onyx

So how do you explain airplanes flying at higher altitudes getting better fuel consumption rates with less air density and colder temperatures? Same principal as vehicles, different application.

budget rapta

I was getting 15 with the old setup and didn't think much of it because the truck had 400 miles when I changed the tires. Figured it needed to break in. Sittin at 2000 and still **** mileage.

BigMcLargeHuge

It's not quite the same principle.

High altitude density is low, so power actually decreases and efficiency improves. Take-off power is higher than high-altitude power in any like-for-like aircraft comparison with a vehicle.

Low altitude density is high, so power improves at the expense of efficiency in cold temps.


There's a difference in it being cold because the thin air can't trap heat (high altitude) and the fact that the sun has one on vacation and isn't heating the dense air (low altitude in winter).

kcmfg

I said that the denser air causes it (which when colder is more dense at sea level), we were not talking about altitudes here. Denser air means more wind drag and more fuel is needed.

Ok I'll admit I did not search on winter fuel blends before posting that, which was stupid of me I get it. I had never heard of that before. So it's a combination of the two. Sorry for misinforming anyone.

I'll still stand by what I said that the denser air from the cold also causes fuel consumption loss. More wind drag, lower tire pressures, longer time for fluids to warm up to optimum temps, more fuel needed, etc.

When the air is cold, it is denser, and hence has more oxygen per unit of volume or capacity. You therefore need more petrol to approximate the ideal ratio of air and fuel.

canon_mutant

Yeah, problem is we had all these arguments last winter and the REAL problem is that these have always cost me, and it seems most folks, 1-2mpg, not 5-6mpg like it does with this motor. Then the following summer you are still down 4-5mpg . . . it doesn't come back.

But mine hopefully will finally be gone Thursday. Driving up to Iowa to have a heart to heart where I bought it. They tentatively offered a cash buy out over the phone. I'll be out $6-8K from what I paid but at this point I'm just glad to be rid of it.

Of course, the falling on its face that can kill you is of greater concern than the mpg loss. But @4.00/gal even the mpg disparity requires a different perspective eventually when Ford like everything else refuses to admit it's even a problem.

Mojoron

The last time I made a comment was last week when I announced that I was finally getting rid of my POS Platinum EB and getting a 250SD. Its not only a SD it is a monster: KR, 4x4, 8foot bed, snow plow prep. I have had it for nearly a week with 689 miles, my average on "B" is 14.4 on "A" it is 19.4. with mostly driving 40 to 60 mph on two lane roads and some city driving. (The B includes all the milage that was put on, 382 is not mine. A is all the milage that I put on the vehicle after I filled the tank and reset the meter). If I still had my EB, my A would be 14.4 since I drive the same routes everyday. So far I am thrilled but I had the same feeling when I first bought my EB, good milage in the beginning but getting worse as the truck got older. For those of you who think the change was wrong, WalMart (Murphy Oil) is having .10 off of fuel using your WalMart card, so diesel is less than 3.78 gallon now, but it is nearly $4.00 at the truck stop. Unleaded regular is 3.54 with a discount of .10. The net effect is that I pay .24 per gallon more for diesel but get 5 mpg better milage so the cost is probably negligible.

I want to thank all those who have persevered through my posts. I will continue to monitor this forum but for right now, good motoring!

Rfjohns2

I've noticed over the last two fill ups that my mileage has improved 1-1.5MPG. Nothing has changed on my part, same driving patterns, etc. I have about 16K on the truck now and my mileage has always been very consistent at between 14-15MPG.

I live in California which has been going through a gas shortage due to a couple of refinery issues. I wonder if it may be that the state is allowing out of state fuel to be sold in the state.

Has anyone heard anything about this?

paddyf150

I have noticed a significant difference from regular farm fuel from co-op and husky 94 premium. The regular bulk co-op farm fuel gets 20-23 miles per us gallon and the 94 premium with ethanol gets 15-17 mpg, I know this sounds crazy but I've been driving like this for almost 40,000 kms and every time I get a tank of farm fuel my mpg's go way up.

XtraLargeTall

It's the ethanol in the 94, it drops mileage alot

JerryC

Took a trip to Dallas from Memphis, a trip that will convince you it is uphill both ways 87 octane both ways. A good bit of TX has 75mph speed limits, that kills MPG. Judging from watching the instant MPG gauge it costs about 1.5 - 2 MPG over 70mph. Only once did I notice it downshift to maintain speed on a hill. I used cruise control as much as possible (to avoid tickets).

To Dallas, with brutal crosswinds and at times headwinds. I checked the tire pressure after I got there and it was 32psi (doh).
Comp says 19.4 mpg
486.6 miles
26.40 gallons
18.43 calculated mpg


From Dallas, crosswinds not as strong and at times would be a tailwind. Tire pressure 34psi (brought them to 35 the night before, they cooled and dropped a psi)
Comp says 21.1 mpg
485.4 miles
24.27 gallons
20 calculated mpg

All stock Fx2 with 3.55's and ~6500 miles at the start of the trip. Me and the wife and a couple hundred pounds of stuff. It has an Undercover SE tonneau.

Interesting that it has a 26 gallon tank, I must have been pretty close to dry when I got to Dallas. It was over a gallon off on the gallons used in the computer for both trips. I did not use the remote start.

I believe that if you took off CC you could gain some MPG, possibly as much as 2 MPG or more. The CC dutifully tries to maintain an exact speed. By using you foot and a willingness to drift a couple of mph in either direction you could save a bunch of gas by coasting more and not accellerating as much to maintain an exact speed.