A/C Engaged With Defrost

[Lonestar]

Originally Posted by Reddog99

I believe that recirc is unavailable when using defrost, isn't it?

Yes, it is! I was referring to using the a/c with the recirc feature, the OP was concerned about MPG and performance. Recirculating the already dehumidified air with the a/c on----->less compressor time------>less drain on mpg and performance.

Sorry, I wasn't clear.

[FORDSVTPARTS]

Originally Posted by Lonestar

Yes, it is! I was referring to using the a/c with the recirc feature, the OP was concerned about MPG and performance. Recirculating the already dehumidified air with the a/c on----->less compressor time------>less drain on mpg and performance.

Sorry, I wasn't clear.

Actually if you have manual A/C it'll run the compressor with the same frequency regardless of if it's on recircluate or not but it'll make the air much colder on recirc.

With a car that has ATC it will cycle the compressor only as required to keep the temperature at the preset temp but unless I'm mistaken the North American market Fiesta doesn't have ATC as an option.



.

[Scooby Doo]

FordSvtParts;

you always have good info

[f91]

Granted with the AC on, the defroster is more effective, but I think manufacturers want a way for customers to exercise their AC compressors frequently with actually "knowing" that they are turning the AC on. If the AC compressor just sits around for months not doing anything, it more susceptible to frozen bearings or other malfunctions. If the main objective was really that AC air is more effective, why wouldn't they just tell you and tell you to turn on the AC when defrosting?
When I'm driving in the winter, I turn off defrost as soon as I can because it really does rob mileage and power. AND, I stayed at a Holiday Inn the other night....