What's up with the MPG on my 98 XLT?

[Hokie]

Originally posted by jagarundi
I guess I'll just have to get used to high weekly gas bills until I get a little hoopty to go back and fourth.

Have you ever done the simple calculation to find out what your mileage is? (Distance traveled/gas used = MPG)

 

[BradE.]

Check your air filter, spark plugs, plug wires. It might help you squeeze a few more MPG's out of it.

The main problem though sounds like your driving style. Keep the speed under 70 on the highway, and your MPG's should improve.

 

[stubborn1]

V6 isn't much better

I have a 98 with the OHV V6, and my mileage averages right around 17mpg summer and 15mpg winter. On a pure highway trip I can hit the 20mpg mark. In stop and go driving, I'm down around 15mpg.

I would rather have the V8 and loose 1-2 mpg.

 

[sean4385]

from what i hear the most fuel efficient speed is 65mph, anything above or below that your mpg will decrease.

of course this means 65mph with an acceleration rate of zero. in other words you are going at a steady 65 and not speeding up or slowing down.


Another thing to consider, for those who dont already know, the level of your RPMs (how high the rmps are and how long they are at that level) determines how much gas is being burned up, nothing else. Thats why accelerating alot, and/or accelerating too rapidly, decreases your mpg.
So when i said 65mph is the most fuel efficient speed, that is because your RPMs are the lowest for the amount of distance you are travelling over the shortest period of time.

Later,
Sean

 

[Alec]

Yes, the RPM thing is kinda true.

But trucks with different gear ratios have different RPMs at 65.

Also, wind resistance increases exponentially with speed, so speed does have much to do with fuel efficiency.

The best RPM for mileage with the X is around 2600, somewhat less for the 5.0, and somewhat more for the SOHC.

 

[sunbum]

I'd totally be checking your filters... fuel, air... if your engine is wheezing and coughing to get air, it's going to work hard to give you the response to the accelerator and suck gas.
How is the path to work? I have a hilly path and a not so hilly path... perhaps you can take an alt-route and see if that has an effect.

Had a tune-up lately? Might be another consideration...
don't scrap it until you check some of that out.

 

[Rubberhead]

I have a 2WD 2003 X with the 4.6L V8.

I'm getting 16 in stop and go traffic and 20-21 on the interstate.

 

[sapogmxr]

Rubberhead thanks for rubbing it in.

 

[jagarundi]

Originally posted by sunbum
I'd totally be checking your filters... fuel, air... if your engine is wheezing and coughing to get air, it's going to work hard to give you the response to the accelerator and suck gas.
How is the path to work? I have a hilly path and a not so hilly path... perhaps you can take an alt-route and see if that has an effect.

Had a tune-up lately? Might be another consideration...
don't scrap it until you check some of that out.

The path to work is through city streets for a ways and then highways and expressways to the office. I just changed the air filter last weekend and the plugs seem okay.

 

[Billy177]

time for new o2 sensors

 

[PAExplorer]

YOU HAVE TO GET NEW SHOCKS!! This has nothing to do with your MPG, but driving as fast as you do on the highway, you can eaisily loose control when you hit a bump. I've got a 98 sports and when I was on the stock shocks, I almost crashed two or three times. It's really bad when your going over sixty and you hit a bump on a turn. Even a small repair in the road during a turn can throw you into the other lane. Get new shocks!!!, it's worth it and you'll feel an immediate difference. Also, if you insist on driving that fast, you may want to get new beefier sway bars to increase the stabilization. Hope that helps.
-E

 

[aldive]

Originally posted by Alec
The best RPM for mileage with the X is around 2600, somewhat less for the 5.0, and somewhat more for the SOHC.

Not in my SOHC.

 

[2001ExpSport]

How much do you full up? The amount of fuel you put in is close to what you used. Use that to determine your mpg.

If you only get 200 miles to a tank you're just about 10mpg.

 

[2001ExpSport]

Originally posted by jagarundi
Mind you, this is city driving in the beginning of the morning, followed by highway driving at 80 - 90mph later on. It appears that everyone here thinks that the mpg is about normal. Should I just suck it up and face the reality or try looking for a 6 cylinder suv? If so, would the 6 make a difference at the gas pump?

Commuting to LI....get a 4 cyl. Use the 5.0 for evening and weekend outings.

 

[jagarundi]

Originally posted by 2001ExpSport
How much do you full up? The amount of fuel you put in is close to what you used. Use that to determine your mpg.

If you only get 200 miles to a tank you're just about 10mpg.

I don't let it get to 'E' I fill it up when it's about a little less than a quarter tank. I'll then drive to work and on the way back home, a quarter tank burns. The next day, I'll drive to work and on the way home, another quarter tank burns.

 

[Hokie]

Originally posted by Hokie
Have you ever done the simple calculation to find out what your mileage is? (Distance traveled/gas used = MPG)

Quarter tank is relative. Next time you fill up, reset your trip odometer. When you fill up again, record the miles traveled and the gallons used. By asking why can't I go farther than some fraction of the tank we can't tell you much. You might just find that your MPG's are consistent with others.

 

[2001ExpSport]

Originally posted by jagarundi
I don't let it get to 'E' I fill it up when it's about a little less than a quarter tank. I'll then drive to work and on the way back home, a quarter tank burns. The next day, I'll drive to work and on the way home, another quarter tank burns.

Well you stated that you travel 50 miles each way. If that's the case you are getting just about 400 miles to a tank on the given that to and from work a 1/4 tank is used.

Looks like your getting a normal MPG

Like Hokie said, reset your trip odometer and use that mileage to determine mpg when you fill up. You need to take the average of three fill-ups to get a good number.

 

[01 Daily Driver]

Originally posted by 2001ExpSport
Like Hokie said, reset your trip odometer and use that mileage to determine mpg when you fill up. You need to take the average of three fill-ups to get a good number.

That's really the only way to know your actual MPG. Trying to guesstimate from the gauge isn't very reliable.

I'm averaging 16.8 city driving in my 01 4.0 SOHC Sport.

My old 4.0 Cherokee Sport averaged around 18 or so.

My 5.7 litre Chevy does better than either at 20-21 in town with a best of 30.4 MPG on the road.

 

[fatcougar]

I agree with Billy177. If your O2 sensor(s) are bad , the computer defaults to a preset value for fuel mixture which errs on the side of being rich. This happened to my X and I noticed an increase in milage once I had replaced them. You would need a scanner of have someone scan it to be sure though. Jsut my 2 cents.
( And here my wife says I don't have any).....

 

[jagarundi]

I changed my front shocks over the weekend. It rides a little better. I finally figured out my gas mileage. My gas tank is twenty gallons. When I fill up my tank and drive to work, I'm burning a quarter tank. That equals a one way, 50 mile trek. Coming home, I'm burning another quarter tank. That also equals a 50 mile trek. Bottom line. I'm only getting 10 DAMN MILES PER GALLON ON THIS GAS GUZZLING PIECE OF &*$#%! Tell me that something is wrong with this picture! What should I check for now, before I leave this in the dealerships parking lot next week?