I installed a Hayden High Performance 512 transmission cooler on my 2005 Civic automatic. Temp went from 180 to 120 when idling in drive for 10 minutes in 70 degree weather. My question is what is the ideal temp for transmission fluid? Is 120 degrees too cold? I live in big mountains and I would think it could use all the cooling it could get. Is 120 ok or too cold?