Why is my MPG soo bad?

[Lesliea]

Hi, I'm a newbie. I recently purchased a 95 explorer limited and I love it. It's in great shape, totally tuned-up and my mechanic says it's sound. It does need a wheel alignment and that will be done in a few weeks. It has the 2 wheel, AWD and 4 wh. drive gears but I'm mainly in 2 wheel. Meanwhile, something strange has happened. When I bought it, it got 10.4 miles to the gallon. After the tune-up it is getting 8.9 miles to the gallon and seeming to be dropping. In Canada we are Kilometers and litres and my odometer is in Klms. so I'm wondering if my math conversion is incorrect. Otherwise I don't know what is happening. What are the other possibilities? This is city driving and I don't idle and it has been cold since I bought the vehicle.
If this is the way Ford is designed, is there any modifications that can be done to improve this consumption. Ford Escort advertizes 35 mpg (4 cyl?) but we shoul all be able to get at least 1/2 that with a 6 cyl..
Any info you can give me will be welcome. Thanks.
Lesliea

 

[EB04FFV]

i just did a weekend trip.
75% highway miles
I got 345 miles before the "check gage" light came on.

thats about 17-18 mpg

Its an 04 4.6 4x4
I didnt use cruise
My tires are filled with nitrogen

I'm interested in the NITROGEN filled tires? Is there a difference, handling,fuel, leakage, prevention of rim rust, keeps air longer?
Pls let us know.

 

[E.B. Cornburner]

I'm interested in the NITROGEN filled tires? Is there a difference, handling,fuel, leakage, prevention of rim rust, keeps air longer?
Pls let us know.

Just another gimmick is all. Some guys at the racetrack use nitrogen in their tires, but that's mainly because they don't have any air compressor. They just get a cylinder of nitrogen filled and keep it on the trailer. They claim it gives more consistent pressures as the night air cools the tires off, and they don't gain PSI when they heat up on the track.
We've never had a problem with just plain air. (and we've beaten all the cars that do use nitrogen!)

I had a guy try selling us a nitrogen filling machine at the dealership here, and I told him no...And gave him a humorous chemistry lesson in the process. I just said we're happy using the 78% blend we're using right now. You should have seen the puzzled look on his face!

 

[aldive]

Nitrogen filled tires is definitely not a gimmick. There is hard science behind the concept.

NASCAR racers ALL use N2 filled tires.

I have plans to do some extensive mileage testing with N@ filled tires this Spring/Summer.

 

[Curtis]

I'm interested in the NITROGEN filled tires? Is there a difference, handling,fuel, leakage, prevention of rim rust, keeps air longer?
Pls let us know.

There was nitrogen in my tires when I bought the Explorer. You can tell by the green valve caps. My interest was peaked when I got the explorer home so I did a little research on it. Here is what I found.

Most tires are filled with compressed air, which when dry consists of about 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases by volume. (just like E.B. Cornburner mentioned). When there is moisture in the air (humidity) thats what allows the fluctuations in tire pressure.

Using nitrogen mainly does two things: it eliminates moisture, and it replaces skinny oxygen molecules with fat nitrogen molecules, reducing the rate at which compressed gas diffuses through porous tire walls. Thats the theory anyway. The commonly quoted figure is that tires inflated to 32 psi get 3 percent better mileage than at 24 psi. (I would think this is the same for regular air too)

More important, nitrogen doesn't support combustion, which is one reason aircraft and the space shuttle use nitrogen in their tires.

The consensus that I found, even from the website where I got this infomration generally agreed that if your tire place does it for free (Cosco I believe but I couldnt confirm it) than go for it. But the Ford Dealer near me wanted $80 to turn my tires around and put the white letters out and fill with nitrogen. I declined. I still have them white letters in.

One thing I did notice is that Ive had the vehicle for almost exactly 1 year.
I checked the air pressure recently and all were the same at normal pressure. My other explorer which has regular air, I had to add as much as 5lbs to all 4 tires.

--> For mpg I think a properly inflated tire with air will get the same mpg as nitrogen.

 

[MoonlightGT]

well i realized something this week. First i went to the ford dealer where my friend works and he said they will hook thee truck up to the diagnostics system and re-boot the pcm with a new program and he said this will help the MPG. Well LAST time i went to my sisters house which is a 2 hour drive on the highway each way, i used 3/4 of a tank. Then i went after the Pcm was reprogrammed and i only used a 1/2 tank. BUT, the MPG indicator on the dashboard computer didnt go up at all from 13.5 -14. so i did the calculation. I filled up before i left, i drove to my sisters and back home which was 1/2 tank, and the other half tank of gas was all city driving. So once is was almost empty i went to the gas station and filled up again and it took 71 litres to fill. So I got 506 kms to 71 litres. Which works out to 16.4 MPG for 50/50 city/hwy. So why is that dash board computer so far off??????

 

[dhays]

When they reflashed the PCM, did they reset everything? My suggestion would be to at the very least, reset the mpg gauge. Better yet, disconnect the battery for a few minutes to reset the ECU.

 

[EB04FFV]

.... re-boot the pcm with a new program and he said this will help the MPG. ..... So I got 506 kms to 71 litres. Which works out to 16.4 MPG for 50/50 city/hwy. So why is that dash board computer so far off??????

Hi Moonlight - you have the 2004 Owner's Guide? on the Message center control
Info/setup/reset, display the calculated avg fuel usage, engage cruise control, drive 5 miles and then press 'reset' that should calculate the new value.
You can get the 04 Owner Guide online, if you cant find it I have one and can email to you.
What is the version of the new program? I'll check that out at my dealer.
But....at 14lts/100 city/hwy thats not bad at all, at this time of the year its almost good.

 

[MadExplorer93]

I don't know about anyone else, but i get around 40mpg out of my 1993 4x4 explorer on the highway and around 25mpg in the city and that is YES on one tank of gas.

I know it is hard to believe, but when you only drive like i drive. The gas in the tank can last many many miles.

 

[EB04FFV]

Just another gimmick is all. ......

I had a guy try selling us a nitrogen filling machine at the dealership here, and I told him no...And gave him a humorous chemistry lesson in the process. I just said we're happy using the 78% blend we're using right now. You should have seen the puzzled look on his face!

I'm not ready to dismiss nitrogen - and like some of the benefits i.e. safety, consistent tire pressure, improved fuel efficiency, extended tire life, reduces rim corrosion (nitrogen is a dry, inert gas) in my area , the temperatures vary big time, day/night and seasonal and cause mostly underinflation, so for a more consistent tire pressure nitrogen seems the way to go.
I understand from my dealer that the equipment cost is about $7-8k and they charge about $ 10 per tire for conversion - which includes lifetime free refills, or if you buy a car fro them they give it to you for free - I admit it's a marketing move, to get you back for the oil changes - why not!

 

[EB04FFV]

There was nitrogen in my tires

One thing I did notice is that Ive had the vehicle for almost exactly 1 year.
I checked the air pressure recently and all were the same at normal pressure. My other explorer which has regular air, I had to add as much as 5lbs to all 4 tires.

--> For mpg I think a properly inflated tire with air will get the same mpg as nitrogen.

Curtis, you made a good point - no air loss in the nitrogen filed tire after ONE year! Case closed.

 

[EB04FFV]

nothing in the trunk. im gonna change the plugs with new motorcraft ones and i got a k&n drop in filter.

whats your total kms so far? Chaning plugs is always good, I installed a K&N filter last year, no effect on the gas milage at all, but seems to respond a bit better, I'msure you noticed a lag when accelerating around corners, and it sounds great.

 

[MadExplorer93]

Ok have the O2 sensors tested as if they are plugged up or not working. Then you will have bad idle, bad gas mileage and this can cause more issues of vehicle running sluggish.

 

[jpserra]

Mythbusters did a check on this and busted it. It is a gimmick, not worth the effort.

JP

 

[aldive]

Mythbusters did a check on this and busted it. It is a gimmick, not worth the effort.

JP

What is "this"?

Thanks ...

 

[jpserra]

Sorry, Nitrogen in the tires.

JP

 

[EB04FFV]

, but when you only drive like i drive. The gas in the tank can last many many miles.

Pls tell us HOW do you drive, I would like to get your milage

 

[shadowless127]

Pls tell us HOW do you drive, I would like to get your milage

lol in Neutral, and down a hill.

I'll NEVER see that gas milleage, More power to whoever can.

 

[crash594]

The only thing nitrogen in the tires does is prevent the constant tire pressure changes due to seasonal temp changes. It does not expan or compress as much as regular air due to the molecules being larger.

 

[MadExplorer93]

Pls tell us HOW do you drive, I would like to get your milage

As less as i can drive that OLD GAS PIGLET... lol

The less i drive it the more MPG i get out of the tank... lol

Weeks on end at times..