I asked mobil what the NOAK was for 5w-30. Amsoil tested it as 9.7%. This was the response I got from them.
quote:I personally think this is an old trisynthetic number. I also don't believe this guy bc Amsoil has incredible NOAK numbers and great cold weather performance. And no this is not a plug for Amsoil. I wanted to point out that M1 10w-30 is 6%, 0w-40 is 9%. 12.9% just doesn't fit in. The Mobil NZ site I believe is where I obtained the 0w-40 NOAK. [ October 24, 2003, 08:29 AM: Message edited by: buster ]
Thanks for your request. The NOACK volatility is currently typically 12.9% for Mobil 1 5W-30. An engine oil's performance is based on a variety of physical and chemical properties and performance features, including low temperature cranking and pumping viscosity, high temperature high shear viscosity, fuel economy, catalytic converter protection, etc., which all must be balanced. For example, altering the product to lower the NOACK volatility could adversely affect low temperature viscosity and fuel economy performance. You should use engine oil with the SAE viscosity grade and quality level as recommended in your vehicle's owner's manual. MJRoe Technical Support Engineer