Well, I just purchased a 2005 Eddie Bauer Ford Expedition, trading in my 2000. Although the specs say the 2005 motor produces more power, it is markedly slower!! Is it a bad motor? Taller rear end gear? Changed transmission shift points for better milage?? Any ideas? :smack:
That should be "mileage".The new style weights about 500 pounds more than the old 2000 model. Your new one could also be geared differently.
Optimum performance is sometimes not obtained until after the engine has run in, usually about 2500 miles or so. An improvement in acceleration of 3-5% is completely normal in that respect. There is also the factor of manufacturing variation to consider; your old truck could have just had an exceptionally good motor while the new one is a little below par. The power curve of the new motor (assuming you got the new 24 valve 5.4 liter V8) is probably substantially different. The factors you mentioned are also possible culprits.
All that being said, your seat-of-the-pants impression could be in opposition to fact. The old truck may have just felt faster. Since you no longer have the old truck, a true comparision is not possible. Didn’t you notice the difference during your test drive? You did drive the new truck before signing the contract, didn’t you?
To expand on sewalk’s “seat of the pants experience” discussion, your impression of your vehicle’s power is most likely formed by your experience of the vehicle’s pushing you back in the seat in first or second gear at high throttle settings.
Unless you race it on the track every day, horsepower will tend to matter to you less than torque.
Why don’t you take the old Expedition’s weight in lbs and divide it by the engine’s output in ft-lb of torque?
Compare that to your results for the new one.
You may want to add your weight to both vehicle weights before doing the comparison.
Oh yeah. Some quick research shows:
The 2005 makes 301 HP SAE @ 5,000 rpm; 365 ft lb @ 3,750 rpm with a 5.4 Liter V8.
It is 7100 lbs fully burdened or 5,352 lbs empty.
The base model 2000 makes 240 HP @ 4,750 rpm ; 293 ft lb @ 3,500 rpm with a 4.6 Liter V8. I believe a 5.4 Liter V8 was optional.
It was 7000 lbs loaded or 4916 lbs empty.
2005 with 5.4 Liter:
-Loaded, 19.4 Ft-lb per lb
-Empty, 14.6 Ft-lb per lb
2000 with 4.6 Liter
-Loaded, 23.9 Ft-lb per lb
-Empty, 16.8 Ft-lb per lb
Now, let’s presume that your old one had the 5.4 Liter. You can correct me if I’m wrong, but since you have a new Eddie Bauer, there’s a good chance you sprung for most of the worthwhile options on the old vehicle.
2000 with 5.4 Liter
-Loaded, 19.2 Ft-lb Per lb
-Empty, 13.5 Ft-lb Per lb
Well, to be honest, that’s probably not the best explanation. After all, if you ordered the 2000 with the 5.4 Liter, that probably added at least 100 lbs.
Did the old one have a towing package? That might have gotten you a lower first gear, which results in more kick in the keister when you punch the gas.
Thank you for your input! Yes, the 2000 was a 5.4 Liter motor WITH TOWING PACKAGE. I did not buy the towing package this time because I tow only light trailers. I took the truck back to the dealer who drove it and says it is O.K. Also, the computer says the engine is functioning normally. I got 3 possible explanations from the dealer:
- The towing package comes with a shorter rear end, making starting acceleration considersbly better in the old truck.
- The “drive by wire” throttle control seems to be a problem with delaying response.
- The transmission shift points have been changed for better fuel economy. And, as you point out, the 2005 is 400 pounds heavier. Guess I will just have to get used to it. Thanks for your help.