Methodology

The formula

Each truck gets a rarity score from 1–10. The score is a weighted blend of three components:

rarity_raw = 0.45 · scarcity   (how few were built)
           + 0.35 · survivorship (how few survive)
           + 0.2 · demand       (how many people want one)

rarity = round(rarity_raw / 10)   // clamped to 1–10

The three components are each scored 0–100 so they're directly comparable. The weights are intentional: scarcity matters most because you cannot manufacture old trucks back into existence. Survivorship matters next — a truck that was rare new and rotted in the decades since is rarer than one that survived intact. Demand is the smallest weight because it's the only one that fluctuates with culture, not metal.

Component 1 — Scarcity

Based on the estimated total US production for that exact trim+engine+era combination. Toyota does not publish per-trim production figures, so we collect the best available estimates and note the source on every variant.

scarcity = 100 − 14 · log10(production_midpoint)

When sources disagree, we publish a band (low/high) and use the midpoint for the algorithm. Where Toyota's stated number disagrees with reality (e.g., the S-Runner's planned 800/month rate vs. the actual ~200/month), we show both numbers and explain which we believe.

Component 2 — Survivorship

What fraction of the original production is thought to still exist in driveable condition today. Sources include Hagerty insurance data, registry counts, and forum consensus. When we have no data we fall back to an age-based heuristic.

survivorship_score = 100 · (1 − survival_fraction)

Component 3 — Demand

A 0–100 score reflecting how actively the market wants one. Inputs include Bring a Trailer auction prices and frequency, Hagerty's "collector market" categorizations, the existence of dedicated registries, and whether the trim is on published "future collectibles" lists. This is the most subjective component and we mark every signal we use on the variant page.

Uncertainty

Every production estimate carries a confidence rating: high (Toyota confirmed or directly counted), medium (good triangulation between multiple independent sources), or low(community estimate without primary documentation). Low-confidence numbers are visibly labeled on the variant pages so you know what you're looking at.

Fact vs. lore

Every fun fact on the site is either sourced or marked as folklore. We split them into two arrays in the data file:

• Fun Facts — verifiable claims with at least one supporting source.
• Lore— folklore, unverified rumor, and disputed claims. Visually distinct on the page. Includes the "why we're not sure" note where relevant.

If a claim turns out to be wrong (e.g., the well-circulated "X-Runner shares its gearbox with the Lotus Elise" — both are Toyota gearboxes, but different units), we move it to lore with a disputedclassification rather than silently deleting it. The myth itself is part of the truck's story.

The current top of the Codex

For reference, the six trucks with the highest computed rarity right now:

Sources

Every variant page lists the sources used for that truck's production and demand scores. The recurring sources we trust:

• Wikipedia — Toyota Tacoma — for general timelines, repeated official Toyota figures.
• Hagerty — insurance + collector market data.
• CustomTacos, Tacoma World, and TTORA — long-running enthusiast registries with historical production threads.
• Bring a Trailer — current auction pricing and demand signals.

Spot a mistake?

The Codex is meant to be the most accurate public Tacoma reference. If something is wrong, send corrections — preferably with a source — to hello@tacomacodex.com.