Evo Mode - Any Point?

[monya]

For short journeys it saves fuel I suppose. But presumably it depletes Battery level. So on the next journey won't the engine cut in more often to help it recharge, therefore saving nothing in the long run?

[Seamaster73]

What's "Evo" mode?

[monya]

Sorry, meant Battery only mode

[RNS]

i use EV mode when driving around the local council estate you have to drive at low speed coz its narrow streets and lots of speed bumps anys so just seems like a good idea to me.

[Grumpy Cabbie]

EV is a bit of a gimmick but can be useful for moving the car short distances without wasting fuel - ie reversing out of garage or swapping cars around on the drive. It can also be handy for short bursts in traffic where you know specifically don't want the engine to fire up - short distances between traffic lights etc.

I'd be wary of using EV too much as it really eats the Battery charge level and the charge will be replaced automatically by the car - and the way it does this is to run the engine more burning more fuel.

[THX]

I think EV mode is essential and can be used to an advantage saving fuel; examples:

-the car will always start the engine in the morning irrelevant of the Battery charge level to get it at an optimal running temp and in winter this may stay on longer, so when coming home in the evening I use the EV mode as the morning warm up then also goes towards charging the Battery i.e. No point parking the car with full charge!

-when you want to stay in Battery mode with speeds below 25mph when accelerating from a stop or traffic light; EV button will force it to stay in battery mode but if you leave it for the car to decide then any heavy acceleration will kick in the engine even as low as 10mph (this with Eco mode helps in moving traffic where you don't want idiots cutting in because you are not keeping up with the acceleration of the car in front)...

-This is also great to build up fast momentum but still remaining in battery mode before a downhill which charges any access battery you use up to get to the apex of the hill...

Situations like these are impossible for the car's computer to predict, so I take this button as human intelligence option helping the otherwise artificial intelligence driven battery management...

[Jan&tone]

It's interesting to see how people use their EV mode. In my Gen2, I used to use it in heavy traffic until the Battery ran down and then waited for the engine to charge it up (or a downhill stretch) but the Gen3, doesn't seem to charge so much when coasting or downhill. I've not yet done the miles in the Gen 3 to work out the best way for me to use EV yet, but I will !!

[Grumpy Cabbie]

I think EV mode is essential and can be used to an advantage saving fuel; examples:

-the car will always start the engine in the morning irrelevant of the battery charge level to get it at an optimal running temp and in winter this may stay on longer, so when coming home in the evening I use the EV mode as the morning warm up then also goes towards charging the battery i.e. No point parking the car with full charge!

-when you want to stay in battery mode with speeds below 25mph when accelerating from a stop or traffic light; EV button will force it to stay in battery mode but if you leave it for the car to decide then any heavy acceleration will kick in the engine even as low as 10mph (this with Eco mode helps in moving traffic where you don't want idiots cutting in because you are not keeping up with the acceleration of the car in front)...

-This is also great to build up fast momentum but still remaining in battery mode before a downhill which charges any access battery you use up to get to the apex of the hill...

Situations like these are impossible for the car's computer to predict, so I take this button as human intelligence option helping the otherwise artificial intelligence driven battery management...

Its interesting to see how other people use the car.

I would disagree with you regarding using EV before morning as when on the warm up cycle the next morning the car will use more from the HV Battery than normal to power the car whilst it warms the engine up and reducing emissions. That is why if you park with a full Battery the night before, the car will 'eat' away at the charge when you first run it the next morning.

Check out the US Prius forum which gives a break down of the various warm up stages of the Prius. On one of the early stages it uses the electric motor only to power the car (unless you head into the red power band) with the engine running only to power the generator.

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV Battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

[fuel miser]

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

I really can't see that this would do any harm, otherwise they wouldn't give us an EV switch. Remember that, to maximise the lifespan of the Battery, it only utilises a very narrow portion (20%) of the Battery capacity. It can never charge more than 60% or discharge less than 40%.

[timberwolf]

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

I really can't see that this would do any harm, otherwise they wouldn't give us an EV switch. Remember that, to maximise the lifespan of the Battery, it only utilises a very narrow portion (20%) of the Battery capacity. It can never charge more than 60% or discharge less than 40%.

IIRC the HV Battery has a State of Charge (SOC) range between 40% to 80% (+/- 1 or 2%), but yes as I understand it the the narrow usage SOC range is to prolong the life of the battery. I don't think it answers the question of whether we as a driver are smarter than Toyota's complex battery management technology?

[fuel miser]

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

I really can't see that this would do any harm, otherwise they wouldn't give us an EV switch. Remember that, to maximise the lifespan of the Battery, it only utilises a very narrow portion (20%) of the Battery capacity. It can never charge more than 60% or discharge less than 40%.

IIRC the HV Battery has a State of Charge (SOC) range between 40% to 80% (+/- 1 or 2%), but yes as I understand it the the narrow usage SOC range is to prolong the life of the battery. I don't think it answers the question of whether we as a driver are smarter than Toyota's complex battery management technology?

I knew I'd read it somewhere, but it may of course be wrong.......

In 1994, Toyota executive Takeshi Uchiyamada was given the task of creating a new car that would be both fuel efficient and environmentally friendly. After reviewing over 100 hybrid designs, the engineering team settled on a hybrid engine design based on a 1974 TRW patent, but many technical and engineering problems had to be solved within the three years that the team was given to bring the car to the Japanese market, a goal they barely achieved as the first Prius went on sale in December 1997. A main problem was the longevity of the battery, which needed to last between 7 and 10 years. The solution the engineers came up with was to keep the battery pack between 60% and 40% charged, proving to be the "sweet spot" for extending the battery life to roughly that of the other car components.

[THX]

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

I really can't see that this would do any harm, otherwise they wouldn't give us an EV switch. Remember that, to maximise the lifespan of the Battery, it only utilises a very narrow portion (20%) of the Battery capacity. It can never charge more than 60% or discharge less than 40%.

Irrelevant of the level of the Battery charge left in the morning, the engine will kick in; the engine run time is very much outside temperature dependant NOT the level of battery charge left.

I don't usually manage to reach as low as 2 bars by the time I park but being in EV mode helps remain on battery for a small part which is uphill; good to see US forums have some theories but I cannot see Toyota designing the charge circle so they expect you to have a good charge before parking as it would mean you would have to heavy accelerate into your drive way to gain some charge before parking...

[timberwolf]

I personally would not be too keen using EV too often as I am not convinced regular deep cycling of the HV battery (from full to 2 bars in a couple minutes) can be no good for it, esp in the long term.

I really can't see that this would do any harm, otherwise they wouldn't give us an EV switch. Remember that, to maximise the lifespan of the Battery, it only utilises a very narrow portion (20%) of the Battery capacity. It can never charge more than 60% or discharge less than 40%.

IIRC the HV Battery has a State of Charge (SOC) range between 40% to 80% (+/- 1 or 2%), but yes as I understand it the the narrow usage SOC range is to prolong the life of the battery. I don't think it answers the question of whether we as a driver are smarter than Toyota's complex battery management technology?

I knew I'd read it somewhere, but it may of course be wrong.......

In 1994, Toyota executive Takeshi Uchiyamada was given the task of creating a new car that would be both fuel efficient and environmentally friendly. After reviewing over 100 hybrid designs, the engineering team settled on a hybrid engine design based on a 1974 TRW patent, but many technical and engineering problems had to be solved within the three years that the team was given to bring the car to the Japanese market, a goal they barely achieved as the first Prius went on sale in December 1997. A main problem was the longevity of the battery, which needed to last between 7 and 10 years. The solution the engineers came up with was to keep the battery pack between 60% and 40% charged, proving to be the "sweet spot" for extending the battery life to roughly that of the other car components.

Interesting, that may have been the case for the Japanese version when the Prius was first introduced.

The values I recall come from various source, but the PHEV hackers seem to have come up with the following for the Gen 2 Prius. Toyota_Prius_Battery_Specs#Battery_Bars_and_SOC_.25

[DrCez]

Situations like these are impossible for the car's computer to predict, so I take this button as human intelligence option helping the otherwise artificial intelligence driven battery management...

Perhaps the "EVO" button (I assume it is called that on the Auris: it's "EV" on the Prius) should be renamed the "EGO" button because it's a button to be used when you think you know better than the car's computer :)

I would expect that a majority of the time using energy from the Battery is less efficient than using direct from the internal combustion engine (ICE) because of the losses in generating, storing and then re-using the charge in the Battery. My philosophy is similar to THX's, the idea being that in some situations you know in advance that the car will be able to recharge the Battery in a few minutes - as you approach the brow of a hill, for example (I wonder if the next generation of hybrids could start using the satnav to make these sorts of predictions?) - so arguably it is more economical to force the car to use more battery charge. I used to do this sort of thing quite a lot in town driving but the more I think about it the more I think it is better to let the engine run due to the efficiency considerations already mentioned.

Personally I find it more practical to keep the HSI to the left of the centre line rather than use the EV button: often I find I'm in a situation where EV mode is unavailable (speed, charge, something else) but I can still drive with the ICE off (maybe I'm not skillful enough to use EV properly!). Pretty much the only time I use my EV button is to repark the car. I really like the fact that if you press EV within a few seconds of powering on the engine will stay off even if it is cold, and IMO this is the most beneficial application of the button.

I would disagree with you regarding using EV before morning as when on the warm up cycle the next morning the car will use more from the HV battery than normal to power the car whilst it warms the engine up and reducing emissions. That is why if you park with a full battery the night before, the car will 'eat' away at the charge when you first run it the next morning.

I must admit I like running on electric only as I approach home because it improves my mpg stats for that individual journey and I had reasoned, like THX, that the car would be running from cold on the next journey so might as well recharge the battery while it warms the ICE up. I'd like some stats to convince myself but even on the same commute it is difficult to factor out the effect of daily changes in traffic and weather conditions.

Arguably an exception would be when it is so cold that you need the cabin heater on (and the car therefore needs to run the engine to provide hot air rather than just warm itself up), which is happening around now for me in the mornings.