Declining MPG; HSI Bar goes to "PWR" more often

Check your tire pressure, air filter and 12v battery to start.

 

i agree with the 12 volt. did you have the recall done?

 

no, but some have noticed less power after the recall, that's why i asked.

 

Do you always fuel up with the same brand of gas?

I have noticed fluctuations, in Fuelly, where my mpg had gone down significantly for several tankfulls, only to go back up.

I wondered if I just got a bad batch of gas, or the local refinery wasn't putting out what they should have quality wise during those times.

SCH-I535

 

The car is more likely to go into PWR when the hybrid battery SoC is low. How many bars do you see when this happens? If you're driving in EV mode a lot (intentionally, or just by pressing lightly on the gas pedal so the ICE is off), that can drain the battery quickly. Then it has to run the ICE harder next time it's on to fill the battery back up again. So it's possible that a change in your driving style is causing it...

 

You have the right idea, but you also need to add to the mix about trying to keep the SOC at least above the middle of the readout (60%) As everyone has stated, the bar will move over towards the power end easier when the SOC is low.

You mentioned EV use in parking lots. You will actually come out better if you limit your EV usage to strictly moving the car around in the driveway at home. If you leave it in normal mode or ECO, the car will automatically use EV mode if the SOC is 60% or more and the force on the go pedal is slight along with the speed being lower than the cutoff of 40 something. Watch the indicators on the dash when you are driving in normal mode in a parking lot and you will see what I mean.

The beauty of the Gen III over the Gen II is the redesigned HSI bar that are you talking about. It actually allows the user a easier method of controlling energy flow and usage thus getting the optimum MPG.



Use the ICE as needed to recharge the traction battery. Also use regen as much as possible for maximum regen back to the traction battery.

Best of luck to you!

 

what do you mean by " i'm in hybrid mode all the time "? there are 3 available modes: eco, normal and power. if you changed from eco to normal or power, or normal to power, the accelerator becomes more sensitive with the same amount of foot pressure and the his bar will move more quickly to the right. this will accelerate the car faster and possibly use more fuel if you don't comprehend what's happening.

 

From what I have learned so far, on the Gen III you will do better running in "normal" mode for around town and ECO mode when you are on the highway. "Normal" mode is when Power, ECO and EV is not lit up on the selector buttons.

Gen III Prius actually has four different selections to choose from. The selection you choose will modify how the go pedal works and also adjust the A/C some.

Remember this no free ride with the Prius. The power in the traction battery mainly comes from the ICE. Some of it comes from regen. You will actually do better if you hypermile using pulse and glide methods than you would straight driving or trying to drive in EV mode all of the time.

Read the link in my signature about how to hypermile. It is for Gen II, but the principle still works in Gen III. When gliding in a Gen III, the HSI indicator will show nothing or a small amount. Look closely at the pic I posted above. Note the area that is marked "Optimal Gliding Here". Learn about P&G and use when you can. You should see a increase in your overall MPG.

Here's a great video on hypermiling a Gen III Prius you can watch.

 

When I drive in city/suburban, I use the gas pedal as an on/off switch and keep the HSI at either yellow of green zone (as close to extremes as possible). The benefit is the best MPG and the least wear and tear on the HV battery.

I figured out very early on that forcing EV as much as possible resulted in bad MPG numbers and lots of battery cycling. Now, I do the opposite, force ICE as soon as I get in the car.

 

for the last few tanks I have been exclusively using ECO mode. and my MPG indicated has been around the 45 mark. (42-43 actual)

this current tank I am running in normal mode and halfway through i am holding at 49. but we have had warmer weather as well. and I am driving the car keeping an eye on the HSI gauge and staying out the PWR range and not doing anything else special. kinda keeping up with traffic ect.

After running inco mode for a few thousand miles, its hard to get used to the pedal sensitivity in normal mode.

 

I do agree that ECO seems to have the "response" that I am familiar with in comparison to the Gen II on the new Gen III.

At first I didn't see or feel the difference, but upon further driving in both normal and eco mode, I found that I prefer the eco mode also. Even if I don't hypermile using P&G I am seeing over 50 on the computer. Will know more after a few tanks of fuel. I believe if I go with the old standard of P&G which basically means using ice in mid to upper range without hitting close to power zone and then feather back to bottom of the HSI as the two of you are talking about and also as the video shows, that the MPG will be much better.

I do agree that the sensitivity is much greater in ECO mode than normal mode thus giving you better control over the go pedal.