Hi,

Has anyone noticed any difference in fuel economy between automatic mode and shifttronic?
I noticed that both shifttronic and auto jump to 5th at 60km/h but once I get it, shiftronic keeps 5th even when speed drops to 50km/h, while auto down-shift to 4th..

Robert

:)

Good question Robert. I wonder also. :unsure:

I wish our Azeras had the instant fuel economy readout feature that some cars have.

Perhaps someone will have the equipment to be able to check whether
or not using the shiftonic feature as I do helps or hinders city F E.
I like to start off from rest in second gear (unless it's an uphill start) and 'force'
the transmission to upshift to each higher gear as early as it will possibly do.
I find that the T/C will lock up in fourth gear very early and remained locked
up as the transmission upshifts to fifth at about 38 mph or 60 kph.
As you know, our Azeras have beaucoup torque even at 1000 rpm, and
mine seems to love pulling like a John Deere at those low rpms! :whistling:

My question therefore is: "Am I getting better F E in the city by doing this or
would I be better off simply allowing the transmission to do its own thing?"

:innocent:

I find it better to stay in Auto that way I can bump it into neutral to coast to stop lights and down hills. If your in Shiftronic you have to make the switch first. Plus if it in Shiftronics mode and your in 4-5 gear coasting the car will use engine torque to slow your speed when going down hill. This keeps your speed from creeping up on long down hill coast, but hurt your MPG in town if you don't get it into neutral.
Just my 2 cent. :57:

This post has been edited by Qman: Sep 30 2008, 12:11 AM

:)

You are wrong!

Coasting in neutral is not only illegal but dangerious. Doing so uses more fuel
and also braking to stop your vehicle which wears the brake pads out faster.

When coasting in neutral, what keeps your motor running? Gasoline!
So how can you say that you are getting better fuel economy when
coasting in neutral compared to allowing the motor to be driven
by the motion of the vehicle which uses absolutely NO fuel? :whistling:

Think about it. :wacko:

Best fuel economy......Auto the tranny is programmed for this

Even though in shiftronic the reader reads 5th below 50Kmh, the tranny will be in a lower gear, it just doesn't show in the window. You can easily test it yourself by accelerating and count how many upshift you make.

This post has been edited by Pelikan: Sep 30 2008, 09:06 AM

:)

I disagree! :innocent:

Slowing to 30 mph, ours is in fifth gear and the T/C is still engaged. The tach reads 1000 rpm.

Do the math and you too will know that I'm correct. :whistling:

A ScanGauge II will tell you instantaneous miles per gallon and several other parameters affecting fuel economy (manifold pressure and throttle position, for example), and can be used in any modern vehicle for many years into the future.

Bud H

First off it's NOT illegal, Manual Trans you do it all the time. Two, Manual Trans. typicaly get better MPG then autos in same make/model car. Three, in an Auto Trans. below 30-0 mph the engine is not providing any engine drag, hence Gasoline is still being used. Plus at stop lights in auto in gear what keeps the motor running, Gasoline. When in Neutral you remove the fluid drag in the transmission and then engine is working less, less Gasoline is used. Read my first reply you will see when going down hill, coasting in gear your car adds engine drag if the car is speeding up, otherwise the engine is just idling using the same Gasoline as in neutral.

Brakes, coasting your not using your brakes. When you see a light changing up ahead slip it in to neutral coast till you need to brake. If your in gear you may come up short because of the engine drag and need to use the Gasoline to get to the light. but you still use the brakes to stop.

The Highway safety dept. does not recommend coasting with an Auto. Transmission because you may need to be in gear to speed up to avoid an accident. This maybe a safety issue but can be done under the right conditions.

Q.

I would have to say that I've noticed better fuel economy when the shifter is left in auto mode. I think that's part of my problem of seeing only 15.5 average FE with my daily commuting (usually 85-90% city/10-15% highway).

Using it in manual mode usually means your shifts are going to be more aggressive which will burn more fuel.

Today's automatic transmissions coupled to computers can detemine way, way before the human mind when to shift gears. That is why today's automatics are more fuel efficient than manual transmissions. If someone delibertly "tests" a manual for fuel economy as Consumer Reports recently did, they can nudge the results. However, 99% of drivers 90% of the time will not drive a manual in the most economic mode. I have driven manuals for 40 years and still have a manual pick-up.
For the same reason, the shiftronic is not anywhere as efficient as automatic.
I had a car with an instant MPG readout. It was useless and dangerous. Rather than looking at the road, mirrors or gauges, I would look at the MPG up hill, down hill, over the hill, etc. I got 99 MPG down hill and 5 up hill. What did that tell me-nothing.
Having been a certified Defensive Driving Course instructor, you should NEVER put your vehicle in neutral when it is moving. Manual or auto. You have effectively lost control of your car by doing so.

Hey Bob,

The only thing I can hope when someone mentions a manual being in neutral while moving would mean havin the clutch fully depressed. I know in all the years I drove vehicles with manual trannies...coming to a stop I would downshift to a degree, but then as I would come closer, I would put the shifter in 2nd and keep my foot on the clutch and use the brake. That way if the light changed to green before I came to a complete stop....I would already be in 2nd for a smooth start. That's a neutral as my vehicle would ever get while in motion.

Mike

Bob,

I think you misunderstood what I was saying the last sentence I stated "The Highway safety dept. does not recommend coasting with an Auto. Transmission because you may need to be in gear to speed up to avoid an accident."

:)

I don't know of anyone who can make so many incorrect statements in one paragraph that are simply WRONG! :wacko:

First off, it is illegal at least here in California and I'm sure in many other states as well.
From the California DMV motor vehicle code:
Coasting Prohibited 21710. The driver of a motor vehicle when traveling on down grade
upon any highway shall not coast with the gears of such vehicle in neutral.

Second . . some drivers typically do get better mileage with a manual transmission, but not all do.
It depends on who is driving and IF they know what they are doing.
I don't know about your Azera, but mine has an automatic, and I
thought this subject was about the habits of people who drive Azeras? :unsure:

Third . . my Azera transmission below 30 mph does provide engine braking and while doing so,
there is absolutely no fuel being injected until just above
the point where the regular idling rpm is reached.
This has been proven to me on many previous vehicles that I have driven that
have the "instant" fuel economy feature on their computer readouts.
Have you ever done that and seen a reading of 99 mpg? The only reason that reading is not
even higher is because the computer does not have a higher number programmed into it!

"Brakes, coasting your [you are or you're] not using your brakes. When you see a light changing up ahead slip it in to neutral coast till you need to brake. If your in gear you may come up short because of the engine drag and need to use the Gasoline to get to the light. but you still use the brakes to stop."

True, when you are coasting, you are not using your brakes, but what about
when you need to slow down or stop? Do you simply rely on your brakes only?
How many miles do you get on your brakes in so doing before they are worm out and need replacing? When you are 'coasting' in neutral, what is keeping your motor running?

When you must use your brakes to slow down or stop, do you think
being in neutral helps you stop better or sooner or more safely?
That why there is a DMV ruling prohibiting coasting in neutral.

Maybe there are no down grades or mountains in WI, but where there are downgrades,
truckers use what is known as a Jake Brake to help them keep their rigs under control.
The fellow that invented that devise coined a phrase: "Even a mule works both ways."

Being a retire professional driver gives me a slightly better insight into what I am talking about.
What I cannot understand is how you learned so many completely wrong
and unsafe 'facts' that are simply just wrong and incorrect.

Did you know that with some automatic transmissions, there is
not proper transmission lubrication while coasting in neutral?


That's incorrect also.

The first part of your statement is indeed correct. However . .
The reason the highway safety department does not recommend coasting with an automatic
or any transmission is not to "be able to speed up to avoid an accident."
The reason is, to do so is unsafe because of the fact that you loose control, period. :innocent:

Carry on and believe what you like. I tried, and that's all I can do.

:amen:

This post has been edited by snaglepus: Oct 1 2008, 10:00 AM

snaglepus,

You won, I'm sorry. :57:

http://www.wisebread.com/maximize-your-car...ith-hypermiling

Take note of your own driving habits. The fundamental principle of hypermiling is to use all of your car's energy to generate forward momentum. By leaving ample space between yourself and the car in front of you, there is enough time to coast to a stop and avoid stepping on the brakes.

http://www.wikihow.com/Save-Money-on-Gas

Anticipate the stop signs and lights. Look far ahead; get to know your usual routes. You can let up on the gas earlier. Coasting to a stop will save the gasoline you would otherwise use maintaining your speed longer. If it just gets you to the end of a line of cars at a red light or a stop sign a few seconds later, it won't add any time to your trip. Ditto for coasting to lose speed before a highway off-ramp: if it means you catch up with that truck halfway around the curve instead of at the beginning, you haven't lost any time. In many cities, if you know the streets well, you can time the lights and maintain the appropriate speed to hit all green lights. Usually this is about 35 to 40 MPH.

http://www.auterraweb.com/

DashDyno SPD is an exciting new in-vehicle mounted automotive computer. It combines a trip computer, vehicle gauges, OBD II scan tool, data logger and performance meter into one compact device.

Measure instant and average fuel economy, data log engine sensors, measure horsepower and torque, trigger alarms lights, and diagnose your Check Engine light. Connect a laptop to your vehicle using the Windows software and DashDyno PC pass-through mode for even more advanced diagnostic capability. DashDyno can do this and much more.



Sorry, I didn't Known your states laws. Is it only highway or all roads?

By the way you do use gas when in gear coasting. Here in WI, we have winters and IF the forward momentum is the only thing turn the engine then what happens when you cross an ice patch, the engine stops? No there is always some gas going to the engine.

Lets just stay on topic!
and stop....
(IMG:http://i37.tinypic.com/2qcr22h.gif)

Q.

This post has been edited by Qman: Oct 1 2008, 08:32 PM

:)

I am on topic. Wasn't the topic F E ?
I am certainly not fishing. If I wanted to do that, I'd go up
to my camp on the WPG river North of Kenora, Ontario.

Yes, the California DMV code applies to all public roads and highways in this state and all
30 million vehicles licensed here in California. Most of the licensed drivers in
this state of 35 million people abide by those rules.

I say again, with any fuel injected engine, there is no fuel injection at all as long
as the engine rpm is above the idling rpm and no throttle is being applied.
I don't care about your icy roads. When you hit a batch of ice (How often does that happen?),
do the drive wheels simply stop turning like you are parked? If that is so, then
the motor is down to an idle, and of course there is fuel consumption.
But what does that have to do with the price of tea in China?
We are not talking about fuel economy when driving on ice. Who cares
about F E when you are in such a dangerious road enviroment?

I am fully in control of my nearly perfect driving habits, thank you.
As stated earlier, I am a retired professional driver and have been driving for 60 years.
There is not very much that I do not know about driving, modesty aside!
I am sure that I do learn something new every time I drive, whether I realize it or not.
The day I say I learned nothing is the day I want you to shoot me!

Like I said, I have tried but failed to get you to understand, and for that, I am sorry.

Carry on, and watch those dangerious ice patches! :whistling:

:amen:

This post has been edited by snaglepus: Oct 6 2008, 12:28 PM

I experimented a bit this weekend. I drove the entire weekend and left the shifter in auto mode (it was difficult to do, but I did it). Normally, about 95% of my driving is with the shifter in manual mode and my normal FE returns for my weekend urban driving (combo of city & highway) hits about 16-17 mpg.

Just to give you an idea...I live in the DC metro area, so it's easy to go from highway cruising to block to block stoplight type driving in a matter of minutes.

Anyway, with the shifter in auto mode the whole time, I noticed an increase in my FE to about 20-21 mpg.

Did I change my overall driving habits, not really. I drove at speeds I normally drive at. I took off from starts as I normally do, but now...coming to stop relied solely on the brakes.

This was, in no way a scientific experiement. Just some real world driv