What the Spec Sheets Get Wrong

Why this page exists

We built this site on a simple rule: every number traces to a manufacturer specification or a named published source, and where a figure cannot be verified we say so. Applying that rule across twenty-two comparisons produced a side-effect we did not plan for — a list of specifications that are widely repeated, easy to find, and not true.

None of this is fraud. Almost all of it is one bad row in a shared product database, copied by every retailer that draws from it. But the effect on a buyer is the same, and the fixes are easy once you know where to look.

The retailer product name is not a specification

Search for the Maxxis RAZR MT and dozens of dealers list it as “RAZR MT MT-772 (3-ply sidewall)”. That parenthetical is part of the product name in a shared retail catalogue. Maxxis’s own page never states a ply count — it describes an “armor sidewall design” and “dual-cord body-ply technology”.

The tire may well have three plies. The point is that the number everybody repeats did not come from Maxxis, and a buyer choosing it over a competitor on that basis is choosing on a catalogue string. Our sidewall guide covers how to settle it properly: federal marking rules require the actual ply count to be moulded into every sidewall.

A warranty that is not in the warranty schedule

Two large retailers advertise a 40,000-mile treadwear warranty on the Maxxis RAZR MT. Maxxis publishes a specific mileage-warranty table listing the RAZR AT-S, RAZR AT and RAZR HT. The MT-772 is not in it. Its general limited warranty runs to 2/32″ remaining tread or six years from manufacture — a workmanship warranty, not a treadwear one.

A separate retailer advertises a 50,000-mile warranty on the Federal Couragia M/T, which contradicts every other source and the norm for the entire category. No mud-terrain we have documented carries a treadwear warranty.

The load-rating discrepancy nobody flags

For the BFGoodrich KM3 in LT285/70R17, Tire Rack and SimpleTire list 126/123Q carrying 3,750 lb. Four other retailers — all citing BFGoodrich article number 53313 — list 121/118Q at 3,195 lb. The lower figure matches the industry standard for the size and load range, and matches every competing tire in it.

The gap is 555 lb per tire, or over 2,200 lb across an axle set. We publish the lower figure and flag the disagreement. If you are buying to a specific axle load, read the sidewall on the tire in front of you.

The same 126/123 and 3,750 lb pairing appears on the Toyo Open Country R/T Trail and the Goodyear Wrangler DuraTrac RT in the same size, from the same source. Three tires from three manufacturers sharing one improbable figure is the signature of a feed error, not an engineering coincidence.

Weights that are not close

One large retailer’s weight column is unusable. It lists the Falken Wildpeak M/T at 51.6 lb where Falken and tiresize say 63.3, the Nitto Trail Grappler at 58.45 lb against Nitto’s own 66.39, the Cooper Discoverer STT Pro at 41.5 lb against Cooper’s 62, and the Kanati Mud Hog at 51 lb against its manufacturer’s 61.4.

These are not rounding differences. A 20 lb error on a light-truck tire is the difference between two entirely different constructions, and weight is one of the few honest proxies for how much material is in a casing. Use retailer databases for price. Use the manufacturer for everything else.

Marking columns that are simply unpopulated

The same retailer reports “No M+S designation” for the Falken Wildpeak M/T, which directly contradicts Falken’s own site. It also asserts a three-peak mountain snowflake rating for the Kanati Mud Hog that its manufacturer, Greenball, does not claim anywhere.

An empty field rendered as a negative is worse than a blank. A buyer who needs severe-snow capability, or who is checking whether a tire is even M+S branded for a local winter regulation, is being given an answer where none exists. Our snow guide covers what the certification actually means.

Disclosure that changes by country

Toyo’s Canadian site describes the Open Country M/T as a “high turn-up, 3-ply polyester casing”. Toyo’s US site says only “high turn-up, tough polyester construction”, with no ply count. Same tire, two disclosure standards, and only one of them answers the question buyers ask most.

Cooper’s Discoverer Rugged Trek is a similar case in a different direction: Cooper’s own product page claims a three-peak rating for one metric size, Tire Rack lists “no” for two others, and Cooper’s specification PDF has no snow column at all. Treat it as size-dependent and check the exact size you are buying.

Sizes that do not exist, and part numbers that do

Atturo’s Trail Blade M/T is not made in LT285/70R17 — the size table jumps from LT265/70R17 to 33×12.50R17. Any listing offering you one should be treated with suspicion.

The reverse trap is more common. Federal’s Couragia M/T exists in LT285/70R17 under two part numbers, one Load Range D at 65 psi and one Load Range E at 80. Retailers list them interchangeably. Falken and Nitto both offer that size in Load C as well as E, with genuinely different tread depth, weight and capacity. The size is not the specification; the part number is.

How to check any of this in two minutes

Read the sidewall for construction: federal rules require the actual ply count and cord material to be moulded there. Read the manufacturer’s own product page for warranty and snow certification, never a retailer’s summary field. Read the part number, not the size, when load range matters. And when two sources disagree, prefer the one that matches the industry standard for the size — or assume neither and go and look.

That is the whole of our methodology, and this page is what it produced when we applied it properly.