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Discussion Starter · #1 ·
My gas mileage often floats between 30.0 and 30.5, depending on the amount of traffic I hit in a given week. I would like a better way to view my gas mileage so I can see when I'm close to increasing/decreasing by .01. Is there any way to quantify the amount of gas in my tank? I can assume the total number of gallons based on the size of the tank, and where my fuel gage is sitting; but this is only an approximation. Would I be able to get more of this info using an OBD2 reader (if so, does anyone have any recommendations for one that works well with Android)? How do you track your gas mileage?
 

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It would be difficult to reliably measure that precision...

Tank to tank, the internal MPG computer isn't really accurate enough to give you a good idea of your gas consumption. You generally need a few tanks before the average reflects your true average MPG.

Using a scan gauge would be better but not by much. It only measures (along with the trip computer) what the gauge is sending to the computer and is usually no better than hitting 'reset' on the trip computer for your average economy -- it's gathering exactly the same data as the car. You can have it display that data unedited but its worth is very little because most cars today are able to compensate for any changes during driving so that a more uniform, accurate reading is produced, but it's still not perfect. If you just display the raw data, you're missing out on the compensation for tank shape and sloshing gas.

You're looking for a ten-fold increase in the precision of the car's reading and under most circumstances 30.XX won't be any more reliable than 30.X. The only way you could trust 30.XX is if you drove the same route in the same temperatures with the same traffic and the same accessories going the same speed. The more variability you introduce into your driving, the less 30.XX will reflect your true average.

Heck, 30.X isn't probably too accurate if you're looking at just one tank.
 

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http://www.scangauge.com/

I have a scangaugeII. Had the old original scangauge and some tool that needs there hands shot off broke a window in my car and took it.

Unit will give you all sorts of info. MPG real time, tank, segment's, multiple trip meters. Intake air temp, O2 open or close loop, load, throttle position., speed, ave. speed. MPG per hour all sorts of stuff.

The owner of the company is very nice. As is his son and everybody I've met there face to face in Phx.

How on earth are you only getting 30 mpg in a Focus. It barely goes faster if you hammer a 2.0. I LMAO watching people burn up gas passing me on my daily grind just see them hung up at the next light light I am. :)

Good Luck
 

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Discussion Starter · #4 ·
Tank to tank, the internal MPG computer isn't really accurate enough to give you a good idea of your gas consumption. You generally need a few tanks before the average reflects your true average MPG.
I've had quite a few tanks already; I'm almost at 5000 miles.

I see your point about everything else though, it would be hard to be that accurate/reliable. I just was hoping there would be an easy way to see when I'm about to drop .1 [:D]

Is this different from an ODB2 reader and an Android phone? It seems similar to what a lot of the ODB2 apps can do.

How on earth are you only getting 30 mpg in a Focus.
I didn't think 30 was that bad (the sticker said 28-32mpg); but I haven't really looked closely at what others are able to get. Maybe its because I drive an automatic instead of stick?
 

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The SG's are ODB2 tools. But there made as a driving aid. They will also pull codes and clear codes. You can also use X-Gauge commands to customize things and extra data more to your liking.

Some sites also do group buys. I got both of mine through group buys at cleanmpg.com.

I was going to move mine to the new Focus this morning. But I put it off till Friday morning when I fill it up. I hate having to pull it from my MZ3. It's been in that car for many years and I have a very fine setup tune on the SG concerning the MZ3. You can setup offsets and all sorts of things. The newest units may let you save setup parameters as you move it from car to car. Mine doesn't.

OOO damn... That reminds me I need to pull the codes my MZ3 threw just before it started making the noise that made my park it and buy a new car.

Thanks!!!!
 

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"How do you ony get 30 mpg"... Well traffic. A lot of stoplights, a lot of stop and go and you are easily down to 30 or below.
Not everyone has a freeway commute at speed....

If you commute is through heavy traffic on regular streets and lots of stoplights.. you mpg is going to be low.
 

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^^^ yup, as soon as I saw Philly as a location not getting fantastic MPG wasn't a surprise.

Fixed the SP. in the title for ya.

Resetting a trip function to see current changes is the easiest way to see when you're loosing mpg., any of the scan tools that give an 'instant" reading will give you that current feedback all the time.

Precise fuel levels aren't obtainable, too many variations there. Each fill up isn't even precise, "full" will be different each time.

Pencil & paper is the Old School method for tracking that always works, there are 'apps" for tracking over time that many have fun using.
 

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Discussion Starter · #8 ·
Yes, Philly traffic (especially i76) is probably the main cause of my low gas mileage... I plan to find an alternate route at some point.

I always forget I have two trip functions. I'll try resetting one before my ride to work today to see if there is a difference.
 

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It's a good day when you don't come to a halt along that route...
 

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Discussion Starter · #10 ·
It's a good day when you don't come to a halt along that route...
Yeah, I'm the early guy at work this week, so it's been great. It only takes ~20 min from NJ to Bala Cynwyd taking only 76 (if I control my speed ). My gas mileage has been steadily increasing; but once I'm back on my normal shift, it will likely begin to decrease.
 

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There are roads that I can get over 40mpg when traffic is light and the lights are favorable, but if the traffic is heavy and I have to stop at most of the lights my mileage can drop down to about 25mpg or even less. These are the same roads driven in the same car with the same gas.


Brian
 

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http://www.scangauge.com/
How on earth are you only getting 30 mpg in a Focus. It barely goes faster if you hammer a 2.0. I LMAO watching people burn up gas passing me on my daily grind just see them hung up at the next light light I am. :)

Good Luck
I'm pretty sure he is referring to mixed, overall MPG's... I coast as much as I can and still average only 29 MPG, 50/50 driving, leaving the computer alone for a few tanks, tires firm at 40 psi. On my long road trips I get about 35 MPG driving about 75 MPH for most of it. I think that's just about right, I'd like to get it up a bit more but with gas dropping in price big time, I'm not too worried about it at the moment. With 31.5k on the odometer maybe I should run some good fuel system cleaner through? I'll ask i nthe performance area...

I didn't think 30 was that bad (the sticker said 28-32mpg); but I haven't really looked closely at what others are able to get. Maybe its because I drive an automatic instead of stick?
I surprised you would think that as it's an automated dual clutch internal manual that, as far as MPG's are concerned, is more efficient than a manual. There is no torque converter to steal power and MPG's... you get better MPG's but lose manual control of downshifts/being in the exactly gear you want.

So if you're getting 30-30.5 mixed, cool, that's pretty much exactly what you should be getting... Yes, it would be nice if our cars had both a real-time AND average MPG's like some other cars, but they don't... is that what you mean by your original question? Is there a way to tell real-time MPG's? I remember this being asked before and I believe you have to buy an aftermarket display computer that will tell you. You would have to thread search deeper and find the info.
 

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I filled up my new Focus this afternoon when I left work. And installed my SGII. Did a straight default install of the SGII. Meaning I set it up for 12 gal gas tank size, 2 Liter gas burner, bus as basic CAN with high speed refresh and car as hybrid. It was exactly 1 mpg off on the high side compared to the cars trip computer. I had to do some running around in Tulsa city traffic with 1 mile back ups the norm, beep and creep crap the norm and fender benders every 3 to 5 miles cause folks are complete idiots. 50 miles of crap city. 25 miles of clean hwy at 60 mph. Let them pass me all they want. I catch them at the first or second light when I hit the next town. 40mpg.

The dealer tank fill did not count for much in my basic new car mpg figures. My two tanks, both 11 gal fills came in near perfect with the cars calculations. Within .02 mpg of cars display doing the first grade math. The SGII needs some slight offset setting made to it. The injectors on the Focus seem to dwell at a diff. angle then Honda's, Mazda's and Yota's. And that's fine. I do wish the SGII would let me look closer at the injector timings and trims verse's the cam grind and and auto adjustments built in to the design. And the harmonic, voltage pulse width. It also appears the Focus doesn't use a true Atkins Cycle like some Hondas and other more well engineered systems. MAP is a unreadable mess of data. That tells me pumping loss is not a concern of Ford in USA spec cars. Or at least in mine. If they used a true Atkins Cycle control pattern and design engineering the transmission would be much easier to control. Especially from a stop.

Another point of interest I saw today on the SGII was air intake temp. It was rock stable at 66F. As the cars reported air temp was 60 to 50f, strange swings in outside air temp, but I was driving over hills and through valleys. Which was spot on with my Fluke air temp taken at the back of the car in the shade as I was driving alot of east into the setting sun and dark as I headed south. Yeah I can go nerd over these type of things. I haven't looked at the intake system yet on the Focus. So I don't honestly know if it is thermostatically controlled off the the throttle body/servo system with water from the engine cooling system. In the winter these could be great intake air temp diffs. Or it could be a HP and mpg killer in the summer months.

While this 2 liter engine is basically the same as the last gen Mazda3 2 liter. Mazda took a different look at controlling the engine than Ford. As did Mazda with the 2.3L in my 07 MZ3. Thank God Mazda introduced a better less parasitic balancing system as well as better motor mounts than Ford ever used in there retail products. And the sick thing is. Mazda's system slips right in in the Fords. If it's American you can bet you last dollar on half ass engineering and production. We can't do that because we refuse to spend $50 more. Look no farther than Sync. The cheapest POS on the market powered by Microsoft. What does that tell you. Hello Corn Hold!

I'm Loving My Focus. :)
 

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Little OT, but you might look closer at WHICH engines have an added "balancing system".

2.3's & the ST 2.0 do, the 2.0 in your car doesn't.
 
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