P/N Make Model 30um Filtering (wt 5) Overall Build Quality (wt 5) Media Surface Area (wt 1) Media Volume (wt 1) Price Paid (USD) (wt1.5) Final Grade
PF1218 ACDelco n/a F F B A- B- 0.80
EaO24 Amsoil n/a A A- D+ D F 3.02
B1428 Baldwin n/a D B- B- A- D+ 1.99
3510 Bosch n/a C B- A- B- C 2.44
B4361 Carquest n/a D C+ C+ C A 1.99
LF3679 Fleetguard n/a C D+ D+ D+ B 1.75
DL5 Fram Defense C C- C- C- A 2.07
DG5 Fram Double Guard C+ C- C- C- D 1.84
HM5 Fram High Mileage B- D D C- C 1.53
PH5 Fram Extraguard D+ D C- C+ B 2.00
TG5 Fram Toughguard C- C C+ B- C- 1.93
HP4 Fram Racing C- C+ A B- D 2.09
XG5 Fram Xtended Guard A- A C A C- 3.49
OPH1218 Full n/a D C+ A C C 1.89
HP-3002 K&N n/a B A- B+ A F 3.02
PH1218 Luberfiner n/a C- C+ C C B- 2.08
ML1011 Mann n/a B- C- A B C 2.37
MGL9100 Microgard n/a B- D D D+ B- 1.84
M1-302 Mobil 1 n/a B A A- A D 3.27
FL12A Motorcraft n/a D+ C- B C+ D+ 1.65
21060 Napa Proselect C+ B+ B- C A 2.87
1060 Napa Gold C+ A- B- C+ C 2.81
PG4631 Premium guard n/a D+ B+ C D A- 2.34
PPL34631 Proline n/a D C- F D A- 1.49
PO4011 Pronto n/a C+ C N/A N/A A 2.04
L34631 Purolator Classic B B- C+ D+ B+ 2.74
PL34631 Purolator Pure-one C- B+ A- B+ C+ 2.63
30-1218 Royal Purple n/a A A C- F F 3.09
S17 Shell n/a F F F F A 0.44
S5 STP n/a F F B B B+ 0.81
51060 Wix n/a C A- B+ B+ C 2.82
Grades based off general A, A-, B+, B, B-, C+, C, C-, D+, D, F scale
A being the highest grade and F being the lowest.
Better filteration earns a higher grade, better construction earns a higher grade
lower prices earn a higher grade, higher surface area and volume earns a higher grade. 
Final grade is calculated the same as a GPA based on the 4 point system
The higher the final grade, generally means a better overall filter. 
Catagories are weighted by importance, calculated weights are listed in column heading
Filteration and build quality are somewhat objective so you can make your own judgments

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