# AC on startup? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [July 7, 2018, 3:22pm UTC](https://community.cartalk.com/t/ac-on-startup/120548 "2018-07-07T15:22:51Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\ **Post date:** [July 7, 2018, 3:22pm UTC](https://community.cartalk.com/t/ac-on-startup/120548/1 "2018-07-07T15:22:51Z")
When AC first came along, I was always careful to turn off my AC on shutdown and not turn it on at startup until the car had run for 30-60 sec. Nowadays I have just been leaving it on, as it seems to have a built-in lag before starting up. The purpose was to reduce stress on the engine. What do the au courant say? ---
**Author:** ![Docnick](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Docnick](https://community.cartalk.com/u/Docnick)\ **Post date:** [July 7, 2018, 3:37pm UTC](https://community.cartalk.com/t/ac-on-startup/120548/2 "2018-07-07T15:37:40Z")
I don’t know this guy called “au courant”, but all modern cars have a cut-out for the A/C on start up. This was covered in a previous post as well. Years ago you could buy a cut out relay to shut off the A/C when passing on a freeway. This gave you less need for flooring the accelerator and it improved fuel economy. Compressors are also more efficient now and the A/C no longer needs 6 HP or so as in the olden days. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [July 7, 2018, 4:03pm UTC](https://community.cartalk.com/t/ac-on-startup/120548/3 "2018-07-07T16:03:18Z")
Leave the air conditioner on, drive on , people with auto temp never touch anything except the temperature control.