Comparison of Superchargers
The table below was transferred from Corky Bell's book Supercharged! ISBN # 0-8376-0168-1 Page 8
| Characteristic | Roots | Centrifugal | Screw |
| Low Speed boost capability | A | D | A |
| High boost - Pressure capability (10+ psi) | B | A | A |
| Fast boost rise | A | B | A |
| Thermal Efficiency | C | A | A |
| Volumetric Efficiency | B | B | A |
| Ease of Intercooling | C | A | C |
| Power Loss through supercharger | C | C | C |
| Simplicity of installation | B | A | B |
| Noise | C | C | C |
| Vibration | B | B | B |
| Space Requirement | C | B | C |
| Installation Convenience | C | B | C |
| Cost | B | A | C |
| Score | 2.69=B- | 3=B | 2.77=B- |
A= Excellent-4; B=Good-3; C=Fair-2; D=Poor-1
The final score is the total points divided by the total. I am getting the average of all the scores.
Root Score: 2.69 is B-
A-2 = 8
B-5 = 15
C-6 = 12
Centrifugal: 3.0 is B
A-5 = 20
B-5 = 15
C-2 = 4
Screw: 2.77 is B-
A-5 = 20
B-2 = 6
C-5 = 10
Here is another comparison of supercharger types:
| Type | Fix Displacement | Internal Compression ratio |
| Roots | Yes | No |
| Centrifugal | No | Yes |
| Screw | Yes | Yes |
Thermal Efficiencies of typical superchargers
| Type | Et (%) | Temp increase with 1 psi |
| Roots | 55 | 18.5 |
| Screw | 70 | 14.6 |
| Centrifugal | 75 | 13.6 |
| Turbocharger | 75 | ??? |