Climate On Auto - Ac Always On?

[bigmick777]

My first lexus! Just wondering, on Auto on the climate is AC always on regardless?

Missus car has auto climate (renault) only puts AC on when it cant cool the air using outside air, hence, in winter it doesnt use it.

Notice with mine that as soon as you click auto, AC goes on. Click AC off and it goes to manual.

Looking at other options of trying to improve MPG but wondered about this!!!

[LexusForever]

my AC is never off. several dealers (not just lexus or toyota) have told me that modern systems like to be on all the time, and to be honest, i haven't noticed any difference in consumption (gettign anywhere between 33 and 39mpg depending on journey). my advice is just let it do its thing. i have even started leaving the AC on in my other car which is an Aygo.

[Ro1]

I leave the AC on all the time too. I notice that the AC sometimes switches off if the outside temperature drops very low. Has anyone else noticed this?

[Whoever]

If you go to the climate screen, you can turn AC off, but if AUTO is still illuminated, you will just have climate control. I usually have this set up, except for sweltering or humid days, and the occasional damp day. Even in this setting, once the car has reached the required temperature, it will start to cool the cabin down. On a long trip, you can feel this heating and warming, but overall the temperature change is minimal.

When I feel cooler air on my face I know the system has reached the optimim temperature, and I turn everything off. It makes sense, to me at least, the let the cabin cool naturally, rather than getting into the warm/cool situation.

If you have MM, try leaving the Climate screen on and you will see the fan speed and air direction change as the cabin warms up.

I wouldn't know if my method improves mpg, but my view is that climate control is highly desirable and aircon is essential several times a year.

Opening the windows just makes the journey noisy and the interior dirty!

[Parthiban]

That seems odd, should be able to switch the AC off but still have it on auto - is the system set to fresh air or recirculate?

But as above, it's best to leave the AC on if you can, makes the air more pleasant, keeps the windows free of mist, and keeps the system well lubricated to prevent more expensive problems in the future.

[bigmick777]

That seems odd, should be able to switch the AC off but still have it on auto - is the system set to fresh air or recirculate?

The system is set to fresh air on mine. Clicking off AC takes auto off. Not tried it on recirculate.

Happy to leave it on all the time was curious. Not tested any MPG gains from having it off but me trying to claw back MPG on this diesel is another issue!

[Parthiban]

That does sound weird - could it be something to do with the fact it's a diesel?

I haven't personally tried switching the AC off in a mk2 IS but I've never come across a car that does that before, I'll have to try it in the Prius and see if it does the same as the climate system is the same I think.

[vektor12]

Mine, although on Auto, switches off the A/C from time to time, though I haven't (yet) discovered any pattern (but for sure in winter time).

[vektor12]

Mine, although on Auto, switches off the A/C from time to time, though I haven't (yet) discovered any pattern (but for sure in winter time).

[vektor12]

Mine, although on Auto, switches off the A/C from time to time, though I haven't (yet) discovered any pattern (but for sure in winter time).

[vektor12]

Mine, although on Auto, switches off the A/C from time to time, though I haven't (yet) discovered any pattern (but for sure in winter time).

[Dave250]

I just want to be able to set the temperature and let the car do the rest (i.e. warm up air when necessary, cool air when necessary, increase fan to get to the required temperature quickly etc). I thought this is what Climate Control did but I've not been able to achieve this after 20 months and 40k miles of ownership!

[LexusForever]

Dave250, mine does exactly that if i leave it on auto, with the AC on. all i ever do is set the temperature i want and it does the rest, and if i leave the screen on climate, i can see it changing the vent position and fan speed. i also leave the recirculation setting on auto. the only time i change the setting is to defrost the windscreen by pressing the front defrost button, and then it goes back to auto when i turn it off.

are you sure you have the auto setting on?