define "rare" when it comes to green/purple bars

1 bar is 40%.

I go purple every day and green every day. It's not rare, it is just not the most common while driving. If every time you brake it goes green and every time you accelerate it goes purple, then you have a problem. Other than that, no worries.

The car can use battery only propulsion at any speed, even triple digit speeds. It is all based on power requested versus power available. The car makes the choices. You can force it by jabbing the pedal and things like that, but if you just drive it, then it works. In Pure EV mode, people have got the Prius almost to 80mph with no help from the engine on flat terrain.

 

The engine will be spinning but not necessarily producing power above 41 mph, in order to keep MG1 from over revving. The Prius engine is surprising in how little friction it makes in free wheeling mode.

 

No it's not rare at all, I also hit the green area almost every day (often several times per day).

As for it being bad for the battery - while minimizing the extremes of battery swings is probably good for battery longevity, even the full extent from zero bars up to 8 bars only corresponds to an actual charge range of about 40% to 80%. Certainly for a battery pack in good health there is no real problems with this.

As our battery packs age however they will lose some amp-hour capacity and some modules will diverge in capacity. This actually does increase the potential for large swings in battery SOC (state of charge) to push a weak module towards the danger zone of either undercharge or overcharge. I personally believe that an aging pack's longevity can be somewhat enhanced by diving to (where possible) minimize the very full charge (8 bars) and the very low charge (0 to 2 bar) states.

While I'd like to avoiding "maxing out" the battery to full 8 green as much as possible (especially with an aging battery), it's often difficult to do in practice. If you've got a lot of hills then there's often nothing you can do about it. The use of "B" mode on large descents does help to some extent though, it certainly delays "maxing out" the battery. BTW, I don't believe 7 green bars stresses the battery in any significant way, even on an old pack, so I never try to avoid that state.

Avoiding the very low states of charge (0 to 2 bars) is actually the easier of the two cases, and again (in my opinion) worthwhile doing if you've got an aging battery. In fact I believe that, except for extremes climbs like large mountain passes, we can all avoid the purple bar states by following one simple piece of advice. Let the engine warm (car in "P") for 40 to 60 seconds any time you're starting from cold. This greatly takes the strain off the battery in the first few minutes as the engine warms, and for me this has turned the the "purple bar state" from a daily occurrence to something that I now rarely see.

 

The stock Toyota EV mode (not readily available on North American GenII Prii) only allows EV speeds up to 35mph. The hardware under the hood however is capable of 80mph. It can be reached but requires a hack between the engine ECU and the Hybrid ECU. It is not for the faint of heart and not documented anywhere in an official capacity.

Stop overthinking it. It sounds like you are new to the Prius. Just let the car do what it does and forget about it. Battery life is prolonged by keeping it within the 40% to 80%, but guess what? That's exactly what Toyota does for you all by themselves. When it does get to 8 green bars (80%), the Prius will spin the engine without fuel as an air pump to bleed off excess charge for you. When it gets to 1 bar (40%) the Prius will spin the engine with fuel as a generator and recharge the pack even if sitting idle.

Toyota knows what they are doing, and the Prius can take care of itself. In many cases what people try to do to "help" is often detrimental.

All MPG you gain while in EV mode except for very rare (really rare) cases is artificial and short term. Your tank average will almost undoubtedly decrease. The car is not an electric vehicle, all power comes from gas. The point of the hybrid is for the car to determine what is most efficient for the current situation. If that is electric, then it will automatically be in EV mode without saying it. If it is a blend, more common, then it will do that. Run the engine in the efficient power band and use the electric engines to cope with the human input's jerky foot maneuvers and instant acceleration demands.

If you want to maximize your mpg's, then you can hypermile. It is an art and a hobby. It is not for everyone and the results are more more geek cred and saying "I did it" than anything else.

 

+1 2K1 said it plainly and concisely. Learn to hypermile and don't worry about the battery. The Prius will take care of that for you. Hypermiling is the real trick and is truly not for everyone. There are links in my signature file which will explain how to hypermile the Prius. The bottom line is if you will hypermile all of the time. Also note that there are different types and mode's of hypermiling. The best hypermiling results are achieved when you are travelling at speeds LESS than 42 MPH. So with all that said, study the link's in my signature for more information. It is all there in color with pictures and everything. Then go out and practice it. The record holder is in Japan. He averages well over 100 MPG for the entire tank. His maximum speed is also 16 MPH. Most folks who hypermile a Gen II can achieve 60 fairly easy if conditions are right. Gen III is a whole different ball game.

 

Without knowing your terrain,it is impossible to guess what is 'right'.

I can drive 150 miles and not gain 100 feet, Folks in SanFran or Seattle may not be able to drive 2 blocks without a 100 foot gain. So they will have MANY more Green and Pink events than I would.

 

In the Seattle area I spend about 33% of the time in the green zone. Rarely in the purple zone unless I am parked with the AC on.

 

Not top speed, average speed.

San Fransisco published a study they did on average speeds for commuters over the years. A couple years ago on the main interstates, the average speed was around 40mph. On the local city roads, is close to 20mph. So an average of 16mph just means more city essentially.

 

My car has about 55K. Model year 2008. It seems as if it has always spent more time in green than any other -- but I mostly drive hilly, backcountry roads, lots of them dirt. I see blue, sometimes.

Only once did I ever see purple and that was this past Labor Day weekend, which I spent much of my drive "parked" on Interstate 5, while trying to get home from Seattle....A normal 4.5 hour drive took about 7.5 hours that day.

 

I live in the mountains, I hit green & purple all the time, never seems to affect performance.

 

You will get the hang of it. It takes time and practice. After awhile you will probably do it naturally. Just a reminder: The best hypermiling results are achieved when you are travelling at speeds LESS than 42 MPH.

Best of luck to you and enjoy your Prius.

 

I would worry less about how you're doing during acceleration and more about the cruising and deceleration. I generally accelerate harder than most people would consider efficient, but in reality, it means you spend less time getting crappy mileage while accelerating. The money maker is pulse and glide when you're under 42MPH. Also, try coasting to stops instead of maintaining speed until the last possible moment. You don't need to coast to 0MPH without using the brakes, just start coasting a little before you would start braking. A lot of it comes down to practice and finding what works for your driving conditions and style.

 

Actually it means you usually drive on highways. When I got stuck in San Francisco, purple bars were quite common.

 

I was under the impression that "B" mode (engine braking) is not recommended with the Gen II Prius transmission.

 

Not recommended for normal driving? I'd agree with that, it generally lowers efficiency. However there are occasions when it can be useful, and large descents (those where you are likely to completely fill the battery) is one of those occasions. In my opinion this is even more the case when the traction battery is aging and losing some capacity.