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FuelEconomy.gov website screenshot

FuelEconomy.gov

US Department of Energy REST API providing official EPA fuel economy ratings, vehicle specifications, CO2 emissions data, and energy cost comparisons for all model years from 1984 to present. Administered by Oak Ridge National Laboratory for the DOE and EPA, the API offers free, unauthenticated access to vehicle lookup menus, per-vehicle MPG records, emissions data, current fuel prices, and community-contributed real-world fuel economy data.

agent aware

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles FuelEconomy.gov the way a machine reads it — 17 machine-readable artifacts across 6 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — FuelEconomy.gov scores 39.4/100 (thin), with a separate agent-readiness read of 39/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 39.4/100 · thin
Contract Quality 15.8 / 25
Developer Ergonomics 1.7 / 20
Commercial Clarity 5.8 / 20
Operational Transparency 0.0 / 13
Governance 8.8 / 12
Discoverability 10.0 / 10
Regulatory · Government & Public Sector 3.6 / 15
Agent readiness — 39/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile FuelEconomy.gov

Each block below is one kind of artifact we hold for FuelEconomy.gov. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 6

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

FuelEconomy.gov Emissions API

EPA tailpipe emissions data per vehicle

FuelEconomy.gov Fuel Prices API

Current US fuel prices used by the FuelEconomy.gov platform

FuelEconomy.gov Menus API

Navigation menus for year/make/model vehicle lookup

FuelEconomy.gov User MPG API

Community-contributed real-world MPG data

FuelEconomy.gov User MPG Menus API

Navigation menus for community MPG data lookup

FuelEconomy.gov Vehicles API

Retrieve EPA fuel economy and specifications for specific vehicles

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Fueleconomy Rate Limits

0 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

Cost, billing, and metering signals for API financial operations.

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Fueleconomy Context

7 classes · 75 properties

JSON-LD

Spectral Rules 1

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

FuelEconomy.gov API Rules

5 rules · 3 warnings

SPECTRAL

JSON Schema 4

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

FuelPrices

8 properties

JSON SCHEMA

MenuItems

1 properties

JSON SCHEMA

Vehicle

65 properties

JSON SCHEMA

YmpgVehicle

7 properties

JSON SCHEMA

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Fueleconomy Domain Security

TLSv1.2 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

Recommended x-agentic-access execution contracts for AI agents.

Fueleconomy Agentic Access

12 operations

12 operations · 0 acting

AGENTIC

Resources

Every other property we hold for FuelEconomy.gov — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 1

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Access & Security 1

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

Other 2

Properties that don't map to a standard resource type

← All providers · Data indexed from github.com/api-evangelist/fueleconomy · machine-readable index on apis.io