Legality of Hybrids re coasting
 

Hybrid vehicles were a legal game-changer, I hear. Didn't hybrid auto-makers have to wangle some new interpretations of the anti-coasting laws at the federal level in order to pre-empt state laws, because the technologies obscure the definition of "neutral"? This might create legal openings for coasting in gas and diesel autos where coasting is restricted.

A law is only as good as its enforcement.

I will also say that with the proper use of DFCO, you don't need to neutrally coast. I guess this would apply to people that do EOCing (engine off coasting) though I still have issues with trans wear doing that personally.

I haven't heard of any need for special laws resulting from hybrids. It is my understanding that common hybrid behavior is that you have to hold the accelerator pedal at a certain position to get neutral coasting; any less and you get braking (similar to engine braking).

However, regardless of interface issues like that, the laws about coasting don't say that you can't have your vehicle roll with no resistance from the drivetrain; they say you can't roll with your drivetrain disengaged. The electric motors in a hybrid are always engaged, are they not?

Well, maybe not...do start-stop "mild hybrids" without electric motors neutral coast?

Even if they do, the legal system may not handle the issue at a technical level, but rather at the level of the driver's behavior; as long as it's in "D", or anything other than "N", it'll be tough to blame anybody for coasting.

As for DFCO...it's totally not the same and is not good for the same purposes as neutral coasting or EOC. DFCO is great when you need to discard some energy; you get to recover some of it to turn your engine during that time instead of using fuel. It's perfect if you need to control speed during a hill descent or while approaching a stop; any time you might otherwise need the brakes. However, if you are NOT interested in losing some energy, such as during pulse & glide or a mild descent where aerodynamic drag/rolling resistance alone will control your speed, you save more fuel by neutral coasting (and even more with EOC). DFCO in that situation reduces your speed more and requires you to later spend fuel to re-accelerate, more fuel than idling the engine in neutral would have cost.

Legality is the issue though. They will never be able to enforce it on someone who is just driving along. In the event of a crash, under certain circumstances they could potentially find out and use it to blame someone. That kind of law became standard when braking systems were lame and engine braking was much heavier in any gear because overdrive gears didn't exist, and you needed engine braking to avoid crashing on any long descent or in the event of a (probably common) brake failure...and if you crashed like that then the law probably would get used against you.

I recommend following all laws all the time, even unfair ones. If a law is unfair then ignoring and disobeying it only makes things worse (a tangent rant explains why but I won't continue lengthening this post and going off-topic with it).

I coast by cops all the time. I'm not exactly concerned about it.

On an unrelated topic, this thread probably needs to be moved.

Thanks, I didn't even notice. Moved.

But, if you plan to obey them in the future, you should work on changing them. Laws are not commandments of God, they are created by humans, not more and not less than ourselves.

:thumb: That's where my rant would have ended up.