Why does GM retard timing at colder engine temps?
Thread Starter
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Why does GM retard timing at colder engine temps?
Why does GM retard timing by a few degrees in cold engine temps? Is it for some sort of emission purpose or is it to allow the engine to run better at colder temps or will the engine run better at colder temps with no retarded timing?
Thanks!
Thanks!
Safety Car
Joined: Aug 2008
Posts: 4,344
Likes: 48
From: San Marcos CA
While an extra degree or two will raise the idle speed, my guess is that the later spark and therefore later combustion will be hotter coming out of the exhaust port to heat up the casting and also the catalyst will light off sooner.
