Save Gas at Signals : Neutral gear or Drive Gear

[kk]

hi all,

In order to save gas while waiting at signals - does putting the rogue in Neutal Gear helps?

Since it is not very practial to turn off the engine at each and every singal.

any helpful reply will be appreciated.

Regards,

[philipa_240sx]

Putting it in neutral may make a slight difference. Here is why:

When in drive, the motor is having to spin the torque converter (bascially a fluid coupling) against the now stopped wheels. This puts a slight load on the motor and the energy is lost as heat. When in neutral, the forward drive clutch disengages and the only load on the motor is the power needed to drive the CVT's hydraulic pump... which is very little.

It won't be huge, but it will make a difference and every bit helps. Idling in neutral should not harm the CVT.

Obviously you would be further ahead by turning the motor off. I do this all the time esp. at major intersections where stop light cycles are very long. I restart when the light turns amber for intersecting traffic, this way I am ready to leave as soon as my light turns green.

On the topic of hypermiling and the CVT...

One thing I DO NOT recommend is coasting in neutral with the engine off. Not only does this leave you without power brakes, the CVT hydraulic pump will not operate without the engine running and damage could occur from lack of lubrication.

[roguetoad]

Offing the engine (only while stopped, at rest as Phil says) is likely to not make much of a difference unless you'll be stopped for more than a half a minute or so.

The roadrats have been fixing our highway for over a month now and I tried a loop shutting off at each of three flag stops the first time and leaving it going the second time. made about 1 mpg difference. And that's assuming I was driving identically each loop which is hard to finesse for that extra tenth or so.

A couple fo other big factors are: 1) drag (remove anything on the roof), Keep the A/C off as much as possible and the windows closed.

But again, it's the driving style that'll pay the biggest dividends. We're now at about 1500 miles and haven't yet gone below 31.

[philipa_240sx]

That's great mileage Roguetoad!

Driving habits have alot to do with the widely varing mileage being reported. Being very conscious of your driving techniques can make a huge difference. Case in point:

My fiancee has a rather bad habit of not being able to maintain a constant cruising speed. As a result she is constantly accelerating/decelerating by 2-3 mph. As a passenger it is quite annoying... and it takes a huge toll on the fuel consumption of her Mazda. Of course she does not notice her habit.

[kk]

thanks for those replies...

observed one more new thing

in drive mode with breaks applied & in Park mode : RPM is about 700 RPMin neutral mode : RPM is about 900-950 RPM

seems that more gas is wasted in neutral mode...

quite interesting...

could you check if you all also find the same findings...

my Rogue is 3 days old...

[philipa_240sx]

in drive mode with breaks applied & in Park mode : RPM is about 700 RPMin neutral mode : RPM is about 900-950 RPM

seems that more gas is wasted in neutral mode...

Not really, although the engine is running at a higher rpm it is under less load so less fuel is used. It would be the same as running down a hill... it takes less energy than walking on level ground.

[kk]

okay sounds good... i will try and keep at neutral and save gas at the lights....

this is still my first tank... and gas mileage as per Mr. computer is 19.5...which is comparatively low compared to others.

have been driving mostly in city at max speed of 35mph - 40mph because of the 25mph speed limit

[Venom_Rogue]

I will have to disagree that putting in neutral will increase MPG on the Rogue.

I have a scan gauge installed in the Rogue and I believe because of the cvt transmission there is less load on the motor when the transmission is engaged than when left in neutral.

On all my other cars non cvt neutral helps a lot to save gas.

I cant remember exactly off the top of my head of the numbers, but in neutral the Rogue burns .35 gallons per hour (the rpms increases in neutral increasing load slightly). When left in drive and brakes applied the Rogue burns only .23-.25 gallons per hour (rpm decreases less load).

My Rogue still is under the 1000 miles mark and I can consistently obtain ~32mpg with 75/25 highway city driving. This is with a very good foot and being able to control the load. My GF who drives gets only 16-20mpg around town.

[mistergib]

...I don't know guys....it seems to me that unless the lights are extremely long, the amount of gas savings between idling ingear or idling in neutral would be quite nominal, more than likelynot even distinguishable....plus....take in consideration the wear and tear of going in and out of gear....although this wearand tear would be small, but I doubt not any smaller than the amount of gas that you think you might be saving??

I say it ain't worth it...(imho)

[roguetoad]

Right on, Phil. And one of those habits that'll waste a lot of fuel is constantly fidgeting the throttle. every little bit of pressure just ups the dinosaur bits into the injectors.

Another thing we've found over the years is that using cruise control up long grades will increase the fuel load over what you can do by slightly adding throttle with the cruise off. then there's the overzealous use of the paddles, too. Of course that's a lot more fun

You can up the mileage a bit with the paddles by short-shifting, as long as you don't overtax the engine.

i have to also feel that mistergib is right. Seems to me that's got to place extra wear on driveline parts.
Modified by roguetoad at 3:12 PM 7/7/2008

[philipa_240sx]

I was ignoring wear and tear on the transmission. Good points everyone.

Venom_Rogue, thanks for the scangauge info. You proved my assumption wrong with some hard data. Good work.

Personally, I still shut the motor off. But I usually do it at major intersections where I know the light cycle is very long >30 sec. Train crossings and lift bridges are another obvious place to shut it off.

[kk]

hey guys, thanks a lot for the response.... seems like it is not worth changing the gears to Neutral mode at the signals