OK to coast downhill in Neutral?

[NCC1701]

I had been coasting in neutral to stops. Not on hills, I'm in Florida. But, from 0.2 to 0.4 miles when I see an unavoidable stop ahead. The car obviously coasts much better in neutral than in gear. I've read most of this post. I'm having large second thoughts about my coasting.

There is a 14 mile stretch between Cripple Creek & Colorado Springs where I used to coast, motor off, in my 1969 Ford Custom.
Not my car.

[headless]

this topic has opened up a whole can of worms.
If you are coasting down hill in neutral to save fuel, YOU ARE USING MORE FUEL, FACT.
The engine has to use fuel to tick over in neutral,
it does not use any fuel if it is coasting in gear.
Another thing is, if you need to accelerate out of trouble all you do is stick your foot down on the loud pedal, and I would'nt advise going in and out of gear while travelling, clutch and gearbox are going to take a hammering.
I have owned a smart for four and a half years, so I feel qualified to answer Ellis.
ps. so far after four and a half years, zero defects, just thought you would like to know about long term ownership, as you are all newbies to smarts.

[Kermit]

I'm uneducated on the roasters since we don't have them here in the US. Do those have the Mitsubishi motors like the 451's? How about the gearboxes? Are those the same maker between the 450 & 451? Just curious.

[SuperGeek]

Originally Posted by headless

ps. so far after four and a half years, zero defects, just thought you would like to know about long term ownership, as you are all newbies to smarts.

Thanks for that point. We only got a 2 year warranty in the USA, and some of us worry that the machine will die on the first day of expiration. I paid extra for the 5 year extension just in case, because in my experience paying for repairs on an emergency basis and scrambling to get the funds costs about 3 times as much as a warranty when you're not prepared for it.

Granted, the 451 has a different engine and maybe transmission... but the most of the rest of the car's probably pretty close to the 450s. Knowing that a 450 lasts 4+ years without a defect means a lot to confidence in the 451.

[unicycle]

Originally Posted by headless

this topic has opened up a whole can of worms.
If you are coasting down hill in neutral to save fuel, YOU ARE USING MORE FUEL, FACT. The engine has to use fuel to tick over in neutral, it does not use any fuel if it is coasting in gear.

I'm not sure that's true. I have a ScanGaugeII. When I shift from D to N, the mpg's go way up -- generally in the 200 mpg range. Then when I shift back to D, the gauge temporarily reads 9999 (as it does whenever I take my foot off the gas). But as soon as the gears kick back in, my mileage goes back to whatever mpg's I'm getting at that moment.

[headless]

Originally Posted by unicycle

I'm not sure that's true. I have a ScanGaugeII. When I shift from D to N, the mpg's go way up -- generally in the 200 mpg range. Then when I shift back to D, the gauge temporarily reads 9999 (as it does whenever I take my foot off the gas). But as soon as the gears kick back in, my mileage goes back to whatever mpg's I'm getting at that moment.

The scanguage reads off the OBD port, and as you are taking the car out of drive the scanguage is confused as it thinks the car is stationary, so it gives a false reading, but when it is in gear it is being sent the correct info, the scanguage is ok, it gives you a good idea of what is happening, but it is not foolproof.

[headless]

Originally Posted by Bum-bling-B

I'm uneducated on the roasters since we don't have them here in the US. Do those have the Mitsubishi motors like the 451's? How about the gearboxes? Are those the same maker between the 450 & 451? Just curious.

The roadster has the same engine as the 450, the 700cc suprex turbo, with Mercedes Benz on the rocker cover, but with 81bhp as standard, but who has standard anyways, the box is 6-speed sequential, with auto and manual mode, but auto mode is rubbish, so we use manual mostly.
Hope this helps.
El

[Jeanclaude]

Originally Posted by headless

The scanguage reads off the OBD port, and as you are taking the car out of drive the scanguage is confused as it thinks the car is stationary, so it gives a false reading, but when it is in gear it is being sent the correct info, the scanguage is ok, it gives you a good idea of what is happening, but it is not foolproof.

Here is what your scangauge is trying to tell you; the reading that you are getting when you shift into neutral is telling you that if you continued at your current speed with the engine idling, the mpg indicated on the scangauge at that moment in time would be actual. In other words, if you could continue to do 65 mph with your engine idling, you could conceivably get 200 mpg.

When you shift into neutral, the scangauge does not think that the vehicle is stationary, it is still reading the speed sensor (and other sensors) and knows that the vehicle is running and rolling.

When your scangauge reads "9999" it is telling you that the injectors are shut off.

[forestacademy]

Wow you woke up a year old thread to say that. You are at the center of the universe arnt you?

We covered that detail in this thread
http://www.smartcarofamerica.com/for...53/index2.html

[gamernotwatcher]

To chime in here, ahh the art of hypermileaging, before shifting back into Drive, I have found that you need to be get the RPMs of the engine back to where it will be before shifting, or you are ruining your car.