Maker
MakerSolid outlineFrom the maker’s own document: press kit, spec sheet, towing guide, body builder guide or owner’s manual. We keep a copy and record the page, table and row it sits in.
Methodology · updated Oct 8, 2026 · documents checked Oct 12, 2026
How we source the numbers
Every number on 4wd.ai has a source, and the maker’s own documents come first: 1,356 press kits, spec sheets, towing guides and manuals behind 121,551 numbers. Where a maker publishes nothing, a magazine test, dealer or spec site may fill the gap, marked as third-party. What we work out ourselves is marked as an estimate and carries its range. Ratings are never estimated or taken from a third party.
01 / Sources
Where the numbers come from
We read the maker’s press kits and spec sheets, towing guides, body builder guides, owner’s manuals and price lists. Only when none of them gives a number do we take it from a magazine test, a dealer page or a spec site: one figure at a time, with the page it came from, under the Third-party mark. Any maker figure for the same configuration wins over it, and a rating never comes from one. We don’t copy other spec databases wholesale.
Every number keeps its document, where in it it sits (page, table, row), a saved copy of the document with its checksum, and exactly which configurations it applies to: model year, market, trim, cab, bed, engine, drive. A number that holds for one trim is never shown for another. “Up to 7,500 lb” stays a ceiling; it is not pinned on one configuration.
When two documents disagree, we keep both and flag the difference instead of picking one quietly.
- maker documents
- 1,356
- sourced numbers
- 121,551
- configurations
- 10,596
- vehicle generations
- 96
02 / Evidence
The four evidence marks
Maker
Estimate ±
Third-party
Owners
03 / Estimates
How estimates are worked out
- Tire size: the diameter comes from the size code. A 265/70R17 is 17 in of wheel plus two sidewalls of 70% of 265 mm: about 31.6 in. Real tires measure a little different, so it is a nominal figure.
- Bigger tires raise everything by half the growth in diameter: the axles, the body and the differentials.
- A suspension lift raises the body and what is bolted to it. A differential on an independent front suspension is bolted to the frame, so it rises with the lift; a solid axle’s differential only rises with the tires.
- Angles: from the maker’s approach, breakover and departure angle, the tire radius and the overhang, we recover how high the limiting point sits, move it with the lift and tires, and solve for the new angle.
- The ± range: when a maker doesn’t publish the overhangs, we use the average share for the class and show how far the answer moves if that guess is 10% off.
- Speedometer and gearing: arithmetic on the two tire diameters and the maker’s axle ratio.
Worked example
2027 Nissan Frontier PRO-4X
- Stock tire 265/70R17: about 31.6 in
- A 285/75R17 instead: about 33.8 in, so everything rises by half the difference, 1.1 in
- Add a 2 in lift: the frame-mounted front differential gains 3.1 in; the rear axle’s differential stays at +1.1 in
Ratings are never estimated. GVWR, axle ratings, payload, towing, tongue weight, GCWR, roof load and wading depth come from a maker document or not at all, never from a magazine, a dealer or a spec site. We don’t work out a payload from GVWR minus curb weight and publish it as a rating.
04 / Gaps
What “not published” means
“Door label”: the maker prints it only on the certification label and tire placard on each vehicle’s door jamb. That is where GVWR, the axle ratings and payload live. “Not published”: the maker’s documents don’t give it, or send you elsewhere, and we say where (“Jeep points to jeep.com”). Either way we say so (519 times in the data) instead of guessing.
A dash (—): we haven’t found the number in the maker’s documents we have. It may exist in one we haven’t read yet.
n/a: it doesn’t apply: a two-wheel-drive truck has no front differential and no low range.
05 / Comparisons
How vehicles are compared
- One entry per model: its newest generation and the newest model year we have that publishes the number, at most two years older than its newest.
- Its best configuration counts, factory packages included, and the package is named next to the number. The same number leads its page, its search result, its card and its row in a ranking.
- Fleet-only configurations, such as police and special-service trucks a retail buyer can’t order, stay on their model’s page, labelled, but never count toward its headline numbers, its place in its class or a ranking.
- Ground clearance means the maker’s single ground clearance figure. A maker that only prints clearance at the differentials is shown, not ranked against it.
- Towing and payload are compared within one market, and pickups within their size, because makers rate them differently.
- A class comparison needs at least 5 vehicles with the number. See the rankings.
06 / Corrections
Report a wrong number
Email hello@4wd.ai with the page, the number, and the maker’s document that shows the right one: a link, a page number, or a photo of your door label.
We check it against the document. If we were wrong, we fix the number and its source. If two maker documents disagree, we show both. We don’t change a maker’s number because a dealer, a forum or another website says otherwise.
The data lives in version control, so every change to a number is kept with its date. Every figure we set aside, and every one two of a maker’s documents disagree about, is in the public log, what we corrected, with the document and why.
07 / Independence
Who decides what we publish
4wd.ai is independent. No maker, dealer or parts brand pays for a place in a ranking or sees a number before it is published. Maker names identify the vehicles and their documents, nothing more.
If we add links to parts shops later, they will be labeled, and they won’t move a number or a place in a ranking. The numbers are a starting point, not engineering advice: weigh your loaded rig before a big trip.