Hello, I own a 06 Lexus IS250 AWD AT with 141k miles on it. Today I drove it about 100 miles on a 90 degree weather at an average of 80 mph; I spent about 3.5 hours driving in total, 1 hr on a stop-and-go, and the rest on the highway; about 40 min on idle in neutral. About 30 miles away from...