MPG Still Sucks at 4500 Miles

[engine23ccvfd]

Guys hope you can help. My MPG has not increased one bit since i got my MM. Currently I average 13.7 MPG. I generally drive 20 miles a day at 80 MPH and 17 miles daily in city driving.

I do a daily WOT getting on the freeway which I am sure sucks some gas but I feel I am off some how. Any ideas?

Do I need to give break in more time?

Thanks

Andy

[Jeff]

That does seem quite low. I drive a similar pattern to you during the week and get 17 MPG / 20.5 MPG cruising 78 mph for my weekly 217 mi. trip home.

With 5500 miles on her I've always used 93 octane and first oil change with Motorcraft 5W20. I keep my tires @ 35lbs.

Dunno...:confused:

[TripleTransAm]

Quite a few MPG complaints... I saw someone (RC?) bring up the axle bearing TSB in another thread about a noisy rear (no Mexican food involved either, apparently) and I'm wondering if these MPG issues aren't related in some way to excess friction on some of the cars for which the TSB would be applicable?

At the very least, perhaps a quick alignment check to prove that there isn't a wheel that's tugging too hard in one direction and soaking up all kinds of road horsepower.

[studio460]

Dang, Engine23 . . .

I average almost the exact same thing. I drive 22 miles highway @ 74MPH/18 miles city on a typical day. I inflated my tires to 38 lbs. I'm STILL getting what you're getting . . . 13.4-13.7 MPG!!!

[Marauder57]

My mileage is about 17ish with City driving.....the one time I did a lot of highway..it was closer to 20....but sometimes city is just not so great....but in truth I did not by this for the Gas Mileage.. :D

[cyclone03]

Well NBC shooter has an excuse,reformulated gas.
I don't know about Houston.
When we were in CA back in Mar. I noticed a drop in milage.

[LincMercLover]

Doing 80 does not help MPG. Anything over 75 with this car and you can notice the MPG drop, and doing that WOT every morning is sucking some too. City driving of course is hell on MPG. So, I think you're probably doing about right with what you're doing with the car. I average 17-20MPG with mixed driving and 7000 miles on the odo. Check your tire pressure (mines at 35 front 32 rear) and try to cruise at 75 on the way to work, see what that does for ya.

[engine23ccvfd]

Uhggg 75 there must be abother way.....Houston does have the reform gas. Cant remember if its just the summer or all year now. Shouldn't that crap run cleaner and more effeciently?

In the interest of science I will try driving slow one week and punish myself.

[Logan]

My mileage was always between 17-20... I would take it in and get it checked...

[looking97233]

I just had my PCM flashed. Cured the rough start/ surge problem. Runs smother now. I remember a thread citing a TSB on this, it said the program was making the motor run rich. This was causing plugs to foul. If this is the case, wouldn' that have a large inpact on feul milage? I was gettin about 14-15 mpg from mine, mostly city driving and I have a weighted foot. However on my one long trip with the car, I got 24mpg over 400mi. on the highway. I will check gas milage now with the new software.

[beemer]

During CVN's recent St. Thomas trip, for one leg of the return I got 26 MPG out of the Marauder. It now has 2400 miles.

In mixed driving it has been consistant at 20MPG. I've really got to hit the loud pedal to reduce the mileage below 20MPG. I am quite pleased, as the 2001 CV LX Sport I had previous was hard pressed to show me at best 17MPG.

Best,

Paul:D

[sailsmen]

I get 15 in the city and 19.5 on the hwy doing 75-80.

[Matt Johnson]

I hover around 13 mpg with 4700 miles on the clicker now. LA city driving, lots of starts and stops, jumps on and off the freeway, and I've got a very heavy foot.

Just took her to Las Vegas for two days this week and noticed solid MPG increase to about 19 MPG and that's with the cruise control at 85 MPH.

Not too concerned about gas milegage, but I am driving a car that has never had any software updates, has never seen anything but 91 octane fuel, has no mods, and has not been back to dealer since I bought it (I pulled into an LM dealer to have oil changed at 3000 miles, overheard a mechanic ask a co-worker "What is that?" so I pulled out and drove to EZ Lube).

[amerikan]

i just took a 500 mile trip to sacramento from southern california.. i got an average of 23.7 MPG going around 75.. ive heard that the sweet spot for gas mileage on this car is around 2200 rpm.. so around 72-75.. and.. a/c was on the whole time.

[WolfeBros]

I ran 600 miles last week with 4 adults and suitcases in the car, doing 72 - 75 mph......some 80 and I averaged 23.1 MPG. Now thats in Texas where the road is relatively flat. But I concur with the sweetspot......my car loves 2200 RPM.

[studio460]

Well, Matt, Cyclone . . .

I guess I'm not alone on this poor L.A. mileage issue. Cyclone--what exactly is different about California gas other than the low 91 octane? Someone here had mentioned that MTBE-additive fuel lowered mileage--I was under the impression the opposite was true, that ethanol-additive fuel lowered mileage (or horsepower), so I've been avoiding ethanol pumps (e.g., 76, Arco) and favoring MTBE pumps (e.g., Mobil, Chevron). I tried a tank of 91 octane Texaco for the first time last night . . . will see if there's any change to report.

[TripleTransAm]

This is maybe a wild goose chase, but how much extra cargo are folks carrying around, when they complain about gas mileage? I know it'd have to be a heck of a lot of cargo to carry around to impact mileage this badly, but I did know folks who carried complete toolboxes (the LARGE kinds) around in their trunks... one relative loaded down his 1978 Fairmont so bad that the rear end was practically dragging, and acceleration from the 302 2Bbl was painful, and this practically from the day he bought the car!

Another thing I've been wondering... I had a brake booster that was 'lazy' in releasing the brakes, to the point where the brake lights would actually go off if I lifted pressure off the pedal in any way. Maybe these low gas mileage cases are related to lazy boosters in a more extreme case? Might be something to check out... riding with your brakes semi-applied will soak up lots of power and mileage.

[TAF]

Originally posted by NBC Shooter
--what exactly is different about California gas other than the low 91 octane? Someone here had mentioned that MTBE-additive fuel lowered mileage--

I don't know what the real story is...but, it would NOT be too difficult to imagine that politics would create a gas that would need to be used more (less MPG) to supposedly reduce emissions. So everyone uses more gas...then someday they say "Well, we THOUGHT we were reducing emissions...but..."

[cyclone03]

Oh wow,I wish I knew were to start...............
First I'm no expert on petrolium products.

I few years ago the tech editor for MotorCycleist Magizine wrote a VERY Long article on what is going on in CA with fuels.
Art Friedmen I believe was his name.
MTBE,Gasahol, and what seemed like 100's of other additive all in the name of helping clean up the air. Most have negitive reactions on other parts of the enviroment.
He's no crack pot either has lobbied and appered as an expert witness on many cases against the use of many chemicles used in CA.
I use the past tense because I think we lost him about 2 years ago...........


Truth is i don't know what was in the gas I put in my car out there,I also drove the car very easly because Im cheap,trying to maximize milage.But per gal. the fuel in CA has less energy per gal than Gas in other parts of the country.That has been said by many people for several years.

[engine23ccvfd]

IN Texas five counties around Houston and I believe some of the Dallas/Ft Worth metroplex are required to use the re-formulated gasoline however it does come in three flavors which i believe is 93 oct, 89oct, and 87oct....I went to one station (Texaco?) that had 91oct as its middle gas.

As for additional weight i dont carry much in the trunk. Gallon of water, gallon anti-freeze, quart oil, can flat be gone (extreme emergencies only), and 50 lbs of fire gear. I am a lean 150LBs so my cargo and body doesnt match some of all with a little extra padding.

I wonder if a emmisions(SP) test could tell me if I am passing more unburned fuel than I should? What about a dyno? I dont mind spending a little extra on gas but crap I get near the same as my big v8 Dodge Ram (5.7 liter I think)

[RF Overlord]

Originally posted by engine23ccvfd
I wonder if a emmisions(SP) test could tell me if I am passing more unburned fuel than I should? What about a dyno?

I don't know the emission testing standards in the Lone Star state, but here in MA, the emissions test only reports the 2 or 3 factors they're interested in, and the ranges are fairly liberal.

A dyno pull is an excellent idea as it will not only tell you your A/F ratio, which may provide a better clue as to your mileage situation, but would also provide you with a good baseline should you ever decide to do any mods...

[joflewbyu2]

i drive 22 miles each way going 70 - 75 mph with 5 - 6 stops at traffic lights. go 325 miles before fill up that takes 17.5 gallons. average about 19 mpg. car has 7,000 miles and motorcraft 5w-20 oil.

[prchrman]

93 octane...mountain roads...over 20mpg all the time...over 23mpg when not being a leadfoot...chirp chirp...

[duhtroll]

Funny - on my work weeks I average 21, but on long trips where I have extended periods at higher mileages (80-85) I get 24.

My work driving is 95% highway, too. I rationalize going 80 because it saves gas . . .. :)

In town I get about 19.

-A

[studio460]

Thanks for your input, Cyclone. I guess I'll mark it up to California gas. Like I said before, I only got 12-13mpg in my 2000 V6 Mustang! BTW, I have two large tripods, a couple of titanium drivers, an iron, a putter, and a spare tire in the trunk, plus me, at 178 lbs. Not that much, really . . .

[engine23ccvfd]

OK guys thanks for the info...How much can I expect to pay for the Dyno testing?

[RF Overlord]

engine:

I don't know what things cost deep in the heart of Texas, but generally expect to pay somewhere around $80 an hour...for your diagnostic and baseline purposes, an hour should be plenty.

[MAD-3R]

In this area, I got 3 pulls, with A/F Ratio's done for $100.

[RF Overlord]

^^^what MAD said^^^

The dyno time for my FordChip tuning was $100, but there are relatively few dyno shops in New England, so I a$$umed the service would be a little cheaper in other places where there may be more shops and greater competition.

[TAF]

Find you a local SVT Ford dealer. Most of those have in-house Dyno equipment or connections with a local Dyno location. SVTOA members in ATL can schedule Dyno-runs at our "host-dealership" for $65.

[engine23ccvfd]

Great thanks for the info...my closest SVT dealer is a decent drive from the house but I do have a High Perf shop in the area I better they have one....I think they are called Houston High Performance on Cutten Rd?

Off to San Fran for the Fourth ya'll have a great weekend!

[drkknight196]

If my mileage was that bad, I'd be knocking down the door at L/M! My odometer now says 17K. I drive pretty aggressively and lock on at 83 on the Interstate. I average 18 and have gotten as high as 22 highway. Something's definitely wrong -- IMHO.

[Glenn]

I got my MM last week and the first tank of gas with my foot in the floor was 16 mpg. The second tank of gas with about 1/4 of the time in the floor was 20 mpg with 93 octane. The 93 does make a difference. This car is a kick-ass to drive.

[TripleTransAm]

Took some time to update my mileage spreadsheet. I had to downsize it to be able to upload it but the jist of it is that I've got US MPG plotted against kilometers to date, from the purchase at around 30-some kms (due to test drive by myself, car was at 17km before test).

Looking at the trend, I've got two spikes, one corresponding to a 2 hour highway trip, and another with about 4 hours of highway on it but loads of traffic later on. Lowest point is low low 17 mpg, and that was immediately after the fateful trip in which my MM got its harness sliced and needed to be towed back home (ie. lots of time starting/stopping at the dealer).

So if I had to eyeball an average, I'd have to say I see a lot of 18s and 19s. This is comprising of 80-90 miles daily, getting stuck in a lot of traffic (sometimes at several places as I weave in and out of the city thanks to daycare situation ie. my parents). A/C is usually on, radio on, never use cruise control, and no particular attention to econo driving. 2 adults, 1 20 month old, misc cargo (laptop, etc.) and not much more. There are always the occasional blasts from a dead stop or WOT passing manoevers or times when I carry five adults (myself incl.) to lunch, etc.

FYI: It's a Canadian 300A (equiv. to US 300 B), build date 02/13/03, PCM s/w at CRD1 with original calibrations, tires at 33 psi, no mods whatsoever.

(I gotta add that the mid 17 mpg results early in the curve are with 94 octane... kinda confirms what I once posted about the lower BTU of higher-octane ethanol-enhanced gas)

[SergntMac]

Around Chicagoland, dynos are fairly standard. 125 bucks buys you one hour or 3 pulls, which ever comes first. If things go fast, you may get more pulls. I got as many as six at one shop, but we were looking for a problem more than measuring performance.

[mad man]

Just put 1600 on the girl 26 mpg cruz set at 70 Happy Happy Joy Joy .She's at 3200 now:)

[studio460]

11.65 MPG/city Texaco 91 octane (unknown mixture)/OD-off.
19.20 MPG/fwy Chevron 91 octane MTBE 74.5 MPH/OD-on.

[jgc61sr2002]

I got 19 miles per gallon around town. Quite satisfied with that.:D

[TripleTransAm]

I just got back from a car show I was photographing. My wife and my young son joined me, plus baby bag, plus big camera bag with camera, monopod and a half-dozen lenses. I filled up on the way there, and once I was in the vicinity of home... so mostly highway mileage (with one small exception, noted below).

I made a quick mental note of the approximate numbers, but it looks like I'll be posting a 27.x MPG run on this particular drive. WOW. (I have to get the exact numbers from my receipt, but it will definitely be above 27 mpg).

Conditions: really hot. REALLY hot. A/C was chugging along the whole trip. Total distance driven was about 118 miles and it consumed a little under 4.3 US gallons. It was about 98 % highway at a steady 62-65 mph, with about two 3/4 throttle passing maneuvers. Not flat terrain, but not too hilly either. About 2 % of the distance was backroads at between 25-50 mph. And I was forced to idle about 10-15 minutes in the parking lot of a grocery store so I could keep the A/C functioning as we made sure my little boy was properly hydrated after a few hours outdoors, before leaving for home. Oh, and just over 6200 miles on the car.

Un-freaking-believable! 27 mpg! Can y'all sense the shock I'm going through??? :banana: :banana:
I know 4.3 gallons is not an appreciable amount of fuel over which to calculate consumption, but I'm sure this car is capable of clicking off 25+ mpg on highway runs.

As if this wasn't enough, the trip seems to have opened up my exhaust some. The car now has a beautiful bark (it's been getting more growl-y the past few days)... I stood in my driveway and flicked the remote starter about 6-7 times just to listen to it fire up! :coolman:

[RF Overlord]

Originally posted by TripleTransAm

Un-freaking-believable! 27 mpg! Can y'all sense the shock I'm going through???

As if this wasn't enough, the trip seems to have opened up my exhaust some. The car now has a beautiful bark

3TA, I hate to say I told you so, but:

WE TOLD YOU SO!

:lol: :banana: :beer:

[amerikan]

NBC SHOOTER!!! ur crazy man. 11 MPG.. someones has a heavy foot :p but thats good

[Lowell]

9700 miles-14 city 21to 24 highway. Make cetrain that you patiently top off your tank before and after, for an accurate reading. Foot on the floor daily It's fun to hear a good V-8 isn't it? I am getting new wrinkles from ginning too much.

[Marauderer]

Guys,

The dyno pull is a good idea, but a typical dyno pull is done in third gear at WOT. Your A/F is going to be different under these circumstances than under cruise. Make sure they do a run that simulates cruising at different speeds. My car (as should be normal for any of our cars) tries to maintain a mid 14 at idle and in cruising situations, but is all over the place at WOT (tries to hit 12.2 but leans out to the 10's in the upper RPM's).

A cheaper way to tell if your car is running really rich is how often you have to clean the soot off the exhaust tips.

Bad gas mileage could also be caused by a bad alignment, low tire pressure, sticking brake caliper, cheap gas, etc.

BTW - I seem to get about 16 - 18 MPG in mixed driving, haven't taken a long enough trip yet to test purely highway driving, will report back after Thanksgiving.

[BillyGman]

I know this is an old thread, but there are two things I've noticed here. The first is for engine23. I don't believe you've listed what octane you use. If you don't use 93 octane, perhaps the lower octane will cause worse gas mileage.
The second thing is how NBCshooter listed his gas mileage readings being so different w/two different brands of gas. But allow me to state the obvious here by saying that it wasn't the brand of gasoline that gave you such different gas mileage, but it had everything to do w/the fact that you left the O/D off for one tankfull while having the O/D on for the other. (did I read that right?). Ofcourse you'll get much poorer mileage w/the O/D off. Getting better gas mileage is one of the reasons for having O/D in the first place.

[jgc61sr2002]

Originally posted by Lowell
9700 miles-14 city 21to 24 highway. Make cetrain that you patiently top off your tank before and after, for an accurate reading. Foot on the floor daily It's fun to hear a good V-8 isn't it? I am getting new wrinkles from ginning too much. Lowell - Your gas mileage is average. You can't ask for more than 24 MPG on the highway.:D

[TripleTransAm]

Gman, you confused NBC Shooter's post with mine... I didn't list results with two different octanes, he did.

I'm fairly confident that fuel mileage has a lot to do with the additives that are part of the blend of fuel, many of those additives being present in order to enhance the octane (there are several approaches).

My mileage-master fuel (92 octane Esso) recently went the way of the do-do, being replaced by a new 91 octane product as a result of cleaner refining processes (less sulfur content). They had different alternatives available to enhancing the octane back to 92, but decided against them all as a result of budgetary constraints. (heard all this from an employee with 'connections').

While I shouldn't be seeing a mileage drop with an octane drop (if anything, one would imagine the higher octane fuel being more resistant to burning), I sometimes got the impression the new 91 Esso stuff didn't give me the mileage their old 92 used to. Most likely a result of the different blend? In any case, I did notice a little audible pinging now and then with the 91, so I've since switched to Petro-Canada's 94 octane.

After my cylinder head was replaced, I began to notice lower-than-usual fuel mileage numbers, and thought maybe I was taking a hit with the new head. Turned out it was just my driving style that had gone down the *****ter, and once I went back to taking it easy, looks like the numbers are back to normal (19-21 in mixed driving).

One thing I have noticed... this car does not like idling. This will definitely hurt the mileage for that tankful (more so than my other V8s). Also, as I mentioned many many months ago, seems like ~60 mph is the best range for highway mileage. Makes a heck of a difference from cruising at 70-75.

Also, while it may not be as much fun, in urban stop and go traffic it pays to keep the RPM below 2000 on launches, and let the upshifts and torque converter clutch application "pull" you up to speed. I've also tried to get it up into 4th gear ASAP and keep the engine RPM at around 1200-1300, in dense urban driving.

Not fun, I know... but it's a necessary compromise when one is trying to save up as much as possible in a short period of time to fund the purchase of an upgrade in living quarters...

[BillyGman]

yep, you're right. I was thinking of NBC's post. I just edited my post. Good catch........and perhaps you're also right about the octane/gas mileage thing.;)

[Lowell]

I am very happy with the fuel consumption.

[Jeff]

I just glad to have gas mileage. :D

[beemer]

LOL I'm a late contributor for this thread.

Coming back from St. Thomas Ontario from our annual CV.net pilgrimage to the Ford plant and the Most Excellent St. Thomas International dragway, I found with cruise on and set at 75 MPH the Marauder returned 26 MPG on the NY Thruway, gassing at whatever Mobil? was at the Thruway service areas.

I was impressed by this, as my former 2001 Crown Vic Sport's best #'s were aprox 17MPG.

Best,

Paul:D

[TripleTransAm]

So whadda ya say, folks? Is the annual St.Thomas visit a good reason to have a Canadian Marauder roundup? C'mon guys, I'm getting lonely up here...

[Dr Caleb]

Me too. I could make St. Thomas in 3-4 days driving (I've done Edmonton -> Toronto in under 2 days) , but Darlington or Bristol will take me the better part of a week. Each way...

[marauder307]

Routinely get 17-17.5 mixed driving in town. St. Louis, and MO state I think, have a mandate for 10% ethanol in their fuels. I mention this because my mileage has dropped off slightly since moving up here, and FL and AL don't carry the ethanol. There is Phillips 66 place 'bout a mile from home that sells racing fuel for about I usually get the Costco 93 octane, but ever so often I'll run out a tank and refill with FuelMan (now Shell) 93 octane.

[deerejoe]

Canada
St. Thomas< < < < < < wherever....2004 Marauder Round-up:
Caribbean

If its (St. Thomas) in Canada, that will require about a 3 day drive.

If its (St. Thomas) in the Caribbean, that will require some serious marine type mods and a quick course on celestial navigation.

Please advise, ASAP!!