First MPG reports suk...

[SergntMac]

Yep, it suks...16.8 MPG from my new-2-me #3 Marauder, and the worst mileage I have ever seen from any Marauder I have ever driven. At 2.50 per gallon (today), this ain't working for me. Maybe I need a Focus, and get my stick shift stuff too...

Yeah, it's got 71K on the odo, and it hasn't seen much service at all. But 16.8 MPG is NOT what I expected. I may be a candidate for a de-carbon program, like "Motorvac" maybe.

It's totally "bone stock" folks, so, I'm going to try some fuel system cleaners next. First up will be the Seafoam treatment y'all boasted about here not long ago. Treatments to both the crankcase and the fuel tank. I'll keep y'all posted on what this does, how it works, or, doesn't work. At 6 bucks a pint, we should know more. Next up will be the Lucas fuel treatment, maybe I won't need to go there? If I do, it's NHRA approved, which means squat to me, but looks nice on the shelf.

16.8 MPG is not acceptable for a bone stock Marauder, I get better MPG with my #2 Marauder, the Kenny Brown #1x, with 500 Hp to the ground.

Maybe I need to drive my #2 Marauder this winter?

Naaaah...

[Rider90]

Come on "Up" if you want the Motorvac, you only pay for chemicals. I'm driving slow, very slow, on my stock tune this winter and you're getting better fuel mileage than I am.

[the fat bastid]

16.8 MPG is not acceptable for a bone stock Marauder

it's not? For the first 25,000 miles on my car (when it was stock) I averaged 240 miles till low fuel light, a 15-16 gallon fill up. thats about 16mpg.

when i got the exhuast it when up 1mpg, went back down with the s/c.

in short, i've never seen anything above 280 (exhaust+long trip) on the trip-o-meter when the low fuel light came on. It's almost always 240.

is my car broken? i try to stay out of it to improve the mileage but no dice on anything i try.

[cougarmandan]

I have had my Marauder 3 months now, and it gets average of 19 MGP and as low as 17 and high as 22. Its kind of funny that my Mark 8 gets 24 average and 27-29 highway depending on wind and hills. Both have DOHC 4.6L Modular motors. I expected a little better out of my Marauder for Mileage. But it does weight a whole lot more and it isn't quite as aerodynamic. It also manages to accelerate real well for its size.

[69marquis conv]

Get #3 out and let her stretch her legs- a long road trip might help loosen her up. My stock '04 has averaged 21.8 all along. Max= 24.8, min= 17.4, but when it gets out it goes on minimum 250 mile tripswith very limited stop-n-go traffic.

[jimlam56]

How's the spark plugs?

[rayjay]

$2.50 a gallon? for premium? 87 just hit $2.50 a gallon here today, up 14 cents in a week...

[FordNut]

That's really bad... My wife's stocker gets about 22 on the hwy, almost 400 miles to a tank. Mine gets about 18 on the hwy, around 300 miles to a tank.

Something ain't right.

[HwyCruiser]

Mac, congrats on the new-2-u Marauder. Did you get it to leave bone-stock, hoping to enjoy the fuel economy of having an N/A MM in the stable?

[Vortech347]

low 17's here. Still WAY better than my exploder...i'd be lucky if I saw 11.

I did ALOT of driving over the christmas holiday. 95% freeway doing 85-90mph (yes i'm evil) I went 340miles with a 16 gal fill up. I was Beyond impressed. My explorer freeway was WORSE than city.

[jawz101]

Well a few months ago I saw 11.4 mpg. I had my foot on the floor the whole way.

[Agent M79]

I am usually high 17's, low 18's (that MPG folks, not ETs).

Overdrive off, right pedal down, clear that thing out!

[1stMerc]

Yep, it suks...16.8 MPG from my new-2-me #3 Marauder, and the worst mileage I have ever seen from any Marauder I have ever driven. At 2.50 per gallon (today), this ain't working for me. Maybe I need a Focus, and get my stick shift stuff too...

Yeah, it's got 71K on the odo, and it hasn't seen much service at all. But 16.8 MPG is NOT what I expected. I may be a candidate for a de-carbon program, like "Motorvac" maybe.

It's totally "bone stock" folks, so, I'm going to try some fuel system cleaners next. First up will be the Seafoam treatment y'all boasted about here not long ago. Treatments to both the crankcase and the fuel tank. I'll keep y'all posted on what this does, how it works, or, doesn't work. At 6 bucks a pint, we should know more. Next up will be the Lucas fuel treatment, maybe I won't need to go there? If I do, it's NHRA approved, which means squat to me, but looks nice on the shelf.

16.8 MPG is not acceptable for a bone stock Marauder, I get better MPG with my #2 Marauder, the Kenny Brown #1x, with 500 Hp to the ground.

Maybe I need to drive my #2 Marauder this winter?

Naaaah...

Regane by Gumout is supposed to be pretty could for removing carbon in an engine. Use it in my truck that has 240,xxx miles, periodically and it performs a whole lot better afterwards.

[Skiordie53]

how do you guys get such good mileage my bone stock 04 with 40k miles which we've owned since new averages 15-17mpg and ive seen 21 on a long highway trip. never gotten anythgin great.

[1stMerc]

it's not? For the first 25,000 miles on my car (when it was stock) I averaged 240 miles till low fuel light, a 15-16 gallon fill up. thats about 16mpg.

when i got the exhuast it when up 1mpg, went back down with the s/c.

in short, i've never seen anything above 280 (exhaust+long trip) on the trip-o-meter when the low fuel light came on. It's almost always 240.

is my car broken? i try to stay out of it to improve the mileage but no dice on anything i try.

240 is about the most i get during normal everyday driving (Reinhart tune). Took it from St. Louis to Jackson, Tennessee back in September and hit 283 miles with the needle still a hair above the 1/4 tank mark. That was with the stock tune (but still with Aircharger and Flow Delta 40's) put back on for the occassion and my sister driving most of the way. Got to 294 after i took over, just before the light came on. Now a days very seldom go past half a tank before i fill up.

[Gryphonzus]

I usually get 19mpg and have gotten as much as 25mpg. Highway is usually 23 average. Mine is bone stock 2004 DTR and I do not baby it much. I have 25,000 miles on her.

[looking97233]

Mac,

On winter gas blend I was getting about 13.5mpg city driving and 18-19 hwy. This was on the stock tune. Now with the DR tune, winter gas, I am getting 15-16 city and as much as 22hwy. Best I ever got was a 400mi trip, just set the cruse to 60 (girlfriend dosen't like going fast) got 27.5 that day(summer) the only other mod I have besides the DR tune are Dynomax 2.5"core 18"long mufflers.
Rod.

[03MERCMARAUDER]

On my recent trip home to KS I saw a best of 25 with an average of 22, this at 75 mph and my merc isnt stock.

[DEFYANT]

On my recent trip to and from NY, I managed almost 22 mpg with the Pro-Gard installed. This is up about one gallon over my best mpg with the s/c.

[Marauderjack]

Mac....

Put in a new set of plugs and the Granatelli connectors and I'll bet you get much better fuel mileage!!:beer:

Marauderjack:D

[Bradley G]

Quityerbichen, you got two Marauders.:P

[RoyLPita]

When I got mine, I had the injectors flushed and the vehicle aligned to Carfixer's specs. I also installed a K&N air filter. The lowest I got was 18. I have been getting over 20 mpg as of late.

[CRUZTAKER]

Definately go with the obvious repairs here.
Something is wrong with that milage for sure.

With all the crap I have done, and the hard driving day to day...I always get at minimum 20 mpg.

Perhaps along with the most basic tune ups such as air filter, plugs, and tire pressures, you may want to look at the emissions as well. The EGR and its components, and the A/F mix.

Nice to hear you have a beater-M. :P

[TripleTransAm]

Alignment is definitely worthwhile. Especially on a car with higher mileage, it's had more opportunity to settle or otherwise get pothole-pounded into a different setting. I have no doubt you've already looked into tire pressures (for some strange reason, I've noticed better fuel mileage results on all my vehicles lately when sticking to factory-range pressures... contrary to what I was always told. I can't say anymore than that for now *shrug*)

Plugs and plug gaps would also be a good thing to check out. Fuel filter, air filter etc.

One 'way out there' question: because the car is new to you, could it possibly be a case of having it idle more often and/or longer than you would your other MMs due to leaving it running while showing it to people? More lunch time drives with co-workers to show them the new acquisition (ie. more weight in the car in a city driving situation, thereby influencing the numbers)?

Or maybe it's a case of you being used to the shape of the supercharger's power band and subconsciously expecting the same performance off the line before realizing this isn't the same car? At first thought this may sound silly but in the end you've spent a heck of a lot of time behind the wheel of 1x. Driving techniques when behind the wheel of a specialty vehicle like the Marauder can become more visceral than logical (ie. we are more in tune with the vehicle than your average commuter). *shrug*

I say give it a few more tankfuls (after addressing some of the suggestions in the thread) and assess where you stand at that point. On a personal note, I don't consider that MPG result as out of this world, but if it happened to me I'd look at my log and most likely find something along the lines of 20-30 minutes idling in a shopping center parking lot with the kids in the car waiting for my wife to come out, or idling in my driveway for 15 minutes as I chipped away at ice, etc.

(oh, that reminds me, if this car is not garaged, as I assume 1x and it's predecessor were, the extra warm up time might contribute slightly to a dip in mileage as compared to the other cars).

[DEFYANT]

One 'way out there' question: because the car is new to you, could it possibly be a case of having it idle more often and/or longer than you would your other MMs due to leaving it running while showing it to people? More lunch time drives with co-workers to show them the new acquisition (ie. more weight in the car in a city driving situation, thereby influencing the numbers)?

Aay Mac, I think he's suggesting you have some fat cops where you work. :P :D

[cyclone03]

Mac you now as well as anybody that a computer tune is what you need.
My '03's first ,early, Dennis tune put me at 25 on the highway and 17 in stop and go traffic.

The new tune with Kooks and PI3000 and stock gearing gets as high as 28 at70-80 mph on the highway,(the converter does kill the stop and go mileage to your 16).

[TripleTransAm]

Aay Mac, I think he's suggesting you have some fat cops where you work. :P :D


:lol: Let me rephrase: when my MM#1 was brand new, I think I made every effort possible to take that car when going out for lunch with co-workers (whether heavy OR lightweight, LOL!) . At the same time, I was more apt to drive a little more aggressively to show off the exhaust note (which is a little harder to do with a stock exhaust AND the stock calibrations... things get real quiet once the TCC drags things down to 1000 RPM).

3 years later, still on stock calibrations and stock exhaust, I blend into the background of commuter traffic when on a lunch run. No out-of-the-ordinary launches, no high RPM upshifts, no manual gear selection, etc. And that's if I even want the hassle of taking my car out for a lunch run... I'll rarely turn down the opportunity to let someone else hunt for a parking spot and then worry about getting dinged or worse. So that makes for more tankfuls of purely 2 adults and 2 young children as passengers, no more. (and lately, just me in the car, as my wife is still on maternity leave).

Just thought of something else too... when I got MM#2, I quickly noticed how the car felt a little peppier than my first car. Before the snow fell, I spent a bit more time testing out the new car just because it was new to me and I was curious. No doubt a few months down the line, I'll be sticking to normal everyday commute type of driving... since I'll have satisfied my curiousity about how #2 behaves itself at different rates of acceleration. :D

That's why I'm thinking Mac's current winter MM won't take much to start ripping off average numbers (or at least numbers he's more comfortable with).

[O's Fan Rich]

Mac, That suckdidlyucks! On my worts days I get 19.
Heck My MM does as good as and often better then my winter beater 99 Subaru Legacy SUS AWD. (yeah, yeah, yeah..... I know.:baaa: )

Put a supercharger on it, it may do better!!!

[cougarmandan]

I am curous about you folks that has had the retune. How does that affect your performace? In my mind, better mileage, poorer performace.

[cyclone03]

I am curous about you folks that has had the retune. How does that affect your performace? In my mind, better mileage, poorer performace.

Thats what the "experts" preach.

The tune optimisise the timing/fuel and shifts to what give better performance(power) driven "normally" these changes help mileage because the driver "feels" a leval of performance at a lesser throttle opening,less throttle opening = better mileage.

Now I know that our resident tuner makes no changes to the tune below 3000 rpm and less than WOT but I got,and still do,get better mileage.

The 5.0 stangs responed to twisting the distributer the same way,better milage.We used to get 27 with our Automatic '89.

[TripleTransAm]

I am curous about you folks that has had the retune. How does that affect your performace? In my mind, better mileage, poorer performace.


After many years of putting fuel mileage under the microscope, I began to realize some things. I firmly believe that many manufacturers set up their vehicles to cater to certain mileage results in certain scenarios.

One of the first things I discovered was how my '84 and '85 Civics (5-speeds) were just so happy to operate at 55 mph. Anything slower was a waste of precious time, anything higher was a steady ever-rising incline of fuel consumption. With my '98 Civic (also 5-speed), I was expecting a bigger improvement and did not find it at at that speed... instead, I found a much bigger improvement by raising that speed to 60 mph. Coincidence? Or a sign of a car manufacturer catering to a greater tolerance of 60 mph (and higher) on our highways versus the stringent 55mph of previous decades?

And then my experience with the "computer-aided gear selection" (the infamous 1-4 forced-shift on low throttle acceleration) on my WS6 got me wondering: how can anyone drive normally like this and get good mileage? I'm one of the few morons who actually did not disable this system before 2-3 years went by. Once I disabled it, I realized that there must be a specific EPA test scenario that is addressed by this mechanism... and it must be a scenario so tightly controlled that it can't possibly mirror real life driving except for perhaps a 0.01% probability. I realize I get better city mileage by executing a 1-2-4 or 1-3-4 upshift pattern rather than a 1-4, but then again it's impossible to get a solenoid to force that type of shift instead of simply locking out 2nd and 3rd and 'grooving' the shifted into 4th.

What does this have to do with the MM? In many cases, I wonder to myself: with these stock calibrations, why in the world would they want to upshift to the point of bringing down the RPM of a motor that does not like to run at so low speeds, forcing you to press harder on the throttle? Larger throttle openings at lower RPM usually mean having to deal with the possibility of pinging so dealing with all this seems counterproductive to a good MPG figure!

Unless... you WANT to cruise at that speed and nothing more. Which is why I suspect part of the EPA schedule involves a steady speed around the point where the stock calibrations will shift. If the EPA wanted higher cruising speeds, no doubt they would have allowed the MM to hang at a lower gear until approaching that speed (as long as the speed wasn't too high, of course). Considering everyone I know gets 30+ MPG with their 4th gen F-bodies, why in the world wouldn't GM advertise this figure instead of 25 or 26 mpg? Because the EPA tests are probably at lower speeds, and we're all getting our 30+ at 70 mph.

Trickery for good city numbers? I hear manufacturers do a lot of things to pull off good numbers. I've read rumours about one company using a switch to detect when the car was on an EPA roller for a test and switch to an ultra conservative mode... what other scenario would a car possibly be in, driving at 55 mph or so with the hood up? ;) I've also heard of a 70s Pontiac with a timed EGR valve... ie. calibrated to be rendered inoperative by the time an EPA test should have been completed.


So this is the logic that makes me believe an aftermarket tune can in fact give you real-world improvements in mileage. Put your car on the strict EPA test schedules and it would not be so rosy... but I'm thinking those test conditions constitute a very small portion of a real world drive.

[O's Fan Rich]

I am curous about you folks that has had the retune. How does that affect your performace? In my mind, better mileage, poorer performace.

I stayed pretty much the same 21-22 mpg day to day 26-27 when I do alot of highway cruising. Now, that's being gentle , mind you.
I have the Flasher with Lidio'd setup from Alternative. I also have the K&N CAI. Otherwise, I'm stock. For now.

[Kenny's car]

When my Marauder was new, I got in the range of 15-17 mpg, after I used the programmer, mileage jumped to an average of 20 mpg (town), 23 (road, under 80mph). My thought is that the advance recurve boosted efficiency, along with shift point, and fuel curve recalibration. Of course chips do the same things, which may explain the difference between your hotted up Marauders and the stock car. The question is: is the payback in economy enough to justify the cost of the chip/programmer???

[TripleTransAm]

The question is: is the payback in economy enough to justify the cost of the chip/programmer???

At this point, I think the payback is more in driving enjoyment, although I can't say I know how much better an aftermarket tune drives, shift-wise. What can I say: I like the MM's stock behaviour, regardless of the bottom end complaints by some.

But there is one thing that I've been growing concerned about, based on what I've read about timing curves and RPM and load (and this is purely hypothetical at this point and highly subject to being completely disproven):

I wonder if the stock factory calibrations are contributing to the overheating we're seeing in some of our less-fortunate 'coolant-shrouded' cylinders (you know who you are!). In the old days, you had low RPM and high throttle openings on cars that shifted too soon which could result in leaner mixtures and more pinging due to a lag in the carburetor responding to the larger throttle opening, but with EFI you can have the PCM tune in the appropriate response. So I'm wondering if prolonged low-RPM high-load scenarios would result in higher cylinder temps and possibly a greater chance of munching our weak valve guides? Perhaps this is a reason why Ford is so reluctant to address the root of the problem? (ie. it would involve rethinking calibrations, which might end up busting their EPA mileage compliance?)

Of course this doesn't address the fact that some 4.6s tick while still in the showroom (I've personally witnessed two, back at the beginning of my anti-tick crusade in Oct 2003). But my original head did show evidence of pretty hot running back in those two cylinders, and I am now wondering if the calibrations are partly to blame?

I wonder if anyone managed to develop the tick a fair amount of time AFTER having aftermarket tuning installed? (then again, nothing says the aftermarket tune couldn't be responsible for the onset of the tick, so it's back to square one :( ).

[Warpath]

...I've read rumours about one company using a switch to detect when the car was on an EPA roller for a test and switch to an ultra conservative mode...

One of my internal combustion engines professors told us it was Porshe. Appartently they got caught and were repremanded according to him.

[jgc61sr2002]

The best I could get was 24 MPH on an extended highway trip. :D 75MPH at approx, 2200 RMP.

[Rider90]

The best I could get was 24 MPH on an extended highway trip.
You were not pulled over? :hide:

[bugsys03]

My MPG always sucked. 220 miles per tank in town(if I babied it), usually more like 200. Never ever got more than 21 MPG highway. Not that I"m complaining, didnt buy it for MPG, bought it to enjoy!!:)

[jgc61sr2002]

You were not pulled over? :hide:


No.never:D

[SergntMac]

Just dropping in here to say thank you. Thank you to you all for your commentary and advice.

Yes, there surely seems to be many Avenues I can stroll down, some are side streets, some are alleys, and others are Boulevards. There are many paths open to me, which is why this is so much fun for me.

I plan on taking this a bit slower than y'all expect. Right now I'm loaded up with a full tank of Citgo 93 octane with a pint of Seafoam added in. I also have another pint of Seafoam in the crankcase, and I'm about half way to my next oil change. I should burn three tanks of fuel before that, and I (and y'all) should know more then. Let's talk about that when we get there?

meanwhile, thank you again, for the advice and guidance. It's exactly what make this site rock!

[cougarmandan]

Back to retunes, I just filled up my MM and got 18.2 on this last tank. It would be nice to get 5 or so MPG better. But more importantly, I have noticed that unless you are getting on it, it shifts too soon. The 3 to 4 shift, so I thought, it way too big of a gap sometimes. I'll bet its a 2-4 shift. I am used to driving and AOD and an AOD-E and I can make them shift certain way by how I use throtle control, AOD's especially. If I use the same techniques on the MM, it always seams to result in it shifting too soon. I have been wonder if a shift kit would changed its shift pattern or if a reprogram is needed. Either way, I do think it could have been done better from Ford. Now, chips v/s tuning. I like the idea of keeping stock calibration at hand if I want to change it back. Any one want to sell me a cheep PCM so I can have it programed. What are the MM, EEC-V? Will any EEC-5 box work since its getting new program or chip?

Now, Math is my forte. All those dang collage math classes I took and never use more than Algebra. Anyways, break even point as I figuar it. I don't know what it costs for a reprogram since I have never done it, but I would guess its in the $200 range, someone correct me here. Gas I bought 2 hours ago was 91 octane for $2.50 a gallon (makes the math simple here) We'll use an improvement from 20 MPG to 25 MPG, which also makes for easier number to work with here. Here's how it goes:
$2.50 per gallon and 20 miles per gallon means
2.50/20= $0.125 per mile- which mean it cost 12.5 cents in fuel to go 1 mile. Now, if you improve to 25 miles per gallon at $2.50 a gallon
2.5/25- $0.10 per mile- it only costs you 10 cents to drive a mile
the difference is 2.5 cents ($0.025) so it saves you 2.5 cents every miles you drive. If it cost $200 to get the tune, then you divide 200 by 0.025 and you get 8000, which is the miles where you save $200 bucks. If you drive your car like a normal person does and put 12000 miles a year on it, it will take you about 9 months to recoupe the cost. To put that in perspective, if your wife gets pregnant tonight, by the time the baby is born, your chip has paid for itself. At least, that's how it looks to me. Anyone see any flaws in my math?

[TripleTransAm]

20 mpg to 25 mpg seems like an awful huge improvement. If this is the case, I swear I'll physically beat anyone who stands in my way as I run to the nearest tuner.

As for the shifting... yes, it's indeed a 2-3 shift, not 2-4. It just feels that way because you go from 2nd gear with the torque converter clutch slipping at 50-60% (makes me cringe just typing that) to 3rd gear with the TCC locked up 100%. Initially I thought it felt like an early 2-3 shift when the TCC went from 0% to 50-60% and the large RPM drop was when the TCC went to 100% in third (as it does in my GTA) but nope, Autotap confirmed it stayed in 2nd until 40-ish kph (25 mph?).

Don't bother with the spare PCM, a handheld tuner unit will swap out your original programming which you can always re-download whenever you wish.

Edit: my MM#2 appears to be hovering around the 18 mpg mark, with one 17 and very few 19s. At first I didn't think it was that great, but comparing with other winter results with MM#1, it's more or less on par. Perhaps ultimately a little better, since I seem to be having a bit more fun with MM#2 since I don't have to lug around my whole family every day like I did last winter.

[Marauderjack]

I have been checking mine since the blower install and I seem to have lost about .5 MPG in town and about 1 MPG on the highway!!:rolleyes: I don't get into boost every time I accelerate...In fact the car is so responsive that on a 400 mile round trip last Saturday I reset the boost gauge and never got above 3# all day long!! Mileage for that one was 21.5 up and 23.7 back....average 22.6....Not bad at all running about 75 MPH the whole trip!!:beer:

When I was running with just the SCT tune I averaged around 23.5 MPG on the highway!!:)

Mac.....I will be interested to hear waht you think about Seafoam treatments.:cool4:

Marauderjack:pimp:

[cougarmandan]

Well, the reason I used 20 to 25 is that its somewhat close to reported result and it works out really nicely with the math, meaning, you don't have to carry it to 47 decimal places. However, if the tune is twice as expensive or the improvement only half as good, then it will take twice as long to recoupe the investment, or if both scenarios are the result, then it will take you 4 times as long which is 3 years. Thats if you are looking at it strictly as an investment situation, which you shouldn't. It just farther justification for someone if they need it. Where do I go to find the SCT tune?

[rayjay]

Well, the reason I used 20 to 25 is that its somewhat close to reported result and it works out really nicely with the math, meaning, you don't have to carry it to 47 decimal places. However, if the tune is twice as expensive or the improvement only half as good, then it will take twice as long to recoupe the investment, or if both scenarios are the result, then it will take you 4 times as long which is 3 years. Thats if you are looking at it strictly as an investment situation, which you shouldn't. It just farther justification for someone if they need it. Where do I go to find the SCT tune?

There are too many variables that can affect MPG. City v highway driving, idle in traffic time, personal driving habits... I started seeing MPG improvements when I had my car dyno tuned last summer. Gained +4 MPG immediately. DR Cobra exhaust and GMS COP Connectors have also gained improvements for me.

['03BlkMM]

I've seen and participated in these MPG threads before. One thing I have concluded is that its worthless for different people to try and analyze their city MPG results. There is such a wide variety of differences between how different people drive and where they are driving, i.e, how many stops, steepness of grades in your area, how much idling time in the McD's drive thru, etc, etc. That there is no way you can say that your city mileage is bad compared to another members mileage that is 2 MPG better than yours. If those 2 members were to swap cars for a tankful of gas. They are very likely to find out that they get the exact same or maybe even worse mileage than their own car and that car supposedly got better gas mileage! The best you can hope to compare is highway mileage and even that can have a lot of variability, but can be a little more exact if you know the circumstances behind how/where that person was driving during that test.

My friends and I were comparing our F-150 gas mileage the other day at work. They were all shocked to hear that our 2000 F150 extended cab with a 4.2V6 only gets around 13.5 mpg. But as I explained to them. Its almost exclusively driven around town. It almost never sees the highway. It rarely ever goes over 50 mph and probably never goes more than 1 mile without sitting at a stop sign or light. It also sees quite a bit of idle time in drive thru's. Once we got to comparing the differences in driving, my friends '05 F150 5.4L that was getting 15 mpg on average didn't sound so great anymore. He spends probably 60% or better of his time on the highway driving to work. In that same scenario my truck would probably get as good or better than his. But, he still considers that to be city driving.....

Now for sergntMac whom is comparing his own 3 cars the results can be a bit more exact as he is the one running the tests between cars.
It doesn't really sound like yours is too bad Mac, the original EPA estimates were 17city and the EPA city test is a very conservative test for city driving. I saw the criteria for the EPA city test in an auto mag a couple of years ago and they even stated that most people would be lucky to ever attain the city MPG results the the EPA sticker lists...

[SergntMac]

Thanks, '03blkMM. What you say is true. I am comparing my present MPG performance to my other MM experience. Besides disappointing MPG (in comparasion to my other cars), it also runs hotter. Average engine temp is 198 to 210, and I know this is not ideal for combustion, but it is ideal for emissions. One more way to confirm thatb this MM is really bone stock.

I tried something on the way home from the office today, on my all city street course. I took a common door stop and strapped it to the bottom of the accelerator, to fashion my own self-imposed govenor. No matter what, I could only apply just so much throttle, just about a quarter throttle if I guess correctly. This allowed me to accelerate from a standing start at a comfortable pace, and let the factory shift schedule show it's stuff.

I accelerated into and stayed with the flow of traffic, no problem. By the time I hit 4th gear (OD) and the torque converter locked up, I was cruising at 35 MPH, at 1300 RPM and I got there in about 45 seconds.

There were many ocassions where I had to lift off due to traffic, however, to achieve a city street cruise mode at 1300 RPM, well, IMHO, this is a very conservative schedule. I have also noted that this particular MM reacts very well to initial throttle, as if it had 4:10s, but I have confirmed that stock 3:55s are in place. BTW, I've traveled 55 miles since my last fill-up, and the fuel tank needle is still on Full, that's new, eh? Yes, '03, 16 MPG isn't far from the EPA prediction, MPG is all personal right foot.

My Kenny Brown car gets 19-20 city, and 22-24 highway, with 500+ RWHP...Why? For one, it's chassis tuned to maximize forward roll and minimize friction and resistance. I'll bet my KB car can coast twice as far as any of y'all. Second, it produces a lot more power in lower RPMs, therefore, it doesn't work as hard to accelerate and overcome the drag of 4400 pounds of dead weight from a standing start. With mods like a highly efficient Stallion torque converter and 4:10 gears, more power is on duty with less throttle, and as long as I control my right foot, my MPG should exceed the EPA's program. That's awesome, wasn't like this when I was a kid.

The one thing I'm having fun with right now, is planning the MPG improvement. I've asked Zack to run through the SCT/CRD1 programming, to see what he could tweak in favor of MPG, and just to see what can be done. Then, I'm going to take a hard look at some other ideas, some of which have been posted here already, and some of which are my own perceptions.

My goal, is to see 25 MPG city, 30 highway, without a reduction in bone stock power. You may be thinking "hopeless" right now, but I've got to give it a shot. My "oddball" approach here, is how I enjoy modding my MM, what is there to lose?

[TripleTransAm]

So you've got a CRD1 now? Welcome to the club.

Your observations about off-the-line response are exactly what I've been experiencing with my second car, however I'm going in the opposite direction (used to a CRD1 car, now experiencing CRD0 calibrations). Not having experienced 4.10s, I couldn't claim this car had different gearing but the thought did cross my mind. However, all RPM/MPH (or kph) comparisons work out between my 2 cars, so I'm sure it's still got its 3.55 gearing.

Funny enough, I've also noticed what seems to be a slightly warmer operation on this second car, but I wonder how much is due to simple gauge sloppiness. This second car points just a needle or two's width above the 20 mph mark (harder to tell on a metric speedo) whereas the first car sits pointing right at 20. However, Autotap confirms my operating temperature is right at what's been indicated here as the factory t-stat setting. Was my 1st MM operating a hair colder? I'm trying to find old logs to see if I bothered to log coolant temps, but have not been successful so far. Nonetheless, factory t-stats are sloppy to begin with, pick up two identical t-stats and you can see a variance of 10 degrees, I'd be willing to bet.

I'm almost 100% certain MM#2's CRD0 shifts into OD about 2-3 kph earlier than MM#1. Again, speedo error might mislead, but the 2-3 shift occurs exactly as with MM#1 and Autotap results seem to indicate a shift point that I would have probably remembered with MM#1. In other words, I always thought MM#1 shifted into OD at 60 kph or a hair above, whereas 57-58 kph upshifts are the norm with MM#2. MM#2 doesn't fall on its face as hard when this happens, either... calibrations? Lower accumulated miles on the drivetrain? Luck of the draw? Looser engine due to harder life? No idea, but I like it.

My fuel gauge has also misled me to some extent. While the drop off from Full occurs more or less at the same time, the rate of travel to 3/4 isn't quite the same, maybe 10-20 miles off on an average tankful? Halfway seems to be about the same, but I've noticed that when the Low Fuel light comes on I have close to a gallon less than what I'd have in MM#1. I haven't experienced any "Oh Crap!" moments, but I'm glad I didn't take any chances.

About tweaking for max economy: one thing to look out for is excessively lean highway or cruising mixtures. Some F-body guys tapped into some time-based 'lean modes' and subsequently melted catalytic converters in no time. Got silly high MPG numbers before it happened, though!

[FordNut]

Found out the fuel capacity today. Coasted in to the pump, held 19 gal. I've been pushing it a lot, since many of my fillups are 18 gal.

[Rider90]

Found out the fuel capacity today. Coasted in to the pump, held 19 gal. I've been pushing it a lot, since many of my fillups are 18 gal.
Yep, FoMoCo says 19 gallons too in the 04 brochure

[TripleTransAm]

I don't think the stated fuel capacity takes into account the filler neck, which can actually hold a good deal of fuel. I think I've also noticed that the less fuel in the tank at the time of the fillup, the easier it is to fill the neck up with fuel.

I began to realize this in December 2004, when I went to go fill up my WS6's tank before putting it away. 16.3 gallons later, I had filled the tank up to the point of seeing the fuel level remain constant through the filler neck opening. This was alarming because the stated capacity of the tank is 15 or 15.5 gallons, I forget. And I can tell you my tank was NOT empty at the time of fillup, as I am greatly concerned about burning up my fuel pump.

My initial thought was fraudulent activity at the station, but since then I've seen this 'overfill' condition at every other station at every fillup situation, with all of my cars. Seems that it's one thing to fill the neck up to seeing the fuel level rise with your own two eyes, but if you then wait 10 seconds or so, the fuel level will suddenly begin to descend. I think this is due to bubbles being 'burped' from inside the tank and allowing the level to drop. I've crammed in an extra 1/2 gallon into my tanks on a regular basis by doing this.

Downside is, you have to do this every time if you want reliable MPG numbers, otherwise you will fudge the results.

[SergntMac]

Learned something interesting this morning. First, I stopped for air, bumped the tires to 40 PSI. Then I left the Traction Control on (default) Overdrive on(default) and door stop in place. Then I took the expressway route to the office.

The car has enough acceleration to merge into the right lane without being a pest to others. The speed limit is 45 MPH in this construction zone, and I was able to reach 47 MPH.

Having 225/60-17 at all four corners, the Traction Control didn't throw a fit until I came to the I-57/I-90 merge where a long bend in the road changes your direction from east to north. I must be right at the threshold at 47 MPH, the bend was enough to trigger the Traction Control. But once I straighten out, it went back to default.

[James96]

04 Marauder Excalty 20MPG All Highway set cruise @ 75mph

[SergntMac]

Mac.....I will be interested to hear waht you think about Seafoam treatments.:cool4: Marauderjack:pimp: In a word, Jack, I'm impressed. To recap things, I started out with an informal MPG test on my new-to-me #3 Marauder, I observed 16.8 MPG without making any adjustments to the car at all. Then, I adjusted my tire PSI to 40 all around, and went ahead in round 2. I added a pint of Seafoam to the crankcase, and a pint to the gas tank. Today, I filled up again, and I am pleased to report an improvement to 17.9 MPG. Remarkable.

Now, can someone tell me if this Seafoam treatment is something I should do always, or, just every so often. Adding the Seafoam brings my dipstick to the upper full mark, do I add this to the crankcase every change? Or just to clean up, like maybe twice a year? Likewise as a gasoline additive.

BTW, Thanks, Jack.

[Vortech347]

All city driving with alot of barking 2nd gear. 17.2mpg yesterday.

[jimlam56]

In a word, Jack, I'm impressed. To recap things, I started out with an informal MPG test on my new-to-me #3 Marauder, I observed 16.8 MPG without making any adjustments to the car at all. Then, I adjusted my tire PSI to 40 all around, and went ahead in round 2. I added a pint of Seafoam to the crankcase, and a pint to the gas tank. Today, I filled up again, and I am pleased to report an improvement to 17.9 MPG. Remarkable.

Now, can someone tell me if this Seafoam treatment is something I should do always, or, just every so often. Adding the Seafoam brings my dipstick to the upper full mark, do I add this to the crankcase every change? Or just to clean up, like maybe twice a year? Likewise as a gasoline additive.

BTW, Thanks, Jack.
I use it twice a year on all my vehicles, and have for several years. Good stuff!