Coasting trucks, what's the point??

I would agree with the momentum aspect, but probably 99.9% of the trucks doing this are governed at 65 or less. Until it drops to that speed, the engine is doing nothing. Then once it hits 65 it has to drop back into gear and pick up the slack

 

Eco-roll feature allows driver to select minimum and maximum deviation from the set cruise control speed when transmission shifts to gear to either increase the throttle or activate engine brake. But like you said I never truly trusted a computer and software with my life and an expensive equipment which would be hard to blame on the manufacturer in case it fails.

 

You are right about governing these trucks. Dealer wouldn’t ungovernate my truck completely and set it to the highest 80 mph allowed by the manufacturer.

 

In my Mack I can select cruise and brake targets. Usually the cruise is set at 70 & the engine brake at 74, but I've had it go well over 74 before the engine brake kicked on. I agree with not trusting computers lol

 

Ah, so they are smart enough. I look at this system the same way as the newer GM gas-burners that shut completely off at a stop light, and they start the engine back up when you give it throttle. Sounds great on paper, but completely F'n retarded in practice.

Then again, these systems in semi trucks have millions and millions of miles on them. It must be a net savings in the end, or they'd drop the system. At least I'd think they would.

 

I always thought it was just another thing idiots do with governed trucks to make themselves feel like super truckers.

 

You'll save $50 in gas over 5 years but we're happy to sell you a $700 starter every 2 years!

 

Exactly!!! My ex's Subaru keeps track of how much fuel she's saved with the autostart/stop. It's saved her 1.56 gallons of fuel, just over $3, since she bought it...TWO YEARS AGO

 

I thought they were set up so the only time they'd go to neutral was in situations where minimal throttle was required to avoid deceleration due to powertrain drag? In that very narrow range you could save fuel at idle, but as you point out, anything above that range the fuel is already shut off while the engine is in overrun.

 

Curious why you say that. I only buy dirt cheap 20 year old cars so I've never owed one like that but I borrow my friends car that does that and it's weird yes but seems to function just fine. And great on fuel mileage. Durango I think. Almost 20mpg. Drives fine afaik...