Originally Posted By: KCJeep
I am a huge fan of both and use them both extensively. Edge 0w40 is the bomb.com for extended OCI's and IMO is the best oil sitting on the shelf at Wally's. Magnatec performs way beyond it's price point and is an amazing bargain.
I can do 10k OCI's with Edge 0w40 without needing to spend money on a UOA I know I am still dumping good oil at 10k. Magnatec is awesome for shorter OCI's doing an 8k run of it right now in the Lincoln but I am not real comfortable pushing it much beyond that.
Win - win.
^^^ what he just said.
Edge 0W-40 is their best PCMO product, it's PAO based (last time I asked Castrol) and is designed for long European OCI of 20,000 miles / 30,000 KM / 2 years in MB and BMW etc and high performance applications for it's Porsche A40 spec.
There has been some excellent UOAs from Castrol Magnatec (North American - ILSAC grades) that show an obvious drop in iron wear metals, but it also shows the TBN is getting close to 1 by 9,000 miles. The Magnatec is still in it's viscosity grade, so good shear stability. The Magnatec was a semi-synthetic (5W30, 10W30, 10W40 - Oz) or full synthetic (0W20, 5W20 ) but slowly the range is being updated to mostly full synthetic (5W30 now). Castrol don't say, but I assume the Magnatec synthetics are Group III.
It's obvious Castrol have three levels of products: Edge > Magnatec > GTX. But they did such an excellent job in formulating the Magnatec that it can overshadow it's big brother Edge.
IMO -
Best Castrol oil: Edge 0W40
Best Bang for your Buck oil: Magnatec - but keep the OCI to about 8000 miles. For longer go Edge EP / Gold.
There is one exception to the above, Magnatec 5W30 A3/B4 in Australia and NZ, it's a full synthetic oil formulated to Euro long-life standards (high HTHS, high TBN, high SAPS) rather than American fuel economy standards. Just the stuff for taking your V8 Interceptor through the outback in a Mad Max style adventure.