Road surfaces (tar snakes) and MPG?

[lasitter]

I've been working for years to improve the fuel economy of my 1996 Ford F-150, and under ideal conditions at 55mph, I've managed 30mpg or a little better. But that is under ideal conditions (smooth pavement, calm winds, not raining, etc.)

So I've been thinking of attempting to make the trip from Dallas, TX to Jacksonville Beach, FL, without stopping to refuel. I think it just might be possible, but I'm weighing some different driving conditions and strategies to improve my odds.

So my simple question is for your best guess: How much do tar snakes cost?

Any suspension motion, anything that doesn't make the vehicle go forward, erodes fuel economy.

If you're driving 55, you're going to be in the in the slow lane which generally has a rougher surface than the "passing" lane.

If you could drive in the dark of night, when almost no one was on the road, and therefore not represent a "hazard to navigation" in the left lane, would you gain more in fuel economy or lose it, having to run headlamps and push thru the cooler / heavier / denser night air.

Of course there's also the possibility that you wouldn't need the A/C at night vs day. Lots of factors.

Your thoughts appreciated.

[Gasoline Fumes]

My guess is slower at night without A/C wins.

[lasitter]

Only other factor of concern: If you drive during the day you can get the corridor effect, with heavier traffic.

[redpoint5]

I usually drive offset in my lane if I find myself in the heavily used and worn "slow" lane. If you can make the drive without AC during the day, that is the most efficient time to go. Just running the blower motor alone is likely more power than all of your lights though. If you have to run even the blower, then it's probably better to go at night.

I'd trade vehicles with someone else to make that trip. That way I'm not wasting time going slow, or wasting fuel by driving something inefficient.

[Daschicken]

From Cummin's white paper:

[lasitter]

Originally Posted by redpoint5

I'd trade vehicles with someone else to make that trip. That way I'm not wasting time going slow, or wasting fuel by driving something inefficient.

Thanks for the tips, but the whole purpose of the trip is to show what you can achieve with well maintained, old trucks if you leave the emissions controls in place and drive reasonably. Too many people that drive older trucks are convinced that they'll get better power and economy by ripping out the emissions controls, and nothing could be further from the truth.

[Hersbird]

Originally Posted by lasitter

Thanks for the tips, but the whole purpose of the trip is to show what you can achieve with well maintained, old trucks if you leave the emissions controls in place and drive reasonably. Too many people that drive older trucks are convinced that they'll get better power and economy by ripping out the emissions controls, and nothing could be further from the truth.

Well I don't know if nothing could be further from the truth. I bet a new tune with massive lean burn and no catalytic converter would do much better. NOX would be through the roof but Economy would be up. I'm also very sure that any power gains and losses can be shown with dynamometers and there are things that will increase power especially in the 80's and early 90's the dark ages of emission controls. Increasing power won't help economy but many people do the emission deletes for proven gains in power and don't care about better economy. So again, those things can be pretty close to the truth. You just are more of an economy guy but I guarantee I could make your truck quicker IE more powerful by removing emissions and tuning for power.

[lasitter]

Hersbird: The people that can say FU to the environment and fuel economy both are at the drag strip. EGR / OBDII controls allow for more spark advance, a cooler burn and the very best we can hope for if our environment counts for anything. The moment you start screwing with the air pump and other controls, the system starts throwing codes and goes into degraded modes of operation. Most of us are not in a position to remove the friendly to mother nature stuff and then replace the PCM programming to restore the vehicle to proper function, even forgetting the environment. Of course we could get better fuel economy without emissions controls, but then again, we haven't had 100 octane (generally) at the pump since I was teenager pumping gas, and that was a LONG time ago!