Fuel Economy Calculator implementation

A source-bound implementation contract for Fuel Economy Calculator; deployment and executable qualification remain separate.

Status: VERIFIED_CLEANLifecycle: implementation-contract

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner: Guth Instruments
Lifecycle: verified-clean
Evidence ID: t4-091
Effect: Computation or source lookup only

Input and validation requirements

The formulas have no input validation for zero denominators or physically invalid fill-up data. Zero fuel makes MPG undefined (or Infinity in plain JavaScript), and zero distance makes L/100km undefined.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "miles_driven": 360,
    "gallons_used": 12,
    "gallon_type": "US"
  },
  "expected_outputs": {
    "MPG": 30
  },
  "working": "1. miles_driven = 360 mi.\n2. gallons_used = 12 US gal.\n3. MPG = miles_driven ÷ gallons_used.\n4. MPG = 360 ÷ 12 = 30 MPG."
}

Other records

01Overview 02Mechanism 04Qualification

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

VERIFIED_LEDGER.json
evidence-tranche4/tranche4-results.json