Eco Mode

[Notamech]

So ive been experimenting with using eco mode on the car to make fuel go further. I noticed that the engine takes much longer to get to full operating tempreature. I do a 10 mile trip almost every day. During the 10 mile drive the engine tempreature gauge is mostly at around 1/4th way up vs a tad under 1/2 way up like in normal mode. And if I get stuck in stop and go traffic then sometimes the tempreature gauge goes almost all the way back to the bottom when stopped. In general depending on traffic if I am in eco mode typically the car gets to full operating temperature almost at the end of the 10 mile journey or not at all. But in normal mode it gets to full operating temperature pretty fast (around 2-3 miles) and stays there irrespective of traffic. 

Has anyone else noticed this? If so does anyone know why in eco mode the engine would run cooler for longer. Surely the faster it warms up fully the more efficient the engine will be? 

[IS300FSPORT]

If you use the heating or heated seats you will notice the engine will come on & stay on regularly more to preserve and recharge the Battery recharging slowly using the engines power & to give you heat from the engine. The reason its switching the engine off when in Eco is because the 1st opportunity it sees based on specific parameters being met its switching to EV (Electric) as soon as it can its reserving power/fuel when idle same as any other car equipped with stop start tech. 

Petrol engines will generally warm up well within 2-3 miles, depending on how long your sat idle & how cold it is for the temp to drop is quite normal. The petrol engine will automatically kick in as & when it needs to. 

[Notamech]

7 hours ago, IS300FSPORT said:

If you use the heating or heated seats you will notice the engine will come on & stay on regularly more to preserve and recharge the battery recharging slowly using the engines power & to give you heat from the engine. The reason its switching the engine off when in Eco is because the 1st opportunity it sees based on specific parameters being met its switching to EV (Electric) as soon as it can its reserving power/fuel when idle same as any other car equipped with stop start tech. 

Petrol engines will generally warm up well within 2-3 miles, depending on how long your sat idle & how cold it is for the temp to drop is quite normal. The petrol engine will automatically kick in as & when it needs to. 

Got it. So sounds its normal. From what you've said and reading on some prius forums it sounds like the heat thresholds are lower when in eco mode for the engine to shut off and switch to electric to maximise economy. Hence it doesn't really wait to get to full operating temperature to begin switching. 

 

However? Is this a false economy though? Because not operating at full ideal tempreature probably means more wear on the engine components and hence not great in the long run? 

[IS300FSPORT]

1 hour ago, Notamech said:

However? Is this a false economy though? Because not operating at full ideal tempreature probably means more wear on the engine components and hence not great in the long run? 

It is down to how deep your pockets are of course.

In terms of economy most cars will see poor MPG in traffic conditions simply because of continuous stop & go. The key is maintenance. 

If your genuinley worried about long term reliability rest assured you have bought the right car. You Just need to look at Taxis in service Prius etc. Lexus/Toyota will do mega miles providing you maintain it.

Without getting all scientific as long as your changing the engine oil & filter to the manufacturer recommendation under 'Severe' conditions If im not mistaken it is 5000 miles rather than 10,000 you will have no problem. Engine oil degrades with continuos warmup cycles. Keep the oil changed regularly if your doing strictly low miles or short runs you will not or should not have a problem I have stuck by this rule & havent had an engine cause me any issues yet.

When I was in the trade I have seen examples where owners are more likely to corrode the brake discs, & exhaust systems because of extremly short runs because they dont get upto temperature regularly before the engine gives you trouble. Not to mention carbon build up but this engine is not known to suffer from these issues as yet. Get it upto temperature & give it a regular Italian tune up keeps it running beautifully. 

[Mr_Groundhog]

26 minutes ago, IS300FSPORT said:

 give it a regular Italian tune up keeps it running beautifully. 

You mean revving it up to the red zone for a few seconds?

I try to do it every now and then but the car stubbornly goes back to low revs quickly by itself. 😅

[Notamech]

1 hour ago, IS300FSPORT said:

It is down to how deep your pockets are of course.

In terms of economy most cars will see poor MPG in traffic conditions simply because of continuous stop & go. The key is maintenance. 

If your genuinley worried about long term reliability rest assured you have bought the right car. You Just need to look at Taxis in service Prius etc. Lexus/Toyota will do mega miles providing you maintain it.

Without getting all scientific as long as your changing the engine oil & filter to the manufacturer recommendation under 'Severe' conditions If im not mistaken it is 5000 miles rather than 10,000 you will have no problem. Engine oil degrades with continuos warmup cycles. Keep the oil changed regularly if your doing strictly low miles or short runs you will not or should not have a problem I have stuck by this rule & havent had an engine cause me any issues yet.

When I was in the trade I have seen examples where owners are more likely to corrode the brake discs, & exhaust systems because of extremly short runs because they dont get upto temperature regularly before the engine gives you trouble. Not to mention carbon build up but this engine is not known to suffer from these issues as yet. Get it upto temperature & give it a regular Italian tune up keeps it running beautifully. 

All makes sense. I agree, these days the drivetrain is likely to outlast the rest of the car anyway. My neighbour has a 2008 gen 2 prius that is extremely poorly maintained but is his daily driver and works fine. Like the thing  literally has different coloured body panels (probably from a salvage yard) but keeps going so must be mechanically sound. 

I do around 5k miles a year and am a bit obcessive about the car so hopefully servicing once a year should be fine and it will be trouble free motoring. 

 

Also another workaround I figured that works for my use case is to get the engine fully warm in normal mode then when its at temperature switch it to eco. This way the temp remains constant and doesn't keep dropping. Also since the engine is warmed up faster its better for heating the interior as well. 

[IS300FSPORT]

1 hour ago, Mr_Groundhog said:

You mean revving it up to the red zone for a few seconds?

I try to do it every now and then but the car stubbornly goes back to low revs quickly by itself. 😅

When safe to do so on a roll obiding by the law  (cough) get to around get to about 50-60mph knock it into Sport, shift down to S3 & give it acceleration upto a certain speed. Only the Lexus Senseis will know what is going on mechanically the CVT box I believe only has the one gear but the way it takes off is quite impressive it does rev out or appear to rev out the evidence on the rear bumper on a white car shows its cleared its lungs out small particles of soot if you look hard enough. I usually do this once a month before im about to fuel up so not feeling too guilty about MPG. 

P.S im all for eco driving but this motor has best of both worlds.

[wharfhouse]

As I understand it, in Eco mode the heating and air con is reduced in capacity (for want of a better way to express it as it will still reach the temperature set on the climate control just not as quickly) to save on energy too - in Normal (or Sport) mode it will heat or cool more quickly and maintain temperature better (at the expense of some additional fuel consumption either running the ICE for heat or to recharge the HV Battery for the additional air con load). Using the S-flow button on the dash to stop hot or cold air to the rear seats when not carrying rear seat passengers can also help with the heating / cooling of front seat occupants and save some fuel. 

[Spacewagon52]

Very interesting thread - thanks. I presume all this would apply to the NX - except I do not think it has the S-Flow button?

[Mr_Groundhog]

On 3/16/2023 at 11:32 AM, wharfhouse said:

As I understand it, in Eco mode the heating and air con is reduced in capacity (for want of a better way to express it as it will still reach the temperature set on the climate control just not as quickly) to save on energy too - in Normal (or Sport) mode it will heat or cool more quickly and maintain temperature better (at the expense of some additional fuel consumption either running the ICE for heat or to recharge the HV battery for the additional air con load). Using the S-flow button on the dash to stop hot or cold air to the rear seats when not carrying rear seat passengers can also help with the heating / cooling of front seat occupants and save some fuel. 

Which is the S-flow button? I don't think I have it... 🧐

[IS300FSPORT]

44 minutes ago, Mr_Groundhog said:

Which is the S-flow button? I don't think I have it... 🧐

 

[Notamech]

50 minutes ago, IS300FSPORT said:

 

You know yesterday after reading this post i had the same question, went looking for the s flow button was the first time ever that i noticed that button. Thats what I appreciate about this forum the most. Its probably the only car forum where I have actually learnt and discovered new things. 

[Mr_Groundhog]

2 hours ago, IS300FSPORT said:

 

Thank you! .....I had not paid any attention to that button either! I'm clearly blind!