318is - Bad Gas Milage

[PrinceE30]

So, I've got my new 318is and I took it on it's first long trip from Ohio down to Georgia for the winter. However, the problem is bad gas milage. Really bad. I know some people who are getting almost 400 miles to a tank of gas. I'm getting around 280 miles.

What's the most common problems with these engines that cause bad milage?

-Prince

[Rob]

fuel filter, air filter, o2 sensor maybe. Try new spark plugs along with the filters. I'm sure you're good about tire pressures, but check anyways. Bad tank of gas too maybe?

[DarkWing6]

If the car is new to you some of those items Rob suggested might not be too bad to replace anyways.

[325ise30]

Could be faulty coolant temp sensor, fuel pressure regulator or afm.

[e9nine]

Just as was mentioned, the basic tune up parts.
Next up is how long have you driven it around? Did you get 280 Miles from OH down here to GA? Or are you talking of city/highway driving.
Not all cars will be efficient in the same way. It's all in the healthiness of the motor and your driving habits.

Keep us posted.

[nando]

are you driving mostly city or highway? you got a lead foot? those will kill your mileage.

I tend to do mostly highway driving, although that changed in june when I moved into town. still, until very recently my fuel economy was basically the same (it dropped from 21 to 20) and I still got 26 on longer freeway trips. now I'm at 220 miles and I'm near empty, when I'm used to 300+ miles. I probably need to check up on the motor, but it seems to run fine (runs very strong). I guess I should also try keeping my foot out of it, and getting rid of my slipping auto! :)

[kowalski]

i usualy get 10L/100KM which is 23.52 MPG most of my time is cityish style driving with a heavy foot.

[Tvan]

I've never been able to get more than 300 miles on one tank, the closest I got was like 290, most of which was spent on the highway. I usually average around 240 just driving around town...

[Rob]

I've never been able to get more than 300 miles on one tank, the closest I got was like 290, most of which was spent on the highway. I usually average around 240 just driving around town...

even around town, I get more that 300/tank. I think some tune ups are in order...

hell, even chipped and me ragging the hell out of the motor, my mileage didnt suffer much.

[Dave]

So, I've got my new 318is and I took it on it's first long trip from Ohio down to Georgia for the winter. However, the problem is bad gas milage. Really bad. I know some people who are getting almost 400 miles to a tank of gas. I'm getting around 280 miles.

What's the most common problems with these engines that cause bad milage?

-Prince

Randy, check all of the above that Rob suggested. With the mileage on it I am sure it needs some attention.;)

[Hick]

back when i had a 13 gallon tank, it was no uncommon to get around 320 to 340 miles out of a tank. but now i have a 14.5 gallon tank [325chassis with m42 in place of m20] and i get near 400 miles a tank, as a matetr of fact my last two tanks took me to 405.8miles [most ive ever got of any car] and 396 miles

so 405.8/14.2 gallons = 28.57mpg 95% highway
396/14.5 gallons = 27.31mpg 70% highway

[Rob]

joe's mpg figures are about correct. It varies slightly with weather and traffic on the highway too. Drafting owns.

[hamann318is]

I get about 280 before I feel the need to fill up. The gauge is on 1/4 though. I haven't seen the fuel light in a long time, and I've had 300 on the tank.

I usually average about 27 or 28 MPG around town. However, I did notice a MPG increase with NGK plugs in place of the Platinium +4s.