tmux

Just for fun, I tried some hypermiling techniques such as shutting off the ignition when coasting to a stop or at red lights.

One time, I tried to engine brake with the engine off and going ~40MPH. However, when I shifted into a gear, the engine jumped back on by itself. It's obviously designed that way but is it bad to take advantage of that often?

There are instances in which I don't shut off when there is a good chance the light would turn green before I stop. However, if I take advantage of this auto-on capability, I wouldn't have to stop along the side just so I can restart.

In before the "why do this with an Acura" questions. Just trying it out for fun, curious how much of a difference it would make in MPG. I have some long red lights (sometimes thrown off by a train going along the middle of the road), and I don't need to burn gas just waiting.

cu2wagon

1. You're going to wreck you car. Not ruin it, you're gonna crash.
2. Yes, the engine starts back up when you are rolling and let the clutch out in gear. It's like push-starting your car at 40 mph. Won't really hurt anything.
3. You're going to crash.
4. There is no four.

tmux

Relax, pretty much only way I would crash is if the brakes go out, which would be bad in any situation.

cu2wagon

But with the car off, you lose power assist functions. You're adding unnecessary risk.

Your call, though.

I'd be in to hear your results though. See how much you can really affect the mileage by doing this. Post back when you have data.

CommonSense

CommonSense is here!
When the ignition is off, there is no vacuum assist!
Common sense says NOT TO DO THIS!

cu2wagon

I think I'm going to like you.

ssjoeboe9

lol mods are going to ban you cause of making two accounts lmao

cu2wagon

Bring it on Mods!

cu2wagon

PS. I'm too lazy to do that.

opboarding

Turning on and off the car is too much work. I just attached a sail to my car and let the wind do all the work!

wreak

With the ignition off and rolling at 40mph... won't the steering wheel lock if you try to make a quick maneuver?

CommonSense

Common sense says: Yes!

CommonSense

Common sense says: Keep it in gear and coast to said light. when in gear and coasting, fuel injectors are OFF! when fuel injectors are off, NO FUEL IS BEING USED!

thoiboi

starter

NBP04TL4ME

Completely depends on what key position you are in, but either way not too smart to be doing this regularly. Also adding additional wear while restarting engine via the clutch @ 40 MPH. Neither are the end of the world and it's the OP's car, but not something most would be doing regularly. :shrug;

ssjoeboe9

Actually, your injectors are not off. You are idling just like neutral at a traffic light... well kinda. once your RPM drops low enough

CommonSense

Car engineers say otherwise.

ssjoeboe9

lol firstly I edited my post before you quoted me

secondly your quote says while the car is in gear

CommonSense

Post #13 also says; in gear

opboarding

I like this commonsense guy.

ssjoeboe9

commonsense is right

lol

CommonSense

It pays to double check...

(wait, that's not my tag line.)

Flipster23

iTrader: (15)

Commonsense is now banned.

His commonsense must have been lacking to make 2 accounts.

Flipster23

iTrader: (15)

Soooooo you didn't want to pass 60k huh...

TacoBello

I guess common sense isn't that common anymore...

cu2wagon

Whu...

Flipster23

iTrader: (15)

Bring back soundmasterbater......

tmux

No power steering but that just means I have to use 2 hands instead of 1 in the rare occasion I need to change lanes when off. I've driven cars before power steering though so it's not too big of a deal.

No power brakes, I didn't really notice much. Your foot is powerful and the gears are light on neutral.

Most of the time when I do shut off, I do it after stopping. Just experimenting more recently with long cruises to stop when I won't be needing to accelerate.

I'll see how long the starter lasts, other sites say it's not an issue with modern cars.

Data is hard to come by as city driving is so random. Savings minutes of idle burning is pretty clear though, can easily surpass an hour a week as it can be 2min+ at a single light. It's why many newer cars have auto-stop.

And yes it can get tedious stopping and reigniting so you can skip it and still get a nice boost from coasting more often. On my old Civic hybrid, it was around a 10-15% difference in MPG when coasting often vs rarely coasting. Can easily be over 20% depending on the route.

tmux

Common sense says: when the engine is running at 1k RPM sustained, it is using gas.

CommonSense does not believe in Newton's 1st law of motion.

Common sense is still common but CommonSense is not. Sometimes, common sense is only common after passing physics.

ssjoeboe9

I made the same comment, but he (justin) is saying if you leave it in gear your injectors are off, which is true. If you coast in neutral then yes you are basically idling... anyway you probably read it the same as I did.

tmux

That part is immaterial, he said no fuel is used, which is false. Coasting in gear is also inefficient. He probably thinks he can jump to the moon if he didn't stop himself.

BROlando

No, actually. You need to take the keys out of the ignition to lock the steering.

BROlando

Leaving a car in gear as you slow down will use LESS fuel than letting it idle out of gear as you stop. Idk why that is being argued.

cu2wagon

Negative. It locks in the 0 position. I don't recall, but it might lock in the I position as well.

But technically, there isn't a really a difference between position 0 with the keys in or out.

thoiboi

If you can take your key out of the ignition while your car is in gear, you need a new ignition

cu2wagon

But that's what happens every time you park and get out (with a MT).

Ignition off, in gear, keys come out.

Or do you mean ignition on, in gear? Because yes, keys should not come out.

BROlando

His car is a MT. And no. The steering does not lock in the 0 position unless you take the key out.

Try it.

After the steering has already been unlocked, turn your key to 0 (but don't remove the key). The steering wheel still turns.

Now remove the key. Try turning the wheel. It locks.


Also...you don't need to turn the key to 0 to turn off the car. In fact, after turning off the car, one can flip the key to the "run" position so that the odometer still counts miles. As long as the car is not in gear or the clutch is pushed down, the car won't start....it will just coast with the engine off. Remember he has a MT.

For an automatic, if you flip the key to "run" after turning it off, the car wont start back up even if it is in gear. You can't roll start an automatic.

EvilVirus

iTrader: (8)

OP buy a Nissan Leaf. Problem solved

avarela86

Newer BMWs do this standard sell the TSX and get one of those! :-) for what the TSX is it gets pretty decent gas mileage. Doubt you'll break any records trying hyermilling techniques. Whatever you do keep safe on the roads! :-)