20.1 MPG (1682 miles / 83.8 gallons US)

[MR.T]

Just home from some back-country camping and exploring in Death Valley. Great trip, no problems. 1682 paved highway miles / 83.8 gallons = 20.07 MPG.

There's been a few individual tanks that calculated a hair better, but this is a new personal long trip record. There's no special mods -- Just good injectors/IP and proper timing, top quality tires, synthetic lubes everywhere, and driving slower then I want to.

The latter part, driving slower, is a big factor. Most of it was 2-lane highways, a different route then previous trips thanks to a new GPS and Google maps. Average cruising speed was about 58 MPH. There was a few short stints at 70+. But for me, cruising at 70 is worth about 16 mpg (best case, on flat ground).

BTW - the price for a gallon of diesel at Furnace Creek in Death Valley was $5.88. But, not that bad when you consider the remote location.

 

[dieselgiant]

Yep, speed is a big factor in mileage I got 22.5mpg on a 190 mile trip going 60mph the whole way. Glad the trip went smoothly.

 

[ocnorb]

Wow! That is awesome.

Amazing what slowing down can do. Did you find the pace more relaxing?

 

[Brianedwardss]

So THAT's where you've been escaping from the 7 months of rain we've had up here. Sounds like a nice trip, glad the truck did well.

 

[TWeatherford]

I'm sure speed is the biggest factor, but if you had the topper on thats in your signature pic I'd say it would do some to eliminate some drag.

 

[flareside_thun]

Awesome news.......now where's the pics????

 

[MR.T]

Wow! That is awesome. Amazing what slowing down can do. Did you find the pace more relaxing?

Yes, both the wife and I found it more relaxing. Work, and life in general, is too much rush-rush-hurry. Saving almost a $100 in fuel felt pretty good too.

So THAT's where you've been escaping from the 7 months of rain we've had up here. Sounds like a nice trip, glad the truck did well.

I wish! -- Actually just a week. It was a nice trip -- Part of the fun is seeing our machines, that we take such enthusiastic care of, perform well.

I'm sure speed is the biggest factor, but if you had the topper on thats in your signature pic I'd say it would do some to eliminate some drag.

Yes, that top is pretty much always on. I think it might help a bit too.

Awesome news.......now where's the pics????

I'll post some after we get things organized and cleaned up.

 

[IDIDieselJohn]

Well your gonna laugh at me when I tell you my 2wd '89 F150 300 straight 6cyl gets 14mpg on the highway doing 55mph.....

C6 with 3.55 don't help but STILL! And according to EPA ratings, that's right on the money for that truck! Ridiculous!

I miss my Diesels!

 

[franklin2]

You can do some research on the subject, this is coming from my memory banks, but wind resistance is not a linear curve relative to speed. Around 60mph there is a "wall" and after that the fuel requirement to go above that is much greater. The government knew about this, that's why the speed limit was dropped to 55mph years ago to save fuel.

I believe I remember there is another "wall" around 200 mph. In the old days of drag racing they thought the horsepower requirement to pass this 200mph "wall" theoretically could never be reached, but we all know they did it a long time ago.

 

[IDIDieselJohn]

^^^

Very interesting, i've heard of that to along time ago to, didn't remember!


I do plan this year to cruise at 55 in my camper, usually it was always 60. And I got ~12mpg cruising at 60.

 

[MR.T]

Wind resistance varies with the cube of the speed -- Doubling the air speed requires 8 times the power to overcome the air speed drag. But since faster means going further in a given amount or time, the energy consumption from air drag for a given distance varies roughly as the square of the speed (twice as fast takes 4 times fuel). There's other sources of friction and efficiency factors, but the exponential increase in drag from increasing air speed is huge -- especially with the aerodynamics of a brick with rounded corners.

Here's an article http://en.wikipedia.org/wiki/Fuel_economy_in_automobiles .

 

[MidnightBlade]

I think that they proved "Orange Peel" on your paint helps with fuel mileage too. Kind of acts like a golf ball flying verses a smooth object. The golf ball creates little air pockets around the dimples whereas the smooth ball as more drag.

 

[towtruckdave]

Well, thats a new one!

What if I glue fur all over my truck?

I think that they proved "Orange Peel" on your paint helps with fuel mileage too. Kind of acts like a golf ball flying verses a smooth object. The golf ball creates little air pockets around the dimples whereas the smooth ball as more drag.

 

[MidnightBlade]

Well, thats a new one!

What if I glue fur all over my truck?

I'd say you now have a Shaggy Wagon