I have to agree with Lee Weber. You will do more damage to your engine starting at -20 with 15W-40 than you will by running a synthetic until the weather warms up.
Try the Amsoil 15W-40, it has "pour point" of -47 F. OR the Amsoil 5W-30 it has a lower "pour point" of -68 F. Both are Heavy Duty Diesel oils rated as CH-4/SJ oils. I have seen regular petrolium 15W-40 oil at -25 F that will not even pour from the container! Not good at that cold of a tempoerature!
Wayne
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94'SLT 4X4 AT/White in color. Factory Tow Hooks & Running Boards. Amsoil By-Pass filter, Amsoil Air cleaner,and all fluids are Amsoil. Optima "Red Top" batteries.
BD exhaust Brake, BD Torque Lock, BD Torque Converter, Dr. Performance Stage II Injection Pump. Mag-Hytec Diff Cover,Mag-Hytec Transmission Pan, Isspro Pyro, Boost,Oil temp Gauges mounted in 3 Gauge post mount. One gauge monitors Engine Oil, Trans, Diff. Temps.
Wayne Owen
[This message has been edited by amsoilman (edited 02-25-2001). ]
[This message has been edited by amsoilman (edited 02-25-2001). ]