Palm Beach Dyno is a Ford performance shop — dyno and remote calibration, fuel-system packages and builds. We tune on gasoline, on ethanol blends and on E85, which is how we ended up caring about blending arithmetic enough to build this.
The same engine our own staff use
This calculator uses the identical calculation engine as the tool inside our internal TechCenter — literally the same file, loaded by both sites. That is deliberate: two copies of the same maths drift apart, and we would rather not find out about it from a customer.
How it is tested
The engine carries 276 assertions covering every mode, all documented edge cases, unit parity and rounding discipline. The golden test vectors were generated from an independent reference implementation written in exact rational arithmetic — not captured from the code under test, which would only prove the code agrees with itself. A randomised differential test compared 605 scenarios across three modes against that reference with zero mismatches. The suite runs as a gate on every deployment.
Choices we made on purpose
- No octane figure. Ethanol's blending octane is non-linear and base-fuel dependent; a linear estimate is wrong. Reasoning →
- Ranges stay ranges. If your inputs are uncertain, the answer is a range. Collapsing it to a single number would be false precision.
- The seasonal band is always your choice. Never inferred from the date or your location.
- No tuning recommendations. The engine cannot produce a commanded AFR, lambda or timing figure. There is no such output in it.