General Technical & Electrical General technical and electrical discussion for the Ford Ranger that does not fit in any other sub-forum.

MPG vs SPEED

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Old 12-26-2007
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MPG vs SPEED

Was playing with my new scanguage on the way to work this morning. It was very cold at 17F and these numbers are in no way conclusive... just thought you guys would like to see a speed vs instant MPG relationship.
(all driving was steady speed, flat ground, no wind, and fairly foggy)

 
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Old 12-26-2007
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id believe it, rangers are so poorly areodynamic
 
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Old 12-26-2007
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The MPG curve on my www.cartestsoftware.com program shows I should be getting even less milage. I'm trying to figure out why so I can make the program better match real life. (1/4 mile, mileage, and towing info)

btw, Before I even had this scangauge in place it's been my overall observation that when I go 65 vs 70 there has been a significat difference in mileage. Now that I can read it live.. it confirms what I've been thinking.
The supprising thing to me is that below 55-60 it doesn't really improve much. The dramatic step seems to be 65mph and above.

Rich
 
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Old 12-26-2007
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I see you have an X-cal2. Is the scangauge part of the X-cal or a seperate unit?

If you have several programs to use in the X-cal which one gives better fuel mileage and how much over the original Ford program?

I have a 2003 Ranger Edge 3.0L 4.10 L/S automatic and get 25mpg @ 65mph, 20mpg @ 70mph and 18mpg @ 75mph. Tested this several times and it's always the same +/-.5mpg. I am considering buying a tuner from Bama tuners, is that where you got yours?

I get about 19mpg when I mix town, road and interstate driving. I'm a conservitive driver trying to get good mileage but I do pass slow traffic on two lanes occasionally and that would reduce mileage.

On the interstate I like to drive at 75mph so I would like to change the program to get at least 22mpg @ 75mph.
 
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Old 12-26-2007
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The X-cal and scanguage are two seperate things.

As far as the x-cal.. get it and your tunes from Fred at rouge performance or James Hanson at hanson performance. Don't buy it from Doug at bamachips unless you like the pain of beating your head against a wall.

I've ran 4 different tunes and they all get about the same mileage. And yes they are all better than the stock tune. The x-cal alone bumped me up by 1.5 - 2.0MPG.

Rich
 
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Old 12-26-2007
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So, I can expect 2mpg tops and the tuner hits me for $400. It's going to take a long time to recoup the investment.

How much does the performance programs improve the performance?

It seems the advantages may be the ability to change from economy to performance and modify the high speed limiter, acceleration limiter and shift points.

Doesn't the X-cal have a scan freature to monitor the sensors, speed, rpm fuel mileage, etc., is that true? If not what does it monitor
 
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Old 12-26-2007
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So can you explain to me why someone would get better mpg on a trip? or is that just because consistency at 75mph lets say.

alot of variables in there but still pretty cool. would be neat to see this on my truck, i bet it starts to fall much earlier.
 
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^^^I would agree with that!
 
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Old 12-26-2007
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I played around this weekend. You can change your driving habits to fit mpg.

As an example. Accelerating drops mpg's down to 4-6 mpg. Once you are steady it jumps to 19-20. When you deaccelerate it might jump to 50mpg during that time. Drop in neutral and it may jump to 150 during that time.

It reminded me of roadcourse racing. How you make the corners impacts your times. Brake early and accelerate out of the corner faster, or brake late and come out of the corner slower. Thats what the ScanGauge reminded me of but in a mpg state of mind.

Slow down early at a stoplight rather than keeping speed then braking is a good example. It's all common sense but this kind of brings attention to it.
 
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Old 12-26-2007
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Originally Posted by Ranger Carl
So, I can expect 2mpg tops and the tuner hits me for $400. It's going to take a long time to recoup the investment.
Yes it will.

Originally Posted by Ranger Carl
How much does the performance programs improve the performance?
The power increase is VERY noticable. I for one like the timing maxed which give a very nice preception of power at low throttle input. (I run sunoco 94 or 93)

Originally Posted by Ranger Carl
It seems the advantages may be the ability to change from economy to performance and modify the high speed limiter, acceleration limiter and shift points.

Doesn't the X-cal have a scan freature to monitor the sensors, speed, rpm fuel mileage, etc., is that true? If not what does it monitor
The x-cal allows you to look at many many functions. But you need a laptop sitting beside you all the time. That takes effort and time to fire up and use.
The scanguage is on as soon as you turn the key. It's there all the time and displays 4 signals. With the push of a button you can quickly go to a different parameter. The x-cal and a lap top would require you stopping the datalog, using the pointer to go select another parameter, and then restarting the data log. That's a HUGE pain when your driving down the road. And really.. the x-cal / datalogging is best left for WOT blasts or trouble shooting in the garage.

Rich
 
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nice look Rich...

I see a tremendous increase in milage with the X2 93 Torque tune (with me modifying a few perimeters) over the stock computer configeration......I modified it so the spark is advanced 6 degrees @ 0-2000 rpm's, advanced 4 degrees throughout the remaining rpm range, and the air/fuel ratio is up 6 percent.......with the tune set like this I get roughly 18 mpg on the highway @ 75 mph and 15 mpg in the city......that is 3 mpg better on the highway over when my truck was 100% stock
 
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Old 12-26-2007
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Originally Posted by zabeard
So can you explain to me why someone would get better mpg on a trip? or is that just because consistency at 75mph lets say.

alot of variables in there but still pretty cool. would be neat to see this on my truck, i bet it starts to fall much earlier.

Fuel consumption is a mathmatical factor. Mostly influenced by displacement. (engine size & rpms used)

Once you've used fuel to get to hwy speed it take less fuel to keep that mass moving than it does to slow and re-accelerate.

Having the milage read live will help you to see when it is that your consuming more fuel.

For instance. Cruise control when going up/down hills can only react to speed. The throttle will go heavier and lighter than if you were to just accept a 1-2 mph dip or rise. This morning I did this actually. With the CC on the mileage will drop to 14-15 when going up a hill and then go up to 25ish on the down slope. Keeping the speedo right on 72 the whole time. Well.. when I controll the throttle **I** can antisipate the hill. I can slightly speed up before getting there and then not push the throttle as hard when climbing. Then on the down side I back off just enough to get back up to speed by the time I get to the bottom. When doing that my milage usually only changes by about 2mpg at most. (my caddy has this feature too)

The steeper the hill the better milage you'll get by controlling it yourself. Out on a mostly flat hwy the CC would probably do a better job at it than would you. (humans get distracted and forget what were doing. A CC is 100% dedicated to maintaining the speed. That's it's sole purpose in life)

Rich
 

Last edited by wydopnthrtl; 12-26-2007 at 11:06 AM.
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Old 12-26-2007
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It looks like I am going to get both the X2 and the scan gauge. I am a tinker at heart and I like the idea of setting the program as I like it.

There is a cheaper way to control your driving to get better fuel mileage. If you put a vacuum gauge on your dash and watch it as you drive you'll soon find the vacuum responds just like the scangauge would with movement of the accelerator to display fuel mileage. The scangauge as I understand, watches many other things.

edit: Rich is right, the cruise will cost fuel mileage in hilly country. My Ranger kicks down to much for my liking so as I aproach a hill I kick it out and drive it myself to keep it from droping lockup and overdrive. On flats I use the CC. Throttle management is paramount to getting good fuel mileage thats why I wonder if the X2 will really help me since I seem to get better fuel mileage than most here do.
 

Last edited by Ranger Carl; 12-26-2007 at 11:14 AM.
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A vacuum guage is limited and is actually a *indirect* guess at fuel consumption. The scanguage is actually taking into account the fuel entering the engine. Would you rather look at the wrapper or the thing inside the wrapper?

Rich
 
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Old 12-26-2007
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In reality the vacuum is an indicator of fuel mileage on an indirect basis. The scangauge is just a high tech instrument that electronically computes the alledged mileage that is being obtained. There is no guarantee the indications are exact, it's just a tool as is the vacuum gauge.

The idea of the vacuum gauge is to keep the vacuum at a certain spot during driving.

The idea of the scangauge it to keep the fuel mileage shown at a certain spot during driving.

The only difference is one shows vacuum in inches/mercury and the other shows miles per gallon digitally displayed.

It's the act of keeping the numbers the same as much as posible all the time is what will get a better overall fuel mileage, not having the most expensive testing equipment.

I haven't had a vacuum gauge mounted in a car since the early '60's and they do help but if I can get more info electronically now by pluging in an instrument and monitor things it would be an improvement over the vacuum gauge but at a much higher expense. The decision is how much to spend versus info gained. I do like the scangauge features but the fact remains it is only a tool and if it's not used to alter your driving habits it is a waste of money and time.
 

Last edited by Ranger Carl; 12-26-2007 at 11:35 AM.
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Old 12-26-2007
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Carl,

As a OEM automotive engineer I fully understand the differences. And like I made an analogy.. would you rather see a picture of what the product looks like.. or the product it'self?

It's true that a PCM interface will indeed cost more. Won't argure that at all. But your not seeing the whole picture with a simple mechanical guage.

For instance, some cars have fuel cut when you lift the throttle. A vacuum guage would show you the same at full off and slightly on. Looking at the actuall fuel being put into the engine would show a much bigger difference.

But... we are splitting hairs here. No biggie either way.

regards, Rich
 
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Old 12-26-2007
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I see what you mean Rich, the electronics in the PCM are light years away from vacuum gauges.

I added an addendum to my above post before I read your last post.

My issue is I would use the readings on the scanguage to help my fuel mileage but I wonder how many buy them and see the display and just keep on driving the same way they did before.

When I joined the forum I started looking for mileage threads because my 2003 3.0L ranger gets less gas mileage than my 1991 4.0L Aerostar @75mph.

Ranger=18mpg, Aerostar=22mpg. Same tranny and both 4.10L/S rear ends. So, 12 years later and a more powerful 4.0L '91 get better fuel mileage than my'03 3.0L. That must be Ford's better idea I guess.

On the other hand, if an after market company can reprogram to get better mileage why can't Ford.
 
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Originally Posted by Ranger Carl
On the other hand, if an after market company can reprogram to get better mileage why can't Ford?
Excellent question!
 
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Old 12-26-2007
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Originally Posted by Ranger Carl
On the other hand, if an after market company can reprogram to get better mileage why can't Ford.
We all know that a good aftermarket chip or flash tune can increase both fuel economy and power. The most important changes are increasing the ignition timing lead and leaning out the open loop fuel tables. Believe it or not, the factory engineers know about this, too, but they operate in a world with a different set of rules.


Here are a couple of quick examples although it is actually considerably more complex than this:
  • Catalytic converter temperatures must be high enough for good conversion efficiency but low enough to prevent premature aging of the cat. Car and light truck manufacturers are required by law to warranty cats for 8 yrs/80,000 miles and warranty replacement of a set of cats costs several hundred dollars.

    Higher internal temps mean that the effective service life of the cats is shortened. To keep the conversion efficiency high enough to perform to 80,000 miles and beyond, the factory calibration engineer must keep the maximum cat temps below some design target temperature. Depending on the proportion of precious metals used, that target might be 1650F or something similar.

    The temperatures in the upstream cats are controlled primarily by the air/fuel ratio and the distance from the combustion chamber. For WOT power, the best A/F ratio is around 12.0~12.5:1 but cat temperature protection may require that the calibration run the A/F as rich as 11:1 in some speed/load cells.

    With respect to cat life, all the aftermarket tuner really has to worry about is keeping the temps comfortably below the melting point of the substrate which is around 2200F or so. For most powertrains, this is easily achieved even at the A/F ratio that delivers peak power. This means that the aftermarket calibration can be tweaked for WOT power as a primary goal. As a result, the aftermarket WOT calibration may be leaner than the factory cal, yielding more power and better WOT fuel economy. It's a win-win situation as long as long-term catalytic converter life is not a primary consideration.

  • At many speed/load points, more ignition advance means more power. At higher RPM and throttle openings, the maximum amount of advance is detonation limited.

    For most vehicle lines, Ranger included, the specified fuel is 87 octane regular unleaded. Ford is not going to sell a Ranger (basically an economy vehicle) that requires premium. That would drive a lot of sales away.

    The factory engineer must come up with a spark table that will work with the factory recommended fuel everywhere in the intended market. The table also must work with any production tolerance stackup that may occur and it should continue to operate without detonation as carbon builds up over the life of the engine. The production spark table is finalized in low humidity desert testing because dry air is the worst case for detonation. What works in more humid parts of the country could detonate badly in the desert Southwest.

    Using premium fuel allows more spark advance in high load/high RPM cells and the engine can make more power. A good aftermarket calibration that is set up for premium fuel will make considerably more power than one set up for regular and may offer a fuel economy benefit at part throttle as well. No surprise there.

    However, even when tuned for 87 octane fuel, the aftermarket calibration has an advantage. It does not need as much "cushion" as the factory calibration because it can be tailored for an individual vehicle in a particular part of the country. Factory calibration engineers must hold back about 1~3 degrees as a hedge against production tolerance stackup, carbon buildup and regional climatic differences.
 
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Old 12-26-2007
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rwenzing, that explains it in a way I had not considered or heard before. I knew the temp of the C conv. had to be maintained within a range. Now that you have put it together that way I see it in a broader picture. If I do buy a reprogrammer I know something about what to consider.

I will do a search on the C conv. as I have some questions.

I sure would like to get 20-22mpg @ 75 with my new/used Ranger on the 87 octane. There is most always a 10 cent difference between fuel grades. I would have to do the math to determine if there would be a gain worth while gain between 87 to 91 or 93. Since I haven't used 91 or 93 and the engine is most likely set for compromise it may not mean anything. Also, my engine is a Flex Fuel and my PCM may be set different from the non Flex Fuel.

When I got this trk last July I was disapointed in the mileage and began keeping a lot of records. I am 66 and this may be the last trk I buy because I always put over 200k on my vehicles and since I'm retired the miles per year will be lower now. I don't drive near as hard as I used to so I don't often scare myself or others now. I still like performance AND economy so haveing two or three programs to use would be nice.

Thanks for the info, I understand Ford's side a little better.
 
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Old 12-26-2007
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Originally Posted by Ranger Carl
I sure would like to get 20-22mpg @ 75 with my new/used Ranger on the 87 octane. There is most always a 10 cent difference between fuel grades. I would have to do the math to determine if there would be a gain worth while gain between 87 to 91 or 93. Since I haven't used 91 or 93 and the engine is most likely set for compromise it may not mean anything. Also, my engine is a Flex Fuel and my PCM may be set different from the non Flex Fuel.
I think that if you look at the consensus on this and other Ranger boards, you will probably find that the per-mile cost of operating a 93 octane tune vs the factory 87 calibration is close to even. About 7% more per gallon for the premium fuel at current rates vs. about 5~10% increase in MPG, depending on who's telling the story. The more significant gains are the extra power and adjustability but that is balanced against the $400 tag for the tuner.
 
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Old 12-26-2007
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From Bob:

The temperatures in the upstream cats are controlled primarily by the air/fuel ratio and the distance from the combustion chamber. For WOT power, the best A/F ratio is around 12.0~12.5:1 but cat temperature protection may require that the calibration run the A/F as rich as 11:1 in some speed/load cells.
Bob, the CAT will actually run hotter with the richer mixture.
 
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Originally Posted by Takeda
Bob, the CAT will actually run hotter with the richer mixture.
Only in the presence of excess oxygen.
 
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Originally Posted by rwenzing
Only in the presence of excess oxygen.
The temp will go up with a richer mixture, just keeping the O2 concentration constant.
 
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The exhaust is in a very low oxygen state at during WOT fuel enrichment. Going beyond the normal WOT enrichment is a common technique used when necessary to reduce cat temperatures.
 

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