[mmason]

Hello all, I need your help. I bought my daughter a used 2000 ZX3 hatchback Ford Focus with a 118K about 3 months ago. I have the Zetec 2.0 DOHC. The car, to our disappointment, only averages about 20 mpg in the city. I have read hours of posts on this site, great site by the way, and have tried the following with no change in 20 mpg.
So here is what I have done.

Transmission Flush, dealer says operating fine
Oil Change, synthetic oil from Ford (a blend they suggested)
New air Filter
New plugs & Wires
New Fuel Filter
New O2 sensor upper
New DPFE sensor
Used EGR regulator
Cleaned MAF sensor
Took EGR Valve hose off and plugged. Car seemed to do better at first on mileage, but then engine light came on and mpg dropped to about 15, so I re-installed the hose to the EGR Valve.
Reset ECU, by disconnecting the battery cable.
Dealer checked and no codes are present
Dealer perrformed fuel system/injector cleaning

My question to you all is how to troubleshoot the problem? I have taken the car to two Ford dealerships and they say there is nothing wrong with the car. The one dealer hooked the computer to the car and it read that it was averaging 27mpg, which is not true. I have averaged multiple tanks of gas and 20 to 21 mpg is the best I can achieve. I checked for vacuum leaks. The hose on the back of the motor below the CAI intake, which this forum has noted as failing, has been replaced. The car appears to be running great but poor mileage. How does a 2.0, 4 cylinder only avg. 20mpg I have noted from several people in this forum that they are achieving much better mileage then I am seeing, and the sticker reports 25 city & 33 Highway. My daughter does about 90% city driving.

Thanks for any and all help in advance. My daughter is crying the blues everytime she is fills up her gas tank, and Dad is out of ideas.

 

[dullishpage]

tell your daughter to drive slower, and to accelerate slower, don't stomp on the gas a lot. not saying she drives fast, but it does make a difference, also frequent stops and accelerations from a stopping position in a urban area is what wrecks mpg.

 

[SkyPilot]

with a lot of the stop and go driving that is city driving, how you drive the car is gonna make a huge differance, but constantly going from idle to a few thousand rpm's is going to burn through much more fuel that staying at a constant rpm.

idk what your problem could be, me personally i average around 31 on the highway, and i have been in santa monica cali for school the last month, and with stop lights at every section, and only getting to about 40mph i have been averaging about 18mpg due to the stop and go driving

 

[mmason]

good comments, but I drove the car for about two weeks myself and never went over 3000 rpm on takes off or at any other point and had the same results 20 mpg. I do not believe the poor gas mileage is a result of driving the car to hard or stomping on the gas.

 

[BeeFzX3]

I don't know if it will help, but you could try fuel injector cleaner. Keeping RPMs under 3k helps a lot. Running A/C will also decrease MPG.
Turn off A/C, keep RPMs under 3k, throw away all the junk out of the car. Also check tire pressure.
Other than that city driving is why you get such low miles.
Try going on hwy.

 

[Master-Baits]

To see if it is your daughters' driving (the biggest factor in fuel economy) switch vehicles with her for a week (if applicable). Drive it verrrrry conservatively, treat the accelerator as if it is an egg. Calculate your mpg's, and compare...you may find your daughter has a heavier foot and accelerated rapidly between stops. Other than that I don't know.... I know I can average as much as 23 -24 mpg in pure city driving with my svt... with the regular zetec not being as hot a motor you should definitely be able to do that AT LEAST. good luck.

 

[PumkinSvt]

put on a new coil pack???

trying to help lol

 

[SkyPilot]

what about highway? city driving really does degrade fuel economy.

also check this out, fuel economy tests are done on a dyno to simulate driving conditions not real world driving

http://www.fueleconomy.gov/feg/how_tested.shtml

 

[BeeFzX3]

oh yeah also having 118k on the motor decreases MPGs

 

[dullishpage]

could also have to do with where your getting your gas, could be bad octane, contaminated possibly, try a different gas station.

 

[bluefront]

I went through almost everything suggested in this thread.....my mileage remained constant at about 25.5MPG 50/50 mixed driving. The only thing that made any difference.....installing a Steeda SRI. The mpg immediately went to 28.5.

Unknown to me if such a mod would do anything for you.....

 

[Master-Baits]

i personally don't think 118k is enough to degrade fuel economy THAT much, i think its more of the driver's style. unless they were a HARD 118k, lol. My friend's dad's f150 had 350k on it when the odometer broke 4 years ago and he drives 60 miles round trip everyday and he got similar mpg's (when he checked before the odometer broke) that he did when the truck had 50k on it.. rediculous truck...and it just keeps going and going

 

[mlbbaseball]

here is a thought, check the air/fuel ratio!!! you might be running way too rich!! if you are, then at least you know the problem!! or part of it anyway!! Do you smell excess fuel?

 

[mmason]

What is the best way to check the air/fuel ratio? I smell no fuel from the car and the tail pipe is clean, not covered in black like fuel is being passed through the exhaust. I also had Ford do a fuel system/ injector cleaning, that cost $150.00.

 

[mlbbaseball]

you can do the tach reset. hold in the button on the tach, then start the car. Hold it till it says test and then release the button, you can check ur cars on board functions w/ that, I am not sure which one is the A/F, but it should be in the 14.X's if its less than that, you have an issue!!

 

[heelflip101]

oops I even read it too.

 

[mlbbaseball]

he said "He" drove it!!

 

[mmason]

you can do the tach reset. hold in the button on the tach, then start the car. Hold it till it says test and then release the button, you can check ur cars on board functions w/ that, I am not sure which one is the A/F, but it should be in the 14.X's if its less than that, you have an issue!!
__________________

any idea which one it may be folks. I did the tach/reset and did not see a air/fuel ratio. I also looked in the forum a while back at the list of the dash board codes and they did not list the air/fuel ratio....thanks for all the input so far.

 

[mlbbaseball]

I can't remember at this time. but I think its like the 8th one. its the only one w/ the number in the 10-20 range!

 

[Lolly]

I know it's not much of an answer, but it might just be a "lemon" in the mpg department. Heck when you start looking around on here you'll see people w/ a fair amount of money dropped into the motor getting 30+ mpg, while others get mid 20's, and still others on pretty stock motors get low 20 mpg. Eric "Svtzx555" gets real low mpg regaurdless of how he drives, & what fuel he runs. He works @ Ford. If there was an explanation for it I'm sure he'd love to know it also. Sorry, I know I wasn't any help. I'd say save the money on tests & start modding it for her. [^]