i have been using redline 10w-40 for awhile, just change to 5w-40, i notice the oil warm up faster. coz usually in the morning on the first startup for 10W, it takes about 1 minute of slow drive (usually i drive below 2000rpm) for the car to move up to 2nd gear. but with 5W, it only takes about 30-40 sec. however, i notice the engine is noisier.