I noticed that brake operation will effect the ECO Meter, is it more than a vac gage? It seems to have more than one input?

 

If I'm highway cruising, the eco meter is in the middle unless I go past 70mph, like 76 or 80 then it goes to the right. I never noticed it go to the leftmost unless I am actually braking to a stop then it goes back to the middle.(confused)

 

Ken, are you talking about the upper-left gauge that you try to keep centered? Yes, the harder you press the brake pedal, the further to the left it swings (more heat dissipated in the brakes), the harder on the accel, the further right it swings. Never tried pressing both hard at once...

This gauge does not use vacuum, it is driven by the hybrid controller, which uses a host of information to move the needle.

 

coasting downhill doesnt make the needle move to the left(engine braking) but using the brakes does?-seems like counter-intuitive.

 

fj is right about the needle inputs. Basically moving the needle to the right at all on accel means you're losing efficiency; seems proportional to accel pedal input. But you want the needle to move to the left under braking to a certain point. Coast down doesn't regen much, so the needle isn't going to move much. You don't get max regen until the needle is about halfway through the green dashed portion. You're getting some friction braking at that point because it's blended braking, but it sets a good practical ideal limit for timing your stops. Anything past that is largely friction and you're throwing away regen efficiency.

 

Well, no. The needle straight up is most-efficient. Any deflection to the left or right is less-efficient. The more it deflects, the more fuel you are wasting, either slowing or going.
There is a practical limit to the deceleration side of things, as that is much more of a safety issue, but if you notice the needle as you are slowing for a light or stop sign when you are alone on the road (not having to worry about others for a moment), you will see that it takes very little brake effort to come out of the green-zone and also that we tend to brake harder near the stopping point. Keeping it steady over a long period, would allow for more regen than coasting followed by a hard stop, which is what I beleive KC was trying to say. Steady, light braking with good planning is best. Not looking at the little gauge on the dashboard while bringing your 5,000lb rig to a stop is even better...

 

If the engine regen braking is taking place, you are reclaiming energy, not spending it. Even light brake pedal pressure to slow the vehicle can be done and keep the ECO needle near the center without costing you. But like fjungman has said, any deflection further left than the thick center area of the green will cost energy, not recover it. Keeping it centered will gain the best mpg's. Speaking of MPG's...I just had my best tank 26Jan10...I got 20.2 mpg doing the math and 20.0 mpg average on the DIC...I thought I had cleared the average mileage already on the DIC! Because it goes back to what the EPA standard for the trucks is 20/20. My best tank!

 

Great discussion all thanks for the helpful information, the fact that the ECO meter is tied to the Hybrid controller is great.

 

Interesting this topic comes up. I was reading some posts last week regarding the effect braking has on the eco meter heading left and was surprised. I never noticed it went left! So, I have focused on braking lighter, rolling to stops (pissing people off) and keeping the eco meter in the middle. As a result I am at 23mpg in mixed use driving vs the normal 21mpg I get when braking in a less conscious manner. Thanks to everyone for their sharing their experience on this site it has help me greatly!

 

Good work!
On the "pissing people off" thing. I totally understand both sides. My opinion is that if they have no where to go, then you are just helping their MPG. Now, if you are keeping them from tripping the left turn signal, then they have good reason to be PO'd. Just be conscientious of people behind you and what they are trying to do. Make a car sit at a light for an extra couple of minutes because you kept him from the left turn lane, and you have wasted what was saved on the coast-down AND PO'd someone.
I brake late if there is someone behind me and an empty left turn lane. If the arrow is red and there is already someone waiting, then I do max-regen. They'll get there...
Did that make sense?