Why am I not getting my suggested MPG???

[Blue636]

OK, I know the sticker is always generous (at least that's what I believe) but when I bought my car it said 28 street and 33 highway. Besides the day I drove to Las Vegas and back... I have not seen a single fill-up in where I even broke 28mpg average in my car. It's usually between 24-27 (27 if I'm really lucky).

Here's the deal... I keep my tires inflated close to the recommended pressure. 44 is max and I keep mine at 42. I don't accelerate like a bat out of **** and I usually take it rather easy - no offense to you drivers but I think cars are BORING compared to my motorcycles. I also rarely carry many passengers... it's usually my wife (107lbs) and my baby daughter (18lbs +/-). I use the recommended viscosity for my car - Mobil 1 5w-30 and I also use the minimum recommended octane which is 87... I don't have a problem with engine knocking at all. I've basically tried to factor in weather conditions, idle time, warm-up time (about a minute give or take a few seconds)... and I'm still not getting the gas mileage I want!

What upsets me is that gas mileage was a major factor in considering a new car - without going so far as buying a goofy-looking hybrid. Is this normal? I'm rather disappointed... I was getting better gas mileage on my beat up '88 Acura Legend with a V6 engine (198,000 miles, very surprising considering my abuse and 15,000 mile OCI's before I knew better) and here I've got a 2003 Toyota Matrix (14,600 miles) which is supposedly better on gas but it makes the old Acura look good.

Sorry for the whining rant, but I feel like I was ripped off because like I've said, the major reason we bought a new car was to get better gas mileage in anticipation for gas price hikes. I'll stick to my bikes... 36mpg on one and 55mpg+ on the other! My wife can drive the car and pay for gas on it.

 

[Shannow]

In short....I dunno.

I keep what the guys at work refer to as an nalay retentive logbook. There is a 10% mileage difference between me and the better half. Ever time.

Funny thing is, even when I'm passenger, I can't work out why her economy is significantly worse than mine.

 

[Bobert]

Here are a few suggestions:

--New spark plugs (with correct gap)
--New air filter
--Have you had an alignment lately?
--Check Mass Airflow Sensor and maybe clean with alcohol.
--Oxygen Sensor could be faulty.
--Are your brakes dragging on one of your rotors?
--If you have a manual transmission, use synthetic gear lube.
--California most likely gets funky formulated gas, which could be affecting mileage (vs. EPA sticker).
--Aggressive high perfomance tires can affect mileage with increased rolling resistance.
--Cooler temps will increase gas mileage, since air resistance is higher, and affect air/fuel ratio.
--Concrete highways will get better mileage than asphalt. FWIW
--Your tire pressures are Ok.
--All these things add up.