No, safety is an issue, not just an argument FROM myopic SUVers. This is an argument from someone who has had to accelerate WOT with no warning, in more than one instance, to keep the wife and kiddies from joining me in a trip to the ditch because of some idiot doing everything but drive his vehicle tried to drive where I was. Had I been running in neutral or engine off in any of those cases, I'd have been in several accidents. I'm glad you've never had an issue with this, but it may happen at any time you are on the road. The only way you could guarantee to never have this as an issue is if you only did it when there are no other cars near, and as crowded as the roads are today that means you might be able to do it once or twice a month.
Sorry Telco, I'm not buying the 'having to accelerate at WOT to avoid an accident' arguement. In over 20 years of driving, I have never needed to accelerate to avoid an accident and only been involved in one (that was 100% my fault). I'm not saying that it didn't happen to you or that it can't save your butt, but it is such a miniscule point of contention when you consider that the majority of drivers will simply nail the brakes when faced with a possible collision.
I agree that coasting leaves a driver slightly more vulnerable to surprises, but most of the time whether they are in-gear or not will make little difference to accident avoidance ability. More often than not, braking and or swerving is the more prudent thing to do and the automatic reflex for most.
I am more concerned with "Is it safe" than "Is it legal". The laws and statutes are their because some dink dong, at some time, did something stupid and got hurt. If the person hadn't done something stupid, they wouldn't have been hurt and the state would not have had to create the statute to protect us from ourselves.
Some cars have power steering, power brakes and automatic transmissions. In many of those instances it is probably less safe to be doing some things, like coasting with the engine off. In other cars, they don't have those things and if conditions are safe, then I don't have a problem with coasting with the engine off. However, I won't do something if I don't think it's safe, even if their is a statute that says I could.
Snax, I hope you never are in that situation. Been driving over 20 years myself, with a lot of that cross country driving. Being able to accelerate with no warning has saved my butt many times, and in a few of those situations slamming on the brakes would have caused an accident, not prevented one. On the other hand, slamming the brakes was the correct action. Knowing that the impulse of people is to slam on the brakes when in a bad situation is what made it work. I'd just rather have the option of brakes or gas, not be stuck with one option in an emergency.
Gary, both sides of the argument have been presented on whether neutral or engine off is safe. IMO, it isn't safe to go engine off at all, and neutral is only safe when nobody else is around. Others think nothing about doing it. I'd suggest trying it out and see how you feel about it, then go from there.
Skewbie, as I am part of the natural course of things, I see no reason to not use what's available. I feel that those who think that any use of natural resources is bad should stop breathing the air, eating the plants and drinking the water because that is a resource waste too. Just think, every breath you take is slaughtering millions of bacteria! And who says that lettuce didn't feel pain when it had its head cut off!
My thought on the "need to accelerate" thing is quite simple. My car is not exceptionally slow by any means, and I don't thing I have enough acceleration "in reserve" while cruising in top gear without downshifting to make any difference in an accident. If I would have to downshift to get any quick acceleration out of the car I can do that just as easy from neutral or even from EOC.
I also think that when you hypermile you are forced to pay more attention to the road around you. Anticipating traffic or terrain changes we ahead is one of the best ways to improve your mileage, so if looking for coasting spots makes you more alert it will probably help you avoid an accident more than some extremely rare situation where a tiny bit of acceleration helps you avoid one.
As far as the legality of hypermiling, it really depends on the technique. I find myself rolling through stop signs or right turns on red a lot so that I can stay in second gear, and that is most definitely illegal. I also got a speeding ticket the other day while coasting down a hill because I didn't want to waste my kinetic energy for the following up-hill (I also thought the speed limit was 5mph faster than it was, oops). So clearly illegal things you can do trying to hypermile, but those things are not inherent to hypermiling in general.
I think Telco's points are valid, but the impact to safety will depend greatly on the car as Gary pointed out. Our Mazda5 remains perfectly controllable in neutral with the engine on, and it lacks the power to accelerate out of any emergency situation without allot of warning, so coasting with the engine on is no less safe than keeping it in gear. Engine off however requires significantly more steering effort, and there are only about two good stops in the brake vacuum reserve. I only do it when I am alone in the car on straight highways for those reasons.
My MR2 that I am converting to electric however has virtually no vacuum assist on the brakes and manual steering. It was never a source of overwhelming acceleration either. So engine off or on is of little significance (and one of the reasons I chose it for my EV project).
I think if you look into the coasting engine off laws, you will find they are ancient! Back when engine braking was very important because of the poor quality of brakes these laws were useful. Can't see the point of them today. As it was pointed out hybrids do coasting, so why not us.Having run out of vacuum quite often in the Metro it has never been a problem to stop. Just a little more braking effort.
Having had evasive driving training 3 times at GM MPG. I have been taught to stay off the brakes to drive around accidents, but not accelerate through them. That being said I have accelerated out of skids in the snow. How about others in the snow belt?
As to legality. It's illegal to drive 80 to 90, but no one seems to care about that much around my area. So don't feel to bad about coasting! If you feel uncomfortable doing it thats no problem either.