Someone I trust when it comes to motors says his Audi 2.8 V6 motor needs about 1 quart of Red Line 30WT every 3k miles, but consumption will increase to 1 quart every 400 miles with Red Line 40WT. He says the thicker the oil, the higher the oil consumption. With lower viscosity oils he also sees more oil in the PCV breather hoses. Keep in mind he uses single weight racing oils. Usually, it's accepted that thicker oils will tend to reduce oil consumption, so I wonder what's up with this topsy-turvy result? Any thoughts, ideas, theories...? PS: Does anyone know the HT/HS of RL 30WT and RL 40WT?