Method & sourcing

Where the data comes from

Every vehicle on this site is identified by its manufacturer SKU (for example ARA7604V3T1). For each SKU we start from the manufacturer's own product page and its official exploded-view parts diagram for that exact SKU. We don't transcribe numbers by hand: a small extraction script reads the structured product data embedded in the archived product page and the part-ID list embedded in the archived exploded-view diagram, and writes out one JSON record per vehicle. Every displayed spec cell carries the source page it came from and the date we checked it.

Normalizing without changing the meaning

Manufacturers don't write specs consistently across generations — the same gear ratio might be written 4.3 on one generation's page and 4.30:1 on the next. Before comparing two generations, each value goes through a normalization step (numbers are parsed and compared numerically; short phrase fields like connector types are split on commas/slashes, sorted and compared as a set; free-text fields are case-folded and have "and"/"&", punctuation and extra whitespace ignored, so Painted, decaled and trimmed and Painted, Decaled, Trimmed read as the same value) so that a pure notation change doesn't get flagged as a real spec change, while an actual value change still does — Painted becoming Unpainted is still flagged, because the words themselves differ. This logic lives in one place in the code and is covered by tests that deliberately break it to make sure the tests would actually catch a broken comparison, not just a passing one.

One field is flagged instead of compared: product weight. When only one generation's weight is noted by the manufacturer as measured with electronics installed and the other isn't, the two figures aren't on the same basis, so we mark it "not directly comparable" rather than reporting a weight change that might just be a measurement-basis change.

Parts diffs

Exploded-view diagrams list a part ID for every component shown. We deduplicate each generation's list and compare the two as sets: an ID in both is "shared," an ID only in the newer generation's diagram is "new," and an ID only in the older generation's diagram is listed as not appearing on the newer diagram. That last category is a diagram fact, not a claim that the physical part was discontinued or is incompatible — a part can still be used even if a later diagram doesn't happen to list it separately.

We don't have part names for any part ID on this site, because the exploded-view diagrams we've archived label parts by number only. Rather than guess a name from context, we show the bare part number and link it to the manufacturer's own product page for that part number, so you can see the current name and fitment yourself.

What we won't do

• We don't quote the manufacturer's marketing copy or manual text. Every sentence describing a vehicle on this site is written from scratch from the structured spec/part data, and a build check scans every published page for long runs of text that match archived manufacturer copy and fails the build if it finds one.
• We don't reproduce official photos, logos, exploded-view diagrams or manual pages.
• Links to a part's manufacturer page are plain, un-tracked links to that part number's own page, labeled with the part number itself. We don't add store-style calls to action or figures around those links, and a build check enforces that.
• We don't publish a comparison built from data we haven't independently pulled and verified for both generations. If we only have one generation's numbers, the page says so instead of guessing the other one.

Staying current

Manufacturers revise spec pages after launch. Every page shows the date each side's data was last checked. Data older than a few months triggers an internal warning to go re-check the source before the next update, rather than silently getting stale.

Independence

This is an independent, unofficial project. It is not affiliated with, endorsed by, or operated on behalf of Horizon Hobby, ARRMA, Losi or Axial.