Any ideas what the rear air con does to fuel consumption?

 

1 mpg or less.

 

Not sure, but I keep it turned off unless someone is riding in the back seat. My wife complains that it blow cold air on her neck. Not sure if that is true but that is what she claims.

Dennis

 

I believe it's just a take-off from the main A/C (there's only one compressor) so it should have no effect on mpg.

 

no effect would be correct ...except more lovely cool air !

 

No effect as stated due to the AC running on the one and only compressor.

Is this really a concern?? Couple of bucks a month?

 

Are we talking about a dual zone or a 4-zone climate control system. The latter had a separate AC system behind the rear seat so as far as I know it does not run off of the same compressor.

Still I think the MPG effect would be marginal regardless of what system.

 

It's a seperate CONDENSER, but compressors require a motorized input to pump to the condenser, hence the one under the hood running the pump via the serpentine belt.

 

Good info, but I think you're referring to the evaporator, not the condenser. The condenser is on the high side of the system in front of the radiator. The evaporator is on the low side (cool side) of the system usually in the duct work.

 

I run mine during the hot weather and summer months with no difference in MPG, far as blowing on the wife's neck the vent is adjustable to prevent that.

 

Tee I tried that with no success. After 46 years you just learn to live with the little things.

Dennis

 

My mistake

 

I just bought the car so I don't know? Most of the time there's just one person in the car, so I was wondering if it's worth worrying about turning the rear AC off.

 

Leave the rear A/C on at all times. Helps cool the car down quicker and maintains a more uniform temperature in the car. Also, the rear has a UV light that purifies the air, which is a very important feature. If all this is too much, just sit back, let it do it's thing, and enjoy it.

 

I checked Lexus Tech Docs, and it says:

Heater power: 210W power consumption
Front aircon: 300W power consumption
Rear aircon: 60W power consumption

So the rear aircon consumes very little power

•In order to further improve the comfort of all occupants, on models with the multi-zone (4-zone) automatic climate control, the air outlet is respectively provided at the rear air conditioning with cool box and air purifier function, roof side rail and roof.

•The air outlet is placed at the lower part of both center pillars are used.

•The non-sliding film damper is provided with the air mix control damper inside the front air conditioning unit, and thus the air volume can be independently adjusted on both the right and left sides of the air outlet.

•The Positive Temperature Coefficient (PTC) heater system is provided as option. This system contains a PTC heater that heats the air that has passed through the heater core to ensure proper heater performance.

•Neural network control is used so passengers can accurately control the air conditioning for maximum comfort.

•FACE mode for the rear seat is installed to blow warm air and ensure excellent heating performance.

•A micro dust and pollen filter, which removes pollen, is used as the clean air filter.

•Micro dust pollen filter mode control is used to remove pollen in the area around the upper part of the bodies of the driver and front passenger.

•The blower control has 7 levels for precise control.

•Automatic recirculation control is used to help prevent harmful elements such as CO, HC and NOx from entering the cabin.

•A [nanoe] generator is provided under the multi-media module receiver assembly to improve the air quality and comfort in the cabin.