Engine Braking, is it possible to over rev the engine?

I can't see slowing for curves via cruise control. I'm sure it can be done, but I'd much rather touch the brake (disabling cruise) and take over control myself. FWIW, when you use the brakes you're typically not actually applying the brakes, anyway: it's still mostly regen that's slowing the car.

 

And when hitting the brakes, you have the added benefit of actually warning your fellow drivers you are slowing. (Yes, rear ending you will technically be their fault, but it is much better not to bend all that sheet metal)

 

Common sense suggests that whatever action you undertake you do so with the full awareness of what is happening around you. I recently had a semi so close behind me that all I could see was a small portion of his grill, he could not possibly see what I was doing. I quickly changed lanes so he could tailgate the traffic in front of me.

It is perfectly acceptable to use cruise to slow down and it is equally acceptable to slow down using braking, based on traffic conditions. Failure to understand traffic conditions may result in bad things happening and your fault or not, dead is still dead.

 

That link is specifically for the GenII Prius. Different gearing shifted the magic speed up to 46 mpg in the GenIII Liftback. Magic speed shifted again for the 'v' and 'c'. While the concept is still the same as in GenII, I wouldn't use this link as a reference for the specific speed in other models.

 

Is any fuel being used at all? I would have guessed that just like coasting in gear in a stickshift, the wheels are turning the engine and no fuel is burned. I guess that's something else that could be confirmed with a scangauge.

 

The fuel is shut off to the ICE in several different circumstances. One of those circumstances is during engine braking, which also includes changing the valve timing to reduce stress on the engine.

 

I'm not really sure, just suspecting the engine can't be rotating without some fuel being burnt. ScanGauge does have some setting (Gallons per Hour??) that might show.

 

my scangauge quite often shows 0.2 l/100k while the computer is showing 0.0. I guess it's a question of which instrument is actually correct

 

My scangauge indicates that fuel is being consumed when using engine baking. I have a 2016 Prius. The MPG seems to vary between about 50 and 100 mpg. Maybe my scangauge is pulling my leg?

 

That'll depend on circumstances, engine temp, etc.