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I've been in two different Focuses and I've gotta say the mileage went down after I switched to the 05 with the Duratec engine. Had an 03 with a Zetec engine before and my driving habits have not changed, but mileage went down and I think that is good enough cause to say it's the car.


The car's EPA rated 26 city/35 highway at the time, 22/32 under new system.
The worst I've gotten was 19.5 ish due to a full-blast A/C and 2 hour stop and go
The best I've got was 55-75mph, minimal speed change, minimal brake smooth highway driving on cruise control and that was 34mpg

I've been keeping track of the mileage as often as I can since new and I'm not too happy with the 27 mpg average.

From 68 fillups, this is what I have:
27.3mpg mean (corrected = 27.6)
2.946mpg standard deviation

This gives me a 95% confidence range of
26.6 to 28.0 mpg (corrected = 26.9 to 28.3)

Reason for correction: +1% correction due to odometer reading short compared to GPS.

Most of my driving is in Portland OR suburbs and I use the freeway a lot, so I'd say 70% highway and 30% city. I don't accelerate hard and you don't use A/C much in Portland OR and I shift very early and despite my driving being mostly highway, my mileage is closer to city than highway.

http://img503.imageshack.us/img503/4600/milespergallonwz0.jpg
Black line = attempt at linear regression, but the R value is something like 0.04. The declining trend may have something to do with increasing use of 10% ethanol blend from 2005 to now, which by the way is required by law in Oregon since April or so in Portland metro area and is basically the law in entire Oregon now.(a few counties have until September)

Each data point is calculated using the traditional method of dividing the odometer reading change over gallons filled. I don't use the scan gauge gimmick, whose accuracy is dependent on fuel consumption reported to OBDII port.

That does look a bit low to me, especially with the Duratec 20 motor - it's an excellent economy motor (I assume it's the 2-liter, not the 2.3?), and with the ZX/3 being the lightest body I'm doubly surprised it's so low. I'd have expected over 30mpg average with a peak closer to 40. My '04 SVT averaged about what yours did and bested it on two tanks on the highway, and that with the old, early-90's designed Zetec motor tweaked by Cosworth for power, not economy, and carrying around about 200lbs more than a base ZX/3. I'd suspect you're onto something with the E10, but for the fact that I think they have E10 here too. How inflated do you keep the tires? Are you using the recommended 5w-20 oil? Have you kept the air filter fresh?

I had a 2003 with Zetec with the MTX. The 2005 I have is basically the samething, except it's got the Duratec and A/C. A/C is the reason for trading.

The Zetec's mileage was noticeably better even when the AC wasn't used and since Oregon has always used ethanol during winter, I think there is more to it than E10.

The Zetec was a 2.0L the Duratec I have is also a 2.0L, the standard 136hp version, not the Duratec 20E.

I do run 5W-20 and the tires Fuzion(a bridgestone brand) HRi 205/50R16 on stock wheels at recommended 34 psi and I check it every other month or so.

The car has a Visteon lifetime air filter and the indicator will say when it's clogged. It's not user serviceable. The indicator is not in "warning" zone though.

Lots of little things can rob you of 10-20% of your gas mileage.
Does it take a long time for your engine to heat up? You might have a stuck thermostat.
Are your tires wearing funny? You might have a bad alignment.
Are any of your brakes hot after you drive? You might have a dragging brake.

You also might want to experiment with your driving a little. Do you have a scan gauge to help you tweak things?

I'm averaging 36+ in the same vehicle. Only difference is no AC on mine.
Do NOT believe the hype about the 100K maintenance - your O2 sensor, plugs and filters will need to be replaced LONG before that.
Currently running NGK TR55 plugs gapped at .060", K&N Intake and MBRP exhaust on the factory O2 sensor - 78K on the clock.

Do you have access to anyone with an XCal2, X3, LiveWire or SF tuner? Data logging would provide some great information.

O2's will not trip a code unless they are failing, but degrade long before that.

To add some salt to the wound, I'm getting 31.6 with E85!

If you are ever North of Seattle - PM me, I'll hook a hypermilin' brother up...

Lots of little things can rob you of 10-20% of your gas mileage.
Does it take a long time for your engine to heat up? You might have a stuck thermostat.
Are your tires wearing funny? You might have a bad alignment.
Are any of your brakes hot after you drive? You might have a dragging brake.

You also might want to experiment with your driving a little. Do you have a scan gauge to help you tweak things?

No, warms up fine
Tires are wearing evenly.

I've not had a car with brakes not hot after being driven. It's no worse than anything else I've driven. I don't smell anything funny or see smoke.


some people on Focal Jet forums are commonly getting mileage similar to mine and some are getting way better. I have no reason to believe my driving habit changed between having the 2003 ZX3 and the 2005 ZX5. They're both manual transmission. It's not my driving, it's the car.

.....

I've not had a car with brakes not hot after being driven. It's no worse than anything else I've driven. ....

Mine are usually cool in anything I drive. That might be a sign that DWB and timing stop lights better would help you. Still it sounds like something's up with the car, I just listed off the three easiest things I would check.

Hmmmm.... I recently had a 4 door 2005 focus with the same engine, 5 speed MT & air. That was before learning about hypermiling and I consistently got 26-28 city and 34-36 highway. I could bank on it. It was a pretty good little car but it had a real sloppy transmission.

I did net ~3-4mpg disconnecting the rear o2 sensor on mine, but again it's a Zetec not a Duratec motor. I also run AZFS22C copper core plugs at the stock gap, SVT lore has it that the SVT motors like these plugs.

One thing I did do differently is that I keep my 215/45-17's at the sidewall 44psi. That should make a difference if you try it. I've had two or three tanks over 35, one over 36, and most of the other highway tanks are a consistent 33-34. In town is still on the order of 26-28 though.

Technique check: does it work well to shift at ~1500 and open the throttle to ~75+ TPS to eliminate pumping losses?

I did net ~3-4mpg disconnecting the rear o2 sensor on mine, but again it's a Zetec not a Duratec motor. I also run AZFS22C copper core plugs at the stock gap, SVT lore has it that the SVT motors like these plugs.

One thing I did do differently is that I keep my 215/45-17's at the sidewall 44psi. That should make a difference if you try it. I've had two or three tanks over 35, one over 36, and most of the other highway tanks are a consistent 33-34. In town is still on the order of 26-28 though.

Technique check: does it work well to shift at ~1500 and open the throttle to ~75+ TPS to eliminate pumping losses?

The only way I can get 34 is if go 60mph and only go 70mph when the limit is 70 and staying on cruise control most of the time. If I fillup before getting on the freeway, then I get on the freeway and go 2 hours at the limit using CC, I can barely get 34mpg.

I just drove about 46.3 miles in the Focus and averaged 44.6 mpg just by keeping the speed at 52 mph.

No, warms up fine
Tires are wearing evenly.

I've not had a car with brakes not hot after being driven. It's no worse than anything else I've driven. I don't smell anything funny or see smoke.


some people on Focal Jet forums are commonly getting mileage similar to mine and some are getting way better. I have no reason to believe my driving habit changed between having the 2003 ZX3 and the 2005 ZX5. They're both manual transmission. It's not my driving, it's the car.

on Focus Fanatics, there was a link to a cure somewhere. sign up and talk to Darknight(or something close to that), he had that problem. i did too, an avg of 22-24mpg(before hypermiling). Foci do seem to be weird. ive heard as bad as 17mpg or something. i ran seafoam in my oil n gas, changed the fuel filter n oil(after 250 miles w/seafoam). i was also using e10, but now i use Shell regular, and that helped. oh, i also did plug wires(went bad) and plugs, gapped at .054. now im gettin ~35mpg with my 2000 SPI sedan with ~100lbs audio equipment, and usually 1-4 passengers

I am getting on average 42.4 mpg with my 2005 Focus ZX3. My manual transmission affords me great flexibility when I hypermile. I have been Hypermiling for about 8 months now and havn't been able to break past the threshhold of a mid-40's mpg (i.e. ~45). My best mileage was a 45.6 mpg (all averages based on a 12 gallons usage of the 14 gallon tank). I have never been able to consistantly get over 44 mpg. I am learning that there are some issues that naturally occur with the ZX3. Other drivers on this forum have mentioned a few. Like the driver that has filled up 68 times and swears that his driving hasn't changed and the car is at fault. I have been able to consistently get 42+ mpg out of my Focus.

Here is the weird thing that I am writing to this forum about. It seems that when I make a significant Hypermiling improvement (what I would call a 2-3 mpg improvement) causing my mpg to spike up to 44-45 mpg ... the "NEXT TANK OF GAS" that I put in I continue to apply all the tricks in my hypermiling trick bag plus the new technique ( and I swear on all that is holy) without significant variation, my car jacks with my mileage and I wind up with ~40 mpg. Until I began to monitor more closely and record data I thought that I was not being consistent with my driving. After I began recording this is a constant problem. It makes me very unhappy.

I have never made any mechanical or electrical improvements on my car. I am interested in doing so now. I have heard of bypassing the o2 sensors and adding some special plugs and applying special measurements.

Can anybody explain these options to me. I WANT 50 mpg out of my focus. I think that by all rights I should be able to do it with a manual transmission. Parts or electronics that grossly inhibit my driving are purely annoying. I want to be really good at Hypermiling. I guess that is why I joined this forum.

Thank you,

lars101010

I agree that is low. Our 07 focus(3 dr 5 spd 2.0, no ac or power anything) got 33 mpg like clockwork doing very similar duty(I live in eugene/sprinfield). I could get 40 mpg if I did some hypermiling and took 99 to and from work every day instead of I5, but I didn't do that much cause I was always late and in too big a hurry to drive 55. The low fuel light would come on between 340 and 370 miles and it would always take 10.9 gallons to fill.

I have only been below 30mpg on one fill up after 70k miles, car would die in idle on that tank too. Just normal driving my 05 zx3 manual kept me at 32 give or take 1mpg but pretty darn consistent. Just recently began applying some techniques from here and am at 35.5 over my last 1k miles. Shooting to be able to make a consistent 40.

Interesting. I don't think there is anything "wrong" with the driver ...or the car for that matter. I'm going to take a stab at the ECU being flashed with a more driver orientated factory program. Not all ECU's are flashed alike. Have you tried a full battery reset? disconnect cables fully, ignition on brake pedal down for 30 seconds, leave unhooked for 1/2 hour longer if you want to fully clear the learned program. Reconnect, start and allow to relearn idle for 5 minutes, headlights on 5 minutes (repeat with a/c , blower/defrost etc) drive for 1/2 an hour the way you want it to learn - don't drive it like you stole it! ;)

Regards,
~ 4dse