Why don't trucks go 55 for fuel efficiency?

You slow the flow. Sure. But I don't think it's enough to compensate for longer run time.

Definitely not in the mountains.

Between 55 and 70 for instance.
1,000 miles is 4 hours difference.

Missoula to Boise is an example. The short way is 450 miles and 15 hours. The long way is 600 miles and 10 hours. Back when the speed limit was 65.

 

I’m not sure what way you were going to Boise to have it take 15 hours. Lol. We did that all the time, down 12,13 and 95 with particle board to Meridian and it was 390 miles and took about 8 hours.

 

Given the same final gearing-in other words using the same gear in transmission- the engine will turn the same amount of revolutions per mile whether it be at 1000rpm or 2000rpm or 10,000 rpm. One revolution of the crank will turn the wheels the same amount.

 

Are you actually arguing that a truck getting better mpg, meaning it's using less fuel per mile is going to burn more fuel over a given distance because it will take more time? Do I really have to do the math on this? *facepalm*

 

Another aspect not included in my original post....

If a driver makes 60 cents per mile running 750 miles, how much less would he make at 55? 750 / 11 hrs = 68 mph.

11 hours at 55 even with no slow downs equals 550.

73% as productive. So... will that driver find it favorable to be over the road at that point or will they take a local job?

Someone has to be over the road so do they request a 27% increase in pay?

Now all of a sudden driver pay has to go to .76 per mile in order for him/her to make the same and be home even less from his wife and kids.

75 at 7.5 vs 55 at 9... do the savings make up for that alone, before loss of revenue even happens?

I could do the math but don’t feel like it.... just another aspect.

 

yes.. do the math.

 

.

You packing in a car? LOL

Next time drive a semi. Loaded. LOL.

 

Nobody gets, or at least tries to get, down the road faster than the governed mega carrier.

 

I guess the continued higher rpm isn't harder on the engine, it's components, and the rest of the truck as well???

Once you're above 72 mph, especially if it's hot, you're literally peeling rubber off of your drives as well due to the friction.

So that's another couple thousand a year just in unnecessary tire wear.

BUT

For the big timers here, couple thousand is laundry money.

I just hope to someday be able to live outside the truck with the cat, and not have to eat Beefaroni.