I have been working the ECO mode a bunch recently trying to get my MPG better (I have AWD RX350 2010, best yet is 21mpg after 5000 miles)

So I go into cruise control (which is goood for economy right ?- no herky jerky) ECO light is on, bargraph shows nothing (you can toggle to bargraph from the steering wheel while in cruise)- ie implies good economy. But I am doing 60 mph so clearly I must be using some gas - so why is the bar graph at zero?

Then when I step on gas while still in cruise, the ECO green light goes off - as you would expect. But the bar graph still is on zero??

And when I use the cruise lever to accelerate while in cruise (using the + function) the ECO light stays green - despite the fact that the acceleration is at least the same as my pedal acceleration above.

So what gives? Is the whole ECO indication bogus? Or do I need a service check?

Please let me know if you experience the same behaviour..

 

Wow 69 views and no responses.

Does no-one else have this problem or know they have this problem? Or is it too complicated for you to observe that there's a problem?

Very simply put for the inattentive: When you are in cruise control with the eco light green, does the light go off if the gears kick down as you go uphill. Mine doesn't.

 

I turned the light off shortly after getting the car. Then a few weeks ago turned it on, and tried to drive in a manner that kept the light on. My MPG went up by about 2, and the fun factor went to ZIP, NADA. For the extra $100 a year I'd be saving, I drive it like I stole it, and couldn't care less about that light.

You're assuming that the ECO light programming and that graph programming are tied together, which they may not be. It does make sense that the light is programmed to stay on while cruise is on, to get you in the habit of using cruise, like Pavlov's dog. But I do think you're way over-thinking how sophisticated that light and graph are.

 

I have a 450h so this is not a direct comparison.

When using my cruise control the ECO light does go out when the venicle is accelerating at a higher rate. It comes back on when it "settles in".

Where you have a tachometer I have a Hybrid System Indicator gauge. Anytime that this gauge moves out of the green and into the white "power" area, the ECO light goes off.

 

the ECO bar graph does not represent how much gas you are using. It represents how efficient you are driving. Therefore, when you step on the gas a little, even though you are using more gas, the bar graph doesnt have to change because it just means you are acelerating economically.

 

The 450h is much more sophisticated in its use of indicators and lights to reflect what's happening, like the Highlander Hybrid I owned before the RX350.

 

I watched my "bar graph" closely this weekend. When using cruise at about 70 mph, the graph shows about 25 mpg. Using the cruise lever to slow down, the graph zooms up to 60 mpg.

I don't think yours works. Or at least not like mine.

 

^^ there are two different bar graphs. One is instantaneous mpg and it is the bar graph with the 30, 60, 90 markers. The ECO bargraph doesnt have any markers.

1st one looks like this


I think we are talking about this one (2nd one)

 

From my observations this weekend it appears that while in cruise the eco bar graph is turned off (even though it doesn't say off) while the eco light is still on.

 

My guess is that the ECO indicators are not valid when in cruise control, which is really a non-issue for me.

The purpose of these indicators is to get the driver to save gas while actually operating the gas pedal anyway.

 

Cough,

Something is wrong with your bar graph. I've noticed that there is a slight lag with the bar graph, but you should not see an empty bar during cruise control for more than a few seconds if you are not accelerating or driving up a sleep slope. Have it checked out during your next service.

 

Zak21 has the same issue as me. I was referring to the ECO bar graph. Are you saying your ECO bar graph -not the MPG bar graph (see above) - works in cruise control?

 

So I'm confused, Cough. Do you have an RX 350 like you stated in your first post, or the 450h?

 

No, I thought you were referring to the MPG bar. Sorry for the confusion. During cruise control, the ECO bar disappears.

I ignore the ECO bar anyway. The ECO bar/light are less relevant than the MPG data because one's driving is efficient or good "ecologically" insofar as it is yielding good gas mileage. In other words, the ECO indicator is a proxy for mpg.

 

Ever since cruise control has been a part of the automobile, it was well known, documented and still is that "it" is more efficient and yields more MPGs than the unaided driver. Evidently, the Eco graph and light are there to help the driver achieve (teach) higher fuel economies, and not the cruise control system. So, displaying the cruise control's performance is completely redundant, to say the least...