Thank you for the pricing, Todd and thanks, everyone, for participating in this discussion.
I'm moving specifically to synthetic as this will help me deal with the extreme hot and cold weather conditions that we have in New Brunswick where winter temperatures can fall as low as -40°C. A block heater is not an option as my car has no access to an electrical outlet.
As per JD Power (see link below):
http://www.jdpower.com/autos/article...ic-Motor-Oils/
"Synthetic oil performs admirably in heat, but also offers many benefits in extreme cold. Petroleum-based motor oil thickens in cold temperatures, requiring the starter and battery to work much harder to start a cold engine. Synthetic oil is not as affected by low temperatures, and it will flow much easier at engine start-up. As an added benefit, the cold temperature properties allow it to be quickly pumped throughout the engine, offering much improved start-up protection against friction.
Custom-designed synthetic oils contain many additives. These keep the inside of the engine clean, and add additional engine protection for extended periods."
I would have preferred using Amsoil 5W-30 100% Synthetic High Performance Motor Oil which has a Pour Point of -51°C (-60°F). However, it is very pricey. A 946ml bottle sells for $13.99 + tax at Canadian Tire and never goes on sale.
I'm therefore going to use Mobil 1 Synthetic Motor Oil 5W-30 which has a Pour Point of -45°C (-49°F). Regular price for a 4.4L jug at Canadian Tire is $43.99 + tax ($10 + tax per litre). It went on sale in mid-Nov 2010 for $30.79 + tax ($7 + tax per litre). Will buy this when it comes on sale again.
http://www.canadapost.ca/shopper/ite...il-224w0289424
I will be maintaining the same oil change intervals as recommended by Toyota.