Originally Posted by MonsterM
I am curious about "warming" up the car myself. The other day I let my friend drive my car (the car was parked with the engine running for about 10-15 min since it was about 20 degrees outside). He drove it for about 1.5 - 2 miles and then redlined it while merging on the highway and the car shifted at 7K. IMO it just did not feel right.
It's all about the oil temp. If the oil temp is up the engine should be OK. that said letting the car idle will not warm up the transmission fluid, gear oil in the rear end, etc. so better to drive it gently until the oil temp comes up, then go for the redline.
Now a whole 'nother thread could probably be started as to exactly how warm the oil should be before you spin it out...