing that turning on the heating system will use more fuel to run than A/C....lol...sigh...

A heater doesn't use more gas... the coolant in the car acts as the heat source. and that sorta gets hot by the engine. so yea.

so does it mean it uses the same amount of fuel while idling without the heater turned on compared to when the heater is NOT on??

I just wanted to make things clear guys...

^ Yes. Clear?

Sorry my bad. On OBD1 cars, a bad O2 sensor will not pop a CEL.
OBD2 cars will, especally those ricers that run a test pipe because the signal from the O2 sensor is out of normal operating range, hence the need for those O2 sims.

I already said, the hot coolant runs through the heater core where there is an electric fan that blows are though it and out comes heated air.

Idling without the heater turned on and when the heater is NOT on is the same friggen thing. The heater fan is OFF.

Noobs... :haha: