I recently purchased a 2000 7.3L psd excursion limited, I was wondering what kind of mileage I should be getting, I drive on fairly flat ground, and usually do not exceed 70-75 mph, my rear end ratio is 3.73 I think, I have been getting around 14.5mpg lately, it seems that I used to get better mileage a couple of month ago, does the heat have something to do with it? It has been miserable around here lately. Also, I had the high pressure oil pump replaced about a month ago, was leaking a serious amount of oil, happend all of a sudden and I brought it to the dealer right after I noticed, I dont think I ran the system too low on oil, anyway about 3 days after I got it back from the dealer, I noticed a diesel smell inside, I got out and noticed diesel running down the front of the engine, being that I was 120 mile from home I just left it alone, well I havn't noticed a drop of diesel since or the smell, I wonder why it would leak once like that and then just stop, this has been like three weeks or a month ago. and then this morning when I started it it "fired" immediately but surged three times before it went into smooth idle, does this sound like air in the fuel system? I am not real familiar with diesel engines. Is there fuel related components attached to the pump, I know that it controls the injectors but is there actually fuel lines the go to and from it? Any help would be greatlly appreciated, thanks in advance

 

I would say anywhere in the mid 14's for city driving sounds about average. Their are always going to be people who get allot more , and allot less.

The heat would not have anything to do with a loss in MPG , except for the fact if you have the A/C on , that will put more stress on the motor , and possibily a small loss in MPG....

Try a fuel additive such as Power Service Diesel Kleen. It will clean your injectors , and is said to up the cetane rating up to 2 points. I use it every other tankful.....

 

I'm going to agree with JoeBoost on this one. Your fuel injejtors are probably dirty and need cleaning bad. I recently started using Power Service's Diesel Kleen, and already I've noticed a huge difference. After dumping most of the bottle into the tank after I filled up, one thing I noticed is that I got a better start out of it. My X didn't even have to finish too much of the first turn before it started. My acceleration got better and the hard shift into third gear that almost all X owners have to deal with, wasn't as noticeable or obvious. With better acceleration, that naturally means your horsepower and torque levels have gone up, yet another bonus. One thing that really got me was the improved fuel mileage. (my tank was filled to about quater tank a few days ago.) One of the first things I look at when I turn the key to the start position is how much diesel I have. I looked this morning and it was a little above quarter tank. I drove to and from work/school today and the needle didn't budge, very much. I was shocked because usually it will drop below the quarter tank mark and work it's way down after a day of driving to and from work/school. If you can't get your hands on some Stanadyne or you live where it doesn't get very cold during the winter, I recommend Power Service's Diesel Kleen everytime you fill up. You can get it at Wal-Mart for about $3 to $5, it's worth every penny.