Also you should have the economy gauge in the dash area to help inform you of what your economy status is while driving.

Your best economy would be to try to keep the gauge in the middle area.

 

So far I haven't noticed any type of "modes" showing through the economy gauge.

On the Prius, you can clearly tell when you take your foot of the gas that you are generating some power with the simulated engine drag. You can tell how hard you need to press the gas pedal to then stop turning the MG's and just be in a pure coast.

On the other side - you can tell by the display how hard you can push the pedal and still be maintain the 100MPG range, and when you push through that area on the display, you see the MPG drop. So the display can be quite helpful over little distances showing you that you might be able to adjust your driving and get better mileage.

As far as I can tell, the economy gauge dips into the white zone as you press harder on the brake, but it's unclear to me that you are in pure re-gen mode when it is still in the green to the left of center. To the right of center, I'm not sure you really get anything out of the gauge except - yup I'm stomping on the gas.

 

when you press hard on the brake, you are wasting kenetic energy instead of charging the battery(regular brakes). hence the needle drops to the left. light foot on the brake activates the regenarative braking to charge the battery.
You can switch the DIC to Inst Econ. and watch tha mode you are driving in (V4,V8,or autostop)and your instant MPG. also if the RPM is at Autostop mode, this means you are runnign in EV mode only.

just my 2 cents

 

Thanks Guss -

On other hybrids, the gauges really help you tell when you have reached the point of maximum regeneration, but haven't yet engaged the mechanical brakes. That lets you try to stop by regen alone if you feather the brakes just right. It isn't clear to me at what point the mechanical brakes engage on the GM by looking at the economy gauge - do they start to engage when you hit the white, or are then partially engaged when the needle moves some distance to the left, but is still in the green? It's not very clear to me from the gauge exactly what is happening - and it would be nice to have a little better feedback.

Right now my main concern is trying to figure out of the hybrid battery pack is fully healthy. I have no warning lights to indicate otherwise, but I don't seem to have much of an EV mode only. I'm hoping others can give me some feedback on how well their EV mode only works. From a stop, if I push on the gas pedal at all, the instantaneous display shows I'm dropping right into V8 mode, and the MPG show 6-8, so there would appear to be very little assist from the battery pack.

From a stop, if I take my foot off the brake, the truck will start to roll on battery alone and I can get it up to maybe 20 MPH over the course of about 45 seconds while still on battery. I'm hoping you all will be able to tell me if that is normal, or if you can accelerate from a stop to 30 MPH on just EV mode - say in 10 or 15 seconds. If you can get up to 30 in a reasonable amount of time in just EV mode - then it would help confirm that something may not be right with my battery pack.

I wonder if pack health and SOC is anything the OnStar can read out?

 

Lake
You should be able to run on EV only up to 30 MPH on straight road up to 1-1.5 miles without having ICE kick in. as long as you are light footed on the gas.
what you can do, is go for along drive, 30 mins on highway, or you can drive on M mode, which will force the engine to stay running and charge the battery, then try to drive on EV mode only on flat road, and see how far you can go.

hope this helps

 

Thanks Guss -

That's quite helpful.

I don't seem to be able to really do anything in full EV mode, so I suspect that something isn't quite right. The truck did sit on a dealer lot for 8 months and didn't get run at all so I wasn't surprised when I took the test drive that the EV seemed a bit weak. But after driving it for a few hundred miles, this hasn't improved, so I'm suspecting there is an issue.

 

Lake,

Don't worry about your battery pack. It's fine. If it was low to start it got charged up quickly enough. SOC range is about 40-70%, and most of the time it's in the 50s.

Being this is still supposed to be a truck, I think GM didn't want to 'geek out' the displays too much. That said the simple eco needle is quite effective. At most speeds you are at the limit of regen braking at the left end of the top center green band. It's basically an accelerometer and the solid/dashed green band limit is around 0.15g decel. Regen exceptions: At high speeds you will clip regen quite quickly (and when pack is cold) before the needle gets to the edge. And at low speeds (coming to a stop) you can go into the dashed top green marks a little and still not be at the regen limit. So it's not 100% linear at all times, but it's a good guide. Like other hybrids, anticipate your stops, keep the needle centered as much as possible, and you will maximize economy. Also, I wouldn't worry too much about trying to stay in EV during accels. I think a pulse and glide technique works better; accel modestly up to your target speed and you will usually drop back into EV if you are below 28 mph. If not you will drop into V4 mode quickly, and still be doing fine. When I'm driving I try not to be that "hypermiling hybrid guy" that everyone gets mad at because he's holding up traffic trying to stay in EV. I get 22+ mpg composite regularly in my commutes.

You are in EVT Mode 1 up to about 28 mph. Input split mode like a Prius. You only get into fixed gear 1 briefly during hard accels from stop. Fixed gear 2 is the transition between Modes. Then you are in EVT Mode 2. When in Mode 2, during moderate accels you will go into fixed gear 3 (going up long steady inclines). Then when you are over 45 mph steady state the trans will go into fixed gear 4, which is a mechanical overdrive.

 

Thanks KC.

I had the dealer check on things, and as you say - all was good. I suspect that the pack was pretty depleted when I picked it up and just hadn't come up to charge yet.

After 50 miles, the lifetime MPG was at 14, at 250 miles is was at 15, at 500 it's now at 17.5 so it looks like the pack is contributing now. Mileage over the last fill as 19.5 - which is pretty good considering it included trips from 7000 feet to 0 and back - in 4WD and 1.5 feet of snow.

 

Lake
You can always reset the mpg by pressing the tick button for few seconds.
I do that after each fill up tank.

 

Thanks - yes.

I thought I would keep it on lifetime MPG by not resetting it, and just calculate the tank to tank MPG by hand - at least until I screw up and press the tick button at the wrong time.