Fuel milage drop????

[smartineau]

I just got back from a 700 mile almost exclusive freeway trip and got 15. 5mpg,basically running empty. The truck has 9,300 miles on it now and 3. 73 gears, on the way over to Spokane I drove almost 75mph the entire way, on the way back 70 mph.



This is my first long constant freeway trip, I did a mostly highway trip with 2,000 pounds in the bed awhile back and got 17. 9. My everyday all around mpg is/was 16. 5 to 17. 0 with lots of city driving. Just prior to this trip I had a tank that with mostly freeway (350 miles) and some city (150 miles) I got 18. 0 mpg.



When I drive local freeways and traffic allows I drive 70mph.



The week prior to this trip I changed the fuel filter (then I got the 18mpg tank).



The day before the trip I went to install the Scotty Ram 3 (I did not like the way it rests on the wires and is not bolted or screwed in place, I will call Rod to ensure I am doing things right), I put he stock filter back on. The filter did not appear to be very dirty and still everything appears to be seated properly and seated properly.



So why the drop in MPG?



TIA



Steve

 

[preleeguy]

MPG Drop

I have noticed that there are certain places I fill up I have seen a milage drop. I think it is the quality of the fuel. Next tankI go back to my regular fuel stop and the milage goes back up. You may truy to see if this is your problem or find a new place to refuel. Just a thought. Best MPG improver I know of comes connected to your right leg.

 

[Prairie Dog]

I've noticed my mileage drops alot if I go from 65 to 70 or 75.

65= 19+, 70 - 75=15+.

 

[RichMorris]

fuel milage

I am somewhat disappointed with the fuel milage I am getting out of this HO 48RE WITH 4:10 gears. My 96 and '01 HO bboth had the 4:10 and I averaged 17. 5 to 18. 5 mixed driving. Towing a car trailer (appx 5K) yielded 14 mpg. Towing 13K fifth wheel 4300 mi mixed mountains and flat land I averaged 9. 85mpg (21K GVW). I realize the '03 HO is heavier, has six wheels on the ground and has higher HP (more fuel) but I did not expect a 2-3 mpg drop. One short word of caution. Placing an air filter back in the airbox may not get you the seal that you would expect. These engins will pull air around the seal and dump dirt into your engine. I did this once and was surprised at the dirt trail down the side of the filter. I always use a new filter whenever the airbox is opened. Rich

 

[Vaughn MacKenzie]

Very good point Rich about reinstalling the air filter. I have some silicone paste and I run a thin layer around the perimeter of the filter for a good re-seal.



smartineau I wouldn't worry about one "bad" tank, a trend would be a concern. It could be the time before your last fillup you didn't top it off very well and that would make your mileage appear worse.



With my 2wd running 75-80 doesn't seem to kill mileage that bad. I usually get right around 20 running in the high 70s, 21 at low 70s. Best tank was 23 running mid-high 60s.



Vaughn

 

[smartineau]

Thanks for the replies, as long as I am just driving too fast that is acceptable. I was worried that something was wrong two tanks of fuel and both lowered MPG.



After thinking about this for a few days, my rural country driving is usually around 50-55 mph and can generally stay in 6th gear. So this probably helps my mileage.



Steve

 

[91W350]

We just made a 3500 mile vacation trip, all across Nebraska, Kansas, and Missouri, no big hurry to get anyplace. We stopped to visit many historical spots. The best mileage was 19. 9, the worst 19. 1. The Edge EZ has the computer pretty well messed up. The monitor read as high as 26 mpg, but when I fueled, it always came in just above 19. Most miles were logged at 65 to 68. Three boys, two adults and a load of camping gear. I made a run to Topeka the other day at 73 and back to the good old 16. 5 mileage. Speed really kills it, of course it displaces a lot of air and does tip the scales heavy. We are way ahead of my buddy with the standard cab Hemi getting 12!