Does Mk4 Jazz ever drive in EV mode with climate control on?

[peteo48]

Just watched a You Tube video of a chap in the Czech Republic test driving a Cross Star in Prague. I know we've covered this before but the tester said that you need to turn the climate control off if you want the car to run in EV mode. If the climate control is on the petrol engine is on (although not necessarily powering the car directly).

Is this the case? I'm someone who likes to set Climate Control up to my requirements and then leave it to do its job but if this means the petrol engine is always ticking over I don't think I would be tempted by the Mk4.

[Kremmen]

Good point, I have my CC on all the time, 21C in winter and 19C in summer.

[IanG]

If switching on the climate control causes the engine to operate at all times, does this also occur when the AC part doesn’t kick in, eg if temp is set to 22 degrees and the ambient temp is below this, so the heater is in operation rather than AC cooler?
If climate control switched on prevents EV mode, does the ‘Econ’ switch allow EV mode to function when the climate control switched on?

[Expatman]

Don’t think the two are linked, ICE has to be running to provide heat to the cabin because there is no “electric” heating system. Cooling uses power to drive the compressor and, I assume, draws power from the EV battery. If that’s right then ICE will only fire up when the EV battery is discharged to the point the ICE is needed to charge it and power the drive motor.
However, if the compressor gets it’s power direct from the charge motor and not from the battery then the ICE will have to run to power it. In which case MPG in the summer is going to nosedive if you use the A/C. Fundamental question - anyone technically up on this to provide categorical answer?

[John Ratsey]

It all depends on the temperature. The aircon is electrically powered and the vehicle is happy to run in EV mode with the aircon running although this must reduce the operating time before the engine cuts in. However, if heat is needed then that has to come from the engine which can have a noticeable impact on efficiency in cold weather.

Pressing the Econ button increases the allowable difference between target and actual cabin temperature and thus reduces the amount of time the engine / aircon operate to provide heating / cooling.

[Bristol_Crosstar]

I used to have the climate control on all the time on my old Mk2 petrol car. On the Crosstar the more electrical gadgets you have switched on, the less time you spend in EV mode whether it's aircon, lights etc. but you can be in EV mode with climate on if it's not got to work too hard. Now the weather's warmer the windows are less likely to steam up so I switch climate off if it's not required. You can leave it on all the time but it will increase your fuel consumption (as it does on a petrol car, it's just less noticeable). In either case you'll be using a lot less fuel than in a petrol car.

[peteo48]

Thanks for the replies which all make sound sense. I can see that, if heat is required, the engine will need to be on. One thing that has occurred to me is observing Toyota Hybrids. The new range claim that they can (as opposed to will) run for up to 4 miles in pure EV mode and can reach 70 mph.

There are a lot of Toyotas near me as the main dealer is only 5 minutes away. The Hybrids do seem to operate in EV mode automatically when moving from a standing start. Have they all got the climate control off? Is it possible to use residual heat rather than turning the engine on. My feeling is that, if I bought a Mk4 Jazz, the engine would rarely be off except, say, when the ambient temperature is higher than the setting chosen.

Having said that, I guess the petrol engine would only be idling so I may be overthinking this!

[ColinB]

Having said that, I guess the petrol engine would only be idling so I may be overthinking this!

Wouldn't the ICE, if running, always be running at it's most efficient speed? The notion of "idling" (ie engine running under no-load conditions) might not apply to a hybrid like the Jazz, because if there's no load from the generator, heating demand or direct drive then the engine won't be running?

[Bristol_Crosstar]

Thanks for the replies which all make sound sense. I can see that, if heat is required, the engine will need to be on. One thing that has occurred to me is observing Toyota Hybrids. The new range claim that they can (as opposed to will) run for up to 4 miles in pure EV mode and can reach 70 mph.

There are a lot of Toyotas near me as the main dealer is only 5 minutes away. The Hybrids do seem to operate in EV mode automatically when moving from a standing start. Have they all got the climate control off? Is it possible to use residual heat rather than turning the engine on. My feeling is that, if I bought a Mk4 Jazz, the engine would rarely be off except, say, when the ambient temperature is higher than the setting chosen.

Having said that, I guess the petrol engine would only be idling so I may be overthinking this!

If you just want heat then the heated seats are an alternative to using climate

[Downsizer]

My feeling is that, if I bought a Mk4 Jazz, the engine would rarely be off except, say, when the ambient temperature is higher than the setting chosen.

Sunlight warms the car well above the ambient air temperature.  I needed air-conditioning in my Mk3 in yesterday's sunshine although the air temperature was only around 14 C.  I rarely need heat in East Anglia between April and September, but I suppose it depends on where you live.

[Expatman]

My feeling is that, if I bought a Mk4 Jazz, the engine would rarely be off except, say, when the ambient temperature is higher than the setting chosen.

Sunlight warms the car well above the ambient air temperature.  I needed air-conditioning in my Mk3 in yesterday's sunshine although the air temperature was only around 14 C.  I rarely need heat in East Anglia between April and September, but I suppose it depends on where you live.

It is the air conditioning that is really the question here, is it (compressor) driven solely by the generator/engine or can it be driven by the EV battery? If only driven by the engine/generator then in the summer the engine will be running most of the time to cool the cabin. I would think that the compressor is driven by the EV battery then the engine will only fire up when the battery is exhausted by the electric motor driving the wheels and/or the compressor. Really need a definitive answer from a Honda technical expert?

[Bristol_Crosstar]

My feeling is that, if I bought a Mk4 Jazz, the engine would rarely be off except, say, when the ambient temperature is higher than the setting chosen.

Sunlight warms the car well above the ambient air temperature.  I needed air-conditioning in my Mk3 in yesterday's sunshine although the air temperature was only around 14 C.  I rarely need heat in East Anglia between April and September, but I suppose it depends on where you live.

It is the air conditioning that is really the question here, is it (compressor) driven solely by the generator/engine or can it be driven by the EV battery? If only driven by the engine/generator then in the summer the engine will be running most of the time to cool the cabin. I would think that the compressor is driven by the EV battery then the engine will only fire up when the battery is exhausted by the electric motor driving the wheels and/or the compressor. Really need a definitive answer from a Honda technical expert?

The Aircon is driven by one of the batteries, the engine is used to charge up the EV battery when the power level is low. The 12v battery is charged from the EV battery, not the engine.

[jazzaro]

Just watched a You Tube video of a chap in the Czech Republic test driving a Cross Star in Prague. I know we've covered this before but the tester said that you need to turn the climate control off if you want the car to run in EV mode. If the climate control is on the petrol engine is on (although not necessarily powering the car directly).

Is this the case? I'm someone who likes to set Climate Control up to my requirements and then leave it to do its job but if this means the petrol engine is always ticking over I don't think I would be tempted by the Mk4.

The aim of an hybrid powertrain like Jazz or Toyotas isn't to run the most of the time in EV: i-MMD and HSD are used to keep the petrol engine running in the best conditions or to stay off, that's why the power battery is very small. Who wants to drive in EV mode should buy an EV or a plug-in hybrid.

[peteo48]

Fair point jazzaro.

[richardfrost]

The aim of an hybrid powertrain like Jazz or Toyotas isn't to run the most of the time in EV: i-MMD and HSD are used to keep the petrol engine running in the best conditions or to stay off, tha's why the power battery is very small. Who wants to drive in EV mode should buy an EV or a plug-in hybrid.

Exactly.