https://www.fcsdchemicalsandlubricants.c...20Synthetic.pdf - Specs for the Motorcraft 5W-50.
http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007513239_201302211620.pdf - Specs for the QSUD 5W-50.
Looks like the Motorcraft starts off very thick compared to the QS, but the QS has a better VI.
http://www.redlineoil.com/product.aspx?pid=135&pcid=21 - The Redline 5W-50 is just as thick as the Motorcraft at 100C, but I'm sure the HT/HS is much higher than MC. It will hold its viscosity over the OCI, whereas the MC probably won't. Use the MC or QS if you won't be tracking it at any time during the OCI, but if you will be tracking it go with the RL. You just won't be in compliance with your warranty.
Good luck finding either the QS or RL 5W-50. The one place that I can find RL locally carries the 5W-30, 10W30 and 20W-50 and won't special order anything else for me. I guess there's always Amazon if you order a case at a time.
I know you said that Castrol is a no go, but their 5W-50 is right between MC and QS at 100C and the VI is pretty good. It's on sale right now at AAP for $30 for 5 quarts and a Fram Ultra. You won't be able to beat that price with any of the other options available.
http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007513239_201302211620.pdf - Specs for the QSUD 5W-50.
Looks like the Motorcraft starts off very thick compared to the QS, but the QS has a better VI.
http://www.redlineoil.com/product.aspx?pid=135&pcid=21 - The Redline 5W-50 is just as thick as the Motorcraft at 100C, but I'm sure the HT/HS is much higher than MC. It will hold its viscosity over the OCI, whereas the MC probably won't. Use the MC or QS if you won't be tracking it at any time during the OCI, but if you will be tracking it go with the RL. You just won't be in compliance with your warranty.
Good luck finding either the QS or RL 5W-50. The one place that I can find RL locally carries the 5W-30, 10W30 and 20W-50 and won't special order anything else for me. I guess there's always Amazon if you order a case at a time.
I know you said that Castrol is a no go, but their 5W-50 is right between MC and QS at 100C and the VI is pretty good. It's on sale right now at AAP for $30 for 5 quarts and a Fram Ultra. You won't be able to beat that price with any of the other options available.
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