That is exactly how my '93 f150 is. So I guess everyone learned a lesson here......me because I learned why my '04 won't hold it's speed, and everyone else who said it's impossible for any vehicle to hold it's speed now sees that not only my '93 will but also that other peoples' vehicles are capable of it.

 

A friend of mine has a 2001 Dakota V6 auto. It does not slow down on our local grade. She has to ride the brakes going down the pass just like everyone else. She also gets a lot worse mileage than my much bigger and more comfortable F-150. She commutes the Cajon 6 days a week, and gets 16-16.5 regularly. Going to and from the same location I get 20.9 to 22.5. We drive the same speed, and run together. We have made the run in tandem about twenty - thirty times this year (business), and the gas mileage is very consistent on every trip.
Her next truck is going to be an F-150.
Chris

 

that is impressive gas milage. you must be getting like 30 plus mpg coasting down the grade to average 22 mpg on a trip that includes comeing back up the grade. you should figure your mpg's just going down one time. I bet it is high.

 

Actually I have a Scangauge so I track every part.

It's 23-24.5 going down, and a decent 19.9-20.5 coming up, on the whole 140 mile trip.

The pass is only 15 miles of 70 miles each way. On the actual pull on the steepest four-five miles up to the summit it gets 50-80 going down (no need for throttle) and 12-14 coming up.

That's a reg cab, aluminum tonneau, 3.55 gears, 18 inch tires, Magnaflow catback, 4.6 Brute force intake, Diablo premium tune. So I am set up for mileage.


Chris

 

so I see you are set up for gas milage. but I would not trust any electronic device that tells you the gas milage you are getting. how can it tell. dose it measure how fast your gas is going down in the tank. that couldn't be acurate. maybe it is just me not knowing how these things work. maybe it is just based on how open your throttle is related to how fast you are going. I don't know how it works but every senerio I can think of dosn't seem vary acurate. it would be interesting to know how it works so I could deside if I trust its acuracy.

 

Well, I've had the electronic mile-gauges on my last 6 or so road cars, Cadillacs and G.Cherokees. Worst was off 2 mpg around town, 1 mpg on the highway. The best (my wife's touring coupe) has never been off even 1 mpg on a fill up. Usually within 1 or 2 tenths.

I track mileage on every fill up, on every car/truck we own. I always calculate it manually. The Scangauge on my F-150 is about average, 1 mpg off around town, .5 off on the freeway. So I always adjust for that when I post.

The OBD II system is pretty darn accurate.

Even my little Tracker, checked with the Scangauge vs. actual calculation is within 1 mpg.
Interestingly enough, the Tracker is the only vehicle I have ever tested that always got better gas mileage than the OBD II reported. Usually about 3 or 4 tenths, but I have never tested it with the Scangauge on the open road. Who takes a two door Tracker on the open road? Only time it leaves the area is on the back of the motorhome.

So anyway, the electronics are pretty good nowadays.
Chris