The driverless truck is coming...

[redpoint5]

Originally Posted by Xist

Are semis more fuel-efficient at 45 MPH?

...don't engines become more efficient with higher load, although that is overcome by friction above 55 MPH?

A semi is more efficient at 45 MPH because aero drag is the majority of what the truck is fighting against. Since the engine is a diesel, it suffers less penalty in the way of pumping losses.

[jcp123]

It depends on the gearing. In my truck I am either more or less lugging the engine in top gear at 45mph, or running a little bit over highway revs if I downshift one gear. I can et away with this if I am empty, but if I am loaded, an even number (40mph or 50mph) would be a better option.

[Xist]

Sorry, I neglected to mention that I read gearing was a factor. What kind of difference would you see driving a truck geared for forty-five compared to a normal one at 75?

[freebeard]

It would be slower.

"Peter built a truck for a man to drive, It's a pretty good livin' but it ain't no life..."

Lyrics: Bonnie Jean (Little Sister) by David Lynn Jones

Personally, I feel sorry for truck drivers and burger flippers, but stock brokers and lawyers? ...schadenfreude.

[Frank Lee]

Need moar like this one:

[freebeard]

For the younger readers:

https://en.wikipedia.org/wiki/Duel_%281971_film%29

[jcp123]

Originally Posted by Xist

Sorry, I neglected to mention that I read gearing was a factor. What kind of difference would you see driving a truck geared for forty-five compared to a normal one at 75?

Probably a good 3mpg or so. As mentioned, aero is a really big consideration, so you'd see some dramatic improvements.

[jcp123]

Originally Posted by Frank Lee

Need moar like this one:

Mm, yes. With a Detroit two-stroke, please

[UltArc]

So, so long left lane for passing...

From earlier articles I read on this, there wouldn't be a need for a driver, rather mandatory for their to be a pilot/maintainer on the vehicle.

I'm sure MPG will be a concern, but the big issue will be what is the standard speed for this platooning?

Example (Random numbers)
Company A has 10 trucks, they want them at 45 MPH.
Company B has 5 trucks, they want them at 65 MPH.

What is the standard? If we decide one, is there a penalty for not following it? Or will humans be required for not conforming to the standard? Will humans be allowed? Will we have no standard at all, and just a cluster of Platoon A doing 45 in the left lane, and Platoon B passing on the right doing 46, and Platoon C passing in the far right lane at 47, with Platoons D and E waiting to pass set at 48 and 49...and me screaming because I'm trying to EOC down this 8% grade with yahoos braking all the way down...

Also, how are we identifying the balance of the load? (yes, "haha, thats what she said" *sigh*) Will there be smart trailers?

I see the possibility of this occurring, but I have a hard time seeing it in reality. My biggest concern is balancing government regulation to protect the people (keep businesses in line) while not making poor decisions about it/going way to far with what and how they regulate.

[chefdave]

Frank lee this would also sort out lane disapline,driving at 40mph in centre lane, using mobile phones etc etc. Bring it on.