AKI (R+M)/2 to MON
Type a value in AKI to get it in MON instantly.
89MON
98 RON is posted as about 93.5 at a US or Canadian pump.
What it means
Where does that octane sit?
Approximate: the gap between RON and MON varies with the blend, typically 8 to 12 points. Use the grade your owner’s manual asks for.
The math
How to convert AKI to MON
AKI = (RON + MON) ÷ 2, and MON is typically 9 below RON, so AKI ≈ RON − 4.5.
Example: 93.5 AKI = 89 MON.
Every unit
That petrol on every scale
Tables
AKI to MON conversion table
| AKI | MON |
|---|---|
| 82.5 AKI | 78 MON |
| 84.5 AKI | 80 MON |
| 85.5 AKI | 81 MON |
| 86.5 AKI | 82 MON |
| 87.5 AKI | 83 MON |
| 88.5 AKI | 84 MON |
| 89.5 AKI | 85 MON |
| 90.5 AKI | 86 MON |
| 91.5 AKI | 87 MON |
| 92.5 AKI | 88 MON |
| 93.5 AKI | 89 MON |
| 94.5 AKI | 90 MON |
| 95.5 AKI | 91 MON |
| 97.5 AKI | 93 MON |
MON to AKI conversion table
| MON | AKI |
|---|---|
| 78 MON | 82.5 AKI |
| 80 MON | 84.5 AKI |
| 81 MON | 85.5 AKI |
| 82 MON | 86.5 AKI |
| 83 MON | 87.5 AKI |
| 84 MON | 88.5 AKI |
| 85 MON | 89.5 AKI |
| 86 MON | 90.5 AKI |
| 87 MON | 91.5 AKI |
| 88 MON | 92.5 AKI |
| 89 MON | 93.5 AKI |
| 90 MON | 94.5 AKI |
| 91 MON | 95.5 AKI |
| 93 MON | 97.5 AKI |
Quick answers
Quick answers
- How many MON is 1 AKI?
- 1 AKI is -3.5 MON.
- How many MON is 10 AKI?
- 10 AKI is 5.5 MON.
- How many MON is 93.5 AKI?
- 93.5 AKI is 89 MON.
The units
About these units
AKI (R+M)/2 (AKI)
Anti-knock index posted at US and Canadian pumps.
MON (MON)
Motor Octane Number, the harsher test.
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