Yikes! 16MPG - Bone stock - 30K miles

[Mote]

The What's Your MPG thread is going on now - And I just finished a tank and I am getting just barely 16MPG - My car is stock (yeah I know, I need a TUNE!) and I drive 70% city 30% highway. I drive medium aggressive. Seems like I am at least a couple MPG from average. The car (seems to) runs great, is way clean - What could I look for?? Should I be concerned? I guess I am...

[B.C. Bake]

FWIW. I ganed 1mpg On just an oil change + air filter every 3000 miles or about 6 months.:rolleyes:

[dohc324ci]

That's what I am averaging on my 5.3L BBS 15-16MPG. But again its new sow a heavy foot may be dragging that down..LOL I am looking to get 16-17MPG I would be happy with that. I averaged about 17-19MPG stock...

[Blk Mamba]

Right now there is freeway construction on my way to work, so I do the 12 mile drive on city streets , two school zones, otherwise 40-45 mph, and I filled mine at 309 miles, 17.6 gal.

[Mote]

So what could be wrong? What could I look at?

[imorb1994]

I drive medium aggressive.


So what could be wrong? What could I look at?
Thats most likely is the problem. The cars get great mileage for thier size on the highway, but in town not so much.

[fastblackmerc]

If you want better gas mileage get a Prius..............

[Marauderjack]

"Winter Fuel Blend" ain't helping you either!!:shake:

[Stranger in the Black Sedan]

Sounds normal. I have gotten as low as 13 mpg city on a stock MM with only a tune, if it was all very short trips with lots of acceleration. It's a heavy car with a small V8, I doubt there is anything "wrong" with your car. You also have to remember that when people claim mpg online a lot of inflating goes on, rounding up, because it becomes a pissing match of, whose mpg is supposedly better.

[mrjones]

If you want better gas mileage get a Prius..............

I was filling up Sunday in the Durango, and I would've gladly changed places with the Prius driver next to me then! He spent $18 and I spent over $50!! I know the Prius wouldn't pull my motorcycle trailer, but the mileage would be nice.

On a more positive note, the Ford Fusion won Motor Trend's Car of the Year.

[Bluerauder]

Thats most likely is the problem. The cars get great mileage for thier size on the highway, but in town not so much.
^^^^ I agree. The right foot and low tire pressures will have a huge effect on MPGs. I can drive mine down to 14-15 MPG when I am feeling frisky. :D Just chalk up the cost to "entertainment". ;)

[Stranger in the Black Sedan]

Just chalk up the cost to "entertainment". ;)
Ha ha entertainment without the burn afterwards when you pee. Wait a minute....

[Mote]

If you want better gas mileage get a Prius..............

I just want to make sure my car is running correctly. I certainly don't expect to get 30MPG. Sounds like I'm in range for mostly city driving, albeit the low end of the range.

[Stranger in the Black Sedan]

How old are you though? There is an inverse correlation w/ age and gas mileage on the panther chassis.

[Mote]

How old are you though? There is an inverse correlation w/ age and gas mileage on the panther chassis.

Fifty one. Are you saying I should be getting 18MPG? That's what *I* thought! I feel I drive mellow, given the temptations :burnout:

[Stranger in the Black Sedan]

LOL I'm just kidding, kinda.

[fastblackmerc]

My wife can get better mileage than me when she drives the Marauder. When I drive it the gas pedal is like an ON / OFF switch.... either it's ON or it's OFF!

[Breadfan]

I'm getting 15-16mpg with a Trilogy commuting in traffic. I don't get much cruising time, just spurts here and there. I can see in city traffic not doing much better even stock. You gotta get it going, it will take the same amount of gas to move a big beast each time you have too.

[DOOM]

I wish I could get 16mpg out of mine! :D :burnout:

:drive:

[ctrlraven]

I get 18-20 and that's driving medium aggressive 80% highway 20% city but morning traffic is always stop and go. I've gotten a best of 24-25mpg on some long trips cursing no less than 75 mph with triple digit romps here and there. lol

As of right now it's getting ZERO mpg since it's just parked and fully off DD duty!

[GordonB]

Mote,
When did you last check tire pressures? If you are experiencing 20 degree days, you may need to add air to compensate for drop in presssure. Be sure you are running 35 lbs cold, F & R. FWIW.
GordonB

[Mote]

Mote,
When did you last check tire pressures? If you are experiencing 20 degree days, you may need to add air to compensate for drop in presssure. Be sure you are running 35 lbs cold, F & R. FWIW.
GordonB

That's not it - I was running 35 front and 38 rear. It didn't get cold into the 20s until last night, and as of this morning I have snow tires. But I was getting crappy mileage when it was in the 50s/60s.

[DOOM]

60pound injectors don't help any.

[bosscj72]

I have been real lucky with my Marauder. It is basically stock and I got 24.2 MPG driving home from Nashville to Hotlanta. Then have averaged 20-21 over the last 3 drives with the car using all 302 HP! It is a great car for me. When my trailer goes on all will be over (4,000 pounds loaded and a Brick in the Wind outline at 24 feet!).

Dave

[Thunderace]

the what's your mpg thread is going on now - and i just finished a tank and i am getting just barely 16mpg - my car is stock (yeah i know, i need a tune!) and i drive 70% city 30% highway. I drive medium aggressive. Seems like i am at least a couple mpg from average. The car (seems to) runs great, is way clean - what could i look for?? Should i be concerned? I guess i am...

we never drove our marauder in the winter, but cold/cooler weather will pull your mpg's down,warm up's etc.,city driving pull's it down more,i think a stock airbox set up works better in cold/winter time's,dont get me wrong cai are great when it's warmer (imo). Dont worry it will get better when it warm's up. We never did alot of in town driving but avg.20 mpg with it going up to 22-24 on long haul's. You sure you want to drive that thing in a minnesota winter? I could'nt do it.

[Thunderace]

that's not it - i was running 35 front and 38 rear. It didn't get cold into the 20s until last night, and as of this morning i have snow tires. But i was getting crappy mileage when it was in the 50s/60s.


"medium aggressive" driving pull's it down at least 2-3 mpg's! Imo.

[fastblackmerc]

Interesting article.

Three words: "time to temperature." In cold weather, our vehicles take a much longer period of time to reach full operating temperature. And they take this extra time each and every time we start them up, even if they have not fully cooled down.

Modern engine-management systems are very efficient at optimizing the fuel/air ratio entering the engine. The oxygen sensor monitors the percentage of oxygen in the exhaust, compares this with the percentage of oxygen in the atmosphere, and generates a low-voltage signal that communicates this ratio to the computer. The computer then adjusts the pulse-width of the fuel injectors -- the precise period of time each injector is open on each injection cycle --to fine-tune the amount of fuel reaching each cylinder.

The system makes this very fine adjustment dozens of times each second, working very hard to reach the optimum air/fuel ratio for any given situation, and at steady-state cruise speed seeks to approach the perfect ratio of 14.7 to 1, called the stoichometric ratio. The system is running in a "closed loop" when it is relying upon the oxygen-sensor signal to fine-tune engine operation.

But the engine-management system can seek this optimum air/fuel ratio only when the engine is up to full temperature. In fact, the computer does not look for a signal from the oxygen sensor until it approaches full temperature. During the warm-up cycle -- which takes considerably longer in cold weather -- the computer operates on a warm-up program based on coolant temperature, mass airflow or MAP sensor input of air volume and temperature, throttle position and engine rpm. This is called "open loop" operation, meaning the system is not operating off the feedback from the oxygen sensor.

In open-loop operation during the warm-up period, the engine requires -- and is provided with -- a richer air/fuel ratio to ensure good combustion.

It needs this extra fuel for the simple reason that a percentage of the atomized, then vaporized, fuel delivered to the engine condenses into liquid gasoline on cold internal engine components such as the intake manifold, intake valves, pistons and cylinder. And remember, it's gasoline vapor, not liquid, that burns.

Until those parts warm up, the engine needs more fuel to operate with reasonable drivability. Thus, the colder the weather, the longer it takes for your engine to reach full operating temperature and closed-loop operation, and thus the more fuel the engine uses to deliver the same driving cycle. That's the primary reason your engine consumes more fuel in winter driving.

Another factor in winter mileage is air density, defined as the number of air molecules per cubic foot of air entering the engine. Remember that 14.7-1 air/fuel ratio? That means 14.7 parts of air are mixed with one part of fuel for the perfect air/fuel ratio -- that's a lot of air!

In winter, colder air means denser air -- more molecules per cubic foot. At any specific throttle setting or opening, the same number of cubic feet of air, but containing more air molecules, will enter the engine. The computer will provide more fuel to create the proper air/fuel ratio at that moment. This is a bit more subtle, since "more air/more fuel" produces more power, so you may be able to operate at a slightly lower throttle setting -- sort of rebalancing the equation.

[Breadfan]

Good article. This is why short trip driving, esp. in winter, will yield lower MPG's. When I changed jobs, I went from an 8 mile commute against traffic to a 25 mile commute in traffic. My average MPG's actually went up a bit, even with the traffic, because my car was at operating temp more than during those short trips where, in winter, it would barely be warmed up by the time I pulled into the parking lot.

[JimmyXR7]

Three words: "time to temperature." In cold weather, our vehicles take a much longer period of time to reach full operating temperature. And they take this extra time each and every time we start them up, even if they have not fully cooled down. . . .

Very detailed, good write-up.
Also the winter gas has more of the lighter fuel components such as methane. The winter gas mile reduction is about 5%.
I wait until my vehicles engines warm up before I turn on the heater. Usually right after I get onto the freeway.
In the last 30K miles my MM has delivered 19.2 MPG. 50% freeway. and 25% at 40-45 MPH on Boulevard. Freeway is stop and go in evening.
Jim

[GreekGod]

I get ~14mpg...mostly short trips, in town...my commute is 7 miles. Hiway is ~17, this time of year. I check every tank & I would say yours is quite normal.

[breeze]

i can get 300+ easy in city.

[Kennyrauder]

You are pushing 4200lbs. , what the hell do you want???? A marauder will deliver decent mileage on a steady cruise. My Marauder is modified but I will never complain. I love my Marauder... especially when Mustang Cobras with the stock 5.4 S/C come by & don't want to try to be beat up.I really think with a good launch I could take them. Am I dreaming. 425 RWHP ......4:10 Ford Racing Gears. Lidio Tune