YACT: Gas mileage problem

[maximus maximus]

I have a mitubishi galant GTZ which I purchased last week. It has 90k miles on it and its a 2001 model.

The car runs fine, drives great and I love it so far... but there is one problem. Gas miles.

I take the highway to work everyday (20 miles each way) and drive at around 70 miles per hour. I have been getting about 10 miles per gallon. :Q

I was expecting close to 20. Now I noticed that the manual says use Premium gasoline, but I use normal. Could that make such a huge difference?

Anything else that I should be looking at? Any help from car gurus will be appreciated.

 

[vi edit]

If it wants premium, that could easily account for a couple MPG.

Other than that, do the standard stuff -

replace the fuel filter
replace/clean the air filter
maybe have the injectors cleaned

Keep in mind that you might be on the winter gas blend too, which usually gets you worse MPG than normal.

 

[radioouman]

The the air filter, spark plugs, basic tune-up items.
Check for trouble codes, maybe O2 sensor(s) is/are bad.

I don't know if octane could cause that or not. If the engine doesn't ping, you probably don't have to run premium in it.

 

[Aimster]

I would do the following

A) change the oil regardless of if u r getting good.bad gas mileage, You have no idea if the previous owner did it or not,
B) examine your air filter. If it is dirty then change it
C) I bet the fuel filter in that baby has never been changed, change it
D) spark plugs might need to be changed
E) use premium only
F) Get one of those small cans that clean your fuel injectors

Should solve your problems

 

[AgaBoogaBoo]

whoa, 10mpg... that would blow :Q

 

[jhayx7]

+Check Tire Pressure!

 

[maximus maximus]

Originally posted by: jhayx7
+Check Tire Pressure!

that looks ok.

 

[maximus maximus]

Originally posted by: Aimster
I would do the following

A) change the oil regardless of if u r getting good.bad gas mileage, You have no idea if the previous owner did it or not,
B) examine your air filter. If it is dirty then change it
C) I bet the fuel filter in that baby has never been changed, change it
D) spark plugs might need to be changed
E) use premium only
F) Get one of those small cans that clean your fuel injectors

Should solve your problems

Any idea about how much all this would cost?

Edit : Thanks for the list of things to check. I am sure it will work.

 

[Aimster]

Originally posted by: maximus maximus

Originally posted by: Aimster
I would do the following

A) change the oil regardless of if u r getting good.bad gas mileage, You have no idea if the previous owner did it or not,
B) examine your air filter. If it is dirty then change it
C) I bet the fuel filter in that baby has never been changed, change it
D) spark plugs might need to be changed
E) use premium only
F) Get one of those small cans that clean your fuel injectors

Should solve your problems

Any idea about how much all this would cost?

These are pretty much DIY , but if you can't do it.

A) $30
B) $15 - this one is easy DIY , just pop it open and pop it in!
C) This one is difficult. I always did it myself, but I think around $80?
D) This one could be difficult. I would say $100.
E)
F) $5 at the gas station, go inside and look on the shelf.

 

[Aimster]

& DO NOT GO TO JIFFY LUBE.

 

[vi edit]

Depends on if you can do any of it yourself.

An air filter is $6-$15 depending on brand and model.

Oil filter & 5 quarts of oil is around $12 depending on brands.

Fuel filter could be $15, it could be $50, and it could take 15 minutes to change, or it could take an hour or more.

Spark plugs are about $5 a piece and with a typical tranverse mount car can be a major PITA to replace.

Those little bottles of injector cleaners are only $2 or $3.

 

[BD2003]

Originally posted by: maximus maximus
I have a mitubishi galant GTZ which I purchased last week. It has 90k miles on it and its a 2001 model.

The car runs fine, drives great and I love it so far... but there is one problem. Gas miles.

I take the highway to work everyday (20 miles each way) and drive at around 70 miles per hour. I have been getting about 10 miles per gallon. :Q

I was expecting close to 20. Now I noticed that the manual says use Premium gasoline, but I use normal. Could that make such a huge difference?

Anything else that I should be looking at? Any help from car gurus will be appreciated.

They're just telling you that for nothing. Ignore it completely.

You also don't need air in your tires...just another suggestion.


But all joking aside, new air filter, tires properly inflated, wheels aligned. Throw a bottle of injector cleaner or seafoam in there. And USE PREMIUM.

 

[Toastedlightly]

Brakes stuck on? Jack up one side of the car (when it is in neutral, PLEASE block the other tires) and try to spin 'em. IF there is a lot of resistance, check out the brakes. Most likely not this. If the engine is high compression, you may be getting retarded due to the low grade fuel and may even need new spark plugs.

 

[OVerLoRDI]

Originally posted by: Aimster
& DO NOT GO TO JIFFY LUBE.

QFT

 

[Mermaidman]

Originally posted by: maximus maximus

Originally posted by: jhayx7
+Check Tire Pressure!

that looks ok.

Tire sidewalls vary in stiffness and just eyeballing a tire is not a good idea--use a gage!

Have you tried using premium and seeing what difference that makes? Other than MPG, how is the car's performance in terms of acceleration?