VERY POOR MPG

Advertise with us
Shop deals on ebay
shop deals on amazon
Ford SportTrac Forum

Help Support Ford SportTrac Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
C

Chris Huffmire

Active Member
Joined
Nov 4, 2008
Messages
106
Reaction score
0
Location
Ft. Eustis, VA
I Have a new 09 STA. about 45 days old with about 4000 miles on it. So the break in period is over.

This thing is i am now seeing a decrease in MPG. The computer is saying its at about 12.2 MPG. I went from about 17 MPG to 12. WTF!! I am not mashing on the gas or doing quick starts, (except for the times its needed) but the MPG should not be that low. andyone got any ideas, or should i take it into the shop?
 
Chris,



Is that city, highway, or a combination of the two? Bill's right in that the on board computer isn't always going to be accurate.
 
I have 80k on my 02 and my overall MPG (highway, city, general) has always been about 15.5-16.5 and during the winter that drops to about 12. My wife see's the same same impact with her 08 Honda Pilot. In my case, I do like to warm up the ST in the AM, so I am sure that adds to the lower overall mpg.
 
A lot of factors can cause poor fuel milage, including a faulty computer. Also remember that while you are past the break-in period, you engine is not really completely loosened up until you get about 10K miles on it. I had two Sport Tracs and noticed that when I passed the 10K mile mark, both vehicles suddenly had a very noticable jump in gas mileage.



You might also want to check your tire pressure and inflate them a little more than the sticker says. Must people find that 35 PSI front and rear gives better mileage and an acceptable ride that is not too harsh. If you have not switched to a 100% synthetic oil, do so ASAP. That is usually good for about 1-2 MPG improvement.



But the best advise is to not rely on the onboard computer. Measure your miles and get an accurate pump reading to be sure of your gas mileage. And don't rely on just one tank. Just stopping a few extra traffic lights can put a big ding in your average MPG for a single tank. You really need at least 4-5 tanks full before you can average out all the unusual peaks and valleys that occur in normal driving.



...Rich
 
That sounds about right for winter combined city/highway driving actually.



The STA doesn't like city driving. With those 3:55s the V8 and the 6 speed it's all ment for the highway imo.
 
Alright. well i guess i wait for about 10k and I guess i wont rely on the computer to give me my MPG. I ill have to do it old school. Thanks for the heads-up everyone:cool:
 
I did an experiment with the built in MPG computer today. I knew I would be idling for a long time, so I reset the computer. It continued to read 0 MPG as long as I was idling. After I started driving, it took forever for the average MPG to get above single digits. I have always suspected that computer weighs idling into the average MPG inaccurately, and I think my experiment proved it. There is no way I even used 1/2 gallon of gas idling, but the computer averaged it like I'd burned 10 gallonns at 0 MPG. Just another reason to use the old fashioned method and ignore the computer. Its pretty accurate for highway driving, but not for stop-and-go.
 
As stated above watch for additives but also I noticed that getting fuel from a different station made a difference. I was filling up at a local Hess station right by my house. The STA kept averaging about 14 or so and I figured what the hec it's a V8 mostly city. By chance I stopped at the Chevron by work and the fuel mileage jumped a full 1 mpg during that tank so I kept using that station for the next 4-5 tanks, it kept about 15.1 mpg. I went back to the Hess just for kicks and over the next tank full the average dropped back to almost 14 with normal driving, I don't go to the Hess anymore. Could be additives, could be process or it could be a coincidence but I don't go there for fuel anymore.
 
I get 17 mpg in town and a bad trip nets about 24 on the road.

I have my injectors cleaned once a year at my Ford dealer as part of the maintenance I have done.

I have a 2002 V-6 2wd my wife uses it as a daily driver and I feel better

if she drives it as it is a lot better to be a vehicle that big vs some of the

other cars out there.

My wife does not hot dog it.It has 54K on it now.
 
SKRX is correct about how the onboard computers calculate the MPG. The all calculate the mileage you are getting when stopped at a traffic light or just idleing...which of course is zero, but it all depends upon what kind of read out your are getting.



My Mercedes has 2 readings. One MPG reading is from the time I reset the computer which I have never done so I am averaging 24.3 MPG for the 1nearly 5K+ miles I have owned the car.



The second setting is reset when the vehicle is started and measures the average MPG for this current trip. It maintains the same trip details even when the engine is shut off as long as it is restarted within 4 hours. That way you can drive, stop for gas or eat and not loose your average MPG. I have gotten as good as 31.8 MPG over an 800+ mile trip. When I start out it may show 15 MPG but the more I drive at a steady speed the quicker the MPG improves.



If I pull away from a light quickly, I can see the MPG drop by 0.1 MPG about every 20 feet as a move down the road. If I accelerate gradually, it might only drop 0.1 MPG every 200-300 feet until I reach cruising speed and then the MPG starts to climb back up. Of course the longer I maintain the same speed, the less impact a quick burst of acceleration has on the over all average MPG. By watching these MPG readings you can really see what is eating up your gas, and what kind of driving saves you milage. The biggest waster of gas are hard acceleration, of course, any acceleration will use more gas even if it is gentle. It just takes more gas to get the vehicle moving than keeping it crusing at the same speed. The heavier the vehicle the more gas it takes to get it moving.



The third kind of MPG reading is an instantaneous reading which calculates the amount of gas you are using based on the speed you are going and gives you and instantaneous reading for that moment in time. That can make huge swings in a very short amount of time. It's an interesting reading to watch, but does not really indicate your average MPG. Most car computers do not have the instantaneous MPG feature.



...Rich











 
What Gavin mentioned is really important. Make sure you're not filling up with fuels that contain ethanol. It's a huge difference in mileage.
Click to expand...



Can't help it around here. The governor mandated that all fuel has to have a minumum of 10% ethanol in it. This is to help the Big Corn lobby and all the ethanol plant investors.



My mileage took a noticable dump when we had to convert to 10% ethanol.
 
Last edited by a moderator:
Can't help it around here. The governor mandated that all fuel has to have a minumum of 10% ethanol in it. This is to help the Big Corn lobby and all the ethanol plant investors
Click to expand...



Same in Florida...
 
Yes, Gavin is correct. the States and some cities mandate the fuel blends that are permitted in their service stations, and the winter blends are bad about adding too much acohol into their gas. Alcohol will mix with water and so it will absorbe any moisture in the gas and prevent fuel line freeze ups, but mileage is terrible. However in the summer time, you will find some gas stations that provide gas with less alcohol blended in, and that gives you better mileage. Generally speaking, the cheaper gas will have more alcohol blended into the gas than the higher priced gas, but don't use price as a factor. Each gasoline company will have a specific blend of gas for your state or area, and generall the bign names will have less alcohol in their gas.



That's also why some people will claim they get better mileage on premium gas than regular. Premium gas often contains less or no alcohol than the regular grade gas, so you will get slightly better mileage. The question is, does the extra cost of premium fuel offset the mileage gain?



...Rich
 

Latest posts

Top