This question is likely to garner as many opinions as there are BITOG members and when passion is involved objectivity likely goes out the window. I have ran 4 different oils (counting the FF) in my FX4 (5.4L) and have UOA'ed all of them. The UOAs are listed towards the bottom of the post and the raw data is about as objective as it can be (leaving it up to the reader to decide). I also performed a few calculations using various oils, oil filters, and OCIs that show the differences between ST, MS5K, M1, M1EP, and SSO running various OCIs and filters. All of these are calculated based upon full use of the oil life and the length of the oil life is based upon what I believe they may be in my FX4 (they may not apply to other vehicles). Given my math is correct, there are some differences in cost, but provided the oil is used for the full life (and not dumped early), the cost differences are not so far apart as one may think. Thoughts?
Oil Costs:
Conventional:
ST (SuperTech) = $2.59/QT x 7 = $18.16 (bought in 5QT jugs @ WM)
MS5K (Mobil Super 5000) = $3.19/QT x 7 = $22.33 (bought in 5QT jugs @ WM)
Synthetic:
M1 (Mobil 1) = $4.39/QT x 7 = $30.73 (bought in 5QT jugs @ WM)
M1EP (Mobil 1 Extended Performance) = $5.39/QT x 7 = $37.73 (bought in 5QT jugs @ WM)
SSO (Amsoil Signature Series) = $6.90/QT x 7 = $48.33 (bought in 4QT jugs @ Amsoil PC)
Filter Costs:
Motorcraft (MC) FL-820s = $2.30 (AAP + code)
Fram Ultra (FU) = $7.53 (AAP + code)
Amsoil EO = $13.15 (Amsoil PC)
When we apply the miles to the cost, it becomes thus:
0.001705 per mile @ 12,000 miles per OC at a cost of $20.46 (ST + MC)
0.002052 per mile @ 12,000 miles per OC at a cost of $24.63 (MS5K + MC)
0.002117 per mile @ 25,000 miles per OC at a cost of $52.93 (SSO+ 2 MCs)
0.002117 per mile @ 20,000 miles per OC at a cost of $42.33 (M1EP + 2 MCs)
0.002202 per mile @ 15,000 miles per OC at a cost of $33.03 (M1 + MC)
0.002263 per mile @ 20,000 miles per OC at a cost of $45.26 (M1EP + FU)
0.002355 per mile @ 15,000 miles per OC at a cost of $35.33 (M1 + 2 MCs)
0.002459 per mile @ 25,000 miles per OC at a cost of $61.48 (SSO + EO)
0.002551 per mile @ 15,000 miles per OC at a cost of $38.26 (M1 + FU)
0.002647 per mile @ 20,000 miles per OC at a cost of $52.93 (SSO + 2 MCs)
0.002793 per mile @ 20,000 miles per OC at a cost of $55.86 (SSO + FU)