Help with low gas mileage

[kevintomb]

I have an 03 Matrix.....base model with automatic and just front wheel drive. MY issue is I get nowhere near the window sticker numbers and this is driven by my fiance and she DOESNT race or go fast or anything like that EVER. EVERY other car weve owned weve gotten VERY close to the actual numbers posted on the sticker. And when we drive my 03 camry we both get very close to the same mileage. Weve enen tried trading our cars for several weeks to see if its just her trip or her driving and we still get VERY similar numbers

Overall we average ONLY about 26MPG for our driving and that is BAD. My camry which weighs 500lbs more and has a much larger 2.4 litre engine gets almost identical mileage on our around town and mixed driving. On highway driving our matrix gets about 31MPG, my Camry about 30. My question is, if we are NOT driving crazy and have even tried trading cars to eliminate the idea that it is her driving or her trip and concluded that we BOTH get very similar mileage, is WHY IS IT SO LOW??....Its a 2700 lb car with a small 4 cylinder. Remember we DONT drive it sporty or fast or use the air. AND MY OTHER HEAVIER CAR gets similar mileage.....so what is up with our matrix

by the way...it has only 52,000 miles and tires are inflated properly and it runs flawlessly and is very well maintained

[PA Firefighter]

Very strange indeed. Mine's auto as well, I have a lead foot, and I get bette mileage then you do. I'm running about 33ish highway and 28 city. I drive equally on both, so that puts my average around 30 1/2. I do know that auto cars generally get less MPG then manual cars, and manual MPG is what goes on the sticker most of the time.

[Smar969905]

the automatic transmission uses up some of the available power from the motor. the 4 cylinder motors that go into these cars are small, and dont have much power to start with, so it takes more effort for them to push the automatic instead of the manual. this in turn translates out to lower gas mileage.

automatics have improved over the years, and in some cars, the automatic is only about 1 or 2 mpg lower, but the automatic is still worse on fuel economy.

if it makes you feel any better, i have a manual in my car, and i am only getting around 27-28. dont worry about the fact that it is the xrs and i am heavy with my right foot though.

[757Scubasteve07]

A bad oxygen sensor can result in poor mileage also, just throwing that out there. But yes automatic transmissions use a lot more power from the engine and thus result in worse mileage.

[Georgenfla]

Could also be a dirty mass air flow sensor. Also, you may have a sticky brake caliper that is not releasing completely. Check, after driving your car, to see if one brake caliper is hotter than the other. You can do this buy asking a mechanic to shoot your brake rotors with his laser powered temperature guage. This has to be done right after you've driven the car for a number of miles...if your caliper is hung up, that caliper will read way hotter than the other caliper. This is just a possibility for crappy fuel mileage.

[MrJones]

i get like 26 mpg .. friggin sucks. i thought id get more, but im usually doing 55-65 on the way home and i have a lead foot. glad i didnt get the 2zz with the way the price of gas is going

[Smar969905]

Originally Posted by saybakgung

glad i didnt get the 2zz with the way the price of gas is going

i have the 2zz and i have a lead foot. on my last tank of gas, i got 27 mpg.

[MrJones]

Originally Posted by Smar969905

i have the 2zz and i have a lead foot. on my last tank of gas, i got 27 mpg.

damnit. i need to reset my ecu.

[Smar969905]

im running all stock on it right now (unless there was something done by a previous owner). that 27 mpg average also included about 120 miles of freeway driving, however about half of that was in slow & go traffic.

[D Rock]

While the milage you are talking about is probably on the low end of the scale, I don't know that it is that unusual. As others have said, check mass flow and oxygen sensors.

I am admittedly fortunate, as my XRS gets around 27 mpg unless I really beat on it.

DR

[wiccanferret]

What all have you done maintenance wise?

[kevintomb]

Originally Posted by Smar969905

the automatic transmission uses up some of the available power from the motor. the 4 cylinder motors that go into these cars are small, and dont have much power to start with, so it takes more effort for them to push the automatic instead of the manual. this in turn translates out to lower gas mileage.

automatics have improved over the years, and in some cars, the automatic is only about 1 or 2 mpg lower, but the automatic is still worse on fuel economy.

if it makes you feel any better, i have a manual in my car, and i am only getting around 27-28. dont worry about the fact that it is the xrs and i am heavy with my right foot though.

yeah but ive compared it to my camry with a larger engine and about 500 more lbs and its the same.....that doesnt make sense...they BOTH have automatics...is the camry just MORE fuel efficient overall?? I highly doubt that is the way toyota designed these cars...a lighter car with a smaller engine gets the same mileage???

[Smar969905]

Originally Posted by kevintomb

yeah but ive compared it to my camry with a larger engine and about 500 more lbs and its the same.....that doesnt make sense...they BOTH have automatics...is the camry just MORE fuel efficient overall?? I highly doubt that is the way toyota designed these cars...a lighter car with a smaller engine gets the same mileage???

the larger motor gives it enough more power that it doesnt have to work as hard, even with the extra 500 lbs. compare the power to weight of the matrix to the camry (use the torque, not the horsepower because horsepower doesnt really mean anything for power).

my uncle had a 2000 corvette with a 6 speed manual. the car was all tuned up for racing and he was able to get up to 28 mpg out of it, because while driving it, the motor didnt have to work very much to keep the car rolling.

here is another example:
go pick up 100 lbs
have somebody else around you who is much stronger, but also heavier than you pick up that same 100 lbs.

you had to work harder to get that 100 lbs to move than whoever else, because the other person has more power to spare. it is something like that why bigger motors can keep around the same mileage as smaller motors, at least until you floor the gas and use all the power it has...

[SGS]

maybe a dirty air filter??? and oil change??? I usually think it's placebo... but after I change them I usually think the car goes a little further in the milage....

[Smar969905]

Originally Posted by SGS

maybe a dirty air filter??? and oil change??? I usually think it's placebo... but after I change them I usually think the car goes a little further in the milage....

air filter is very easy to check and change. if you go to get your oil changed, dont worry about the air filter as most places will check it and replace it for you. if your oil is relatively new, the air filter is very simple to get out, and check. it takes about 2 minutes to pull it out, check it, and put it back in if you havent done it before.

find the big black plastic box that is off to the right side of the motor. there are 3 or 4 metal clips that hold it on. find these clips on the sides of the air box and pop them all open. pull the far side of the air box from the motor up as the back end has tabs to help keep it locked in place. those tabs work like hinges until you get it open enough then you can pull the whole top part away. inside you will see the filter. pull it out. if this is during daylight hours, and the sun is shining, then hold the filter up toward the sun and look at it. if you can see light through, then the air filter is just fine. you can try to shake it out a little and tap it against something firm, like the side of a building, to try to get some of the dust and debris out. if you can't see light through it or it is difficult, then your filter is done for and it needs to be replaced, so put the old one back in and drive to you local autoparts store, and buy a new one for about $10. make sure that you put the filter in the correct way when you do put it back in. you dont want to put the side that catches all the crap to the motor side because then you will blow all the crap into the motor. line the top of the air box back up and lock it down with the clips.