unclejosh

I have been seeing roughly 1 mpg increase in fuel economy using ECO button in mixed driving - very noticable difference.

When I need AC, I stick with recirc. mode for max. efficiency.

Any other similiar observations out there ?

Also see:

Rennlist Discussion Forums > Water Cooled Technical Discussion Areas > 997 Forum
A provocative A/C question.

schnell987

My understanding is that the ECO button turns the AC compressor on/off. the default is "on". By pressing the ECO button, the compressor is turned off (the light goes on) and you gain power and better fuel economy. I always keep the ECO button "OFF" when not using the A/C - simply to get more power. I may be wrong, but this is my understanding.

Hope that helps.
Kevin

ELUSIVE

That is my understanding as well.

Renn 951

Yes, you will see a noticeable difference in the miles per gallon displayed on th trip computer when the Eco button is pressed to cut off the AC compressor.

pcar964

How the hell can you notice a 1 mpg difference? Do you seriously monitor your gas mileage to within 1 mpg in your PORSCHE?

Jim Michaels

I was wondering the same thing. One mpg would seem to be well within measurement error; especially in "mixed driving", which is hard to control in terms of replication. On the other hand, driving with ECO on should certainly save some gas, and one or two mpg sounds about right to me.