The Department of Transportation (DOT) is the US governmental agency that regulates all forms of transportation in the US. That includes air travel (FAA), rail travel, travel on water, and what we are interested in, roads (through the National Highway and Traffic Safety Administration – NHTSA – pronounced Nit-Sah). As part of that, NHTSA also […]

This article is about Winter and All Weather tires. It includes information about the tests involved. Winter and All Weather Tires: Updated January, 2026 I added a line or 2 about studded tires below. Updated Apr, 2024 In the Apr 8, 2024 issue of Tire Business, a trade newspaper for the tire industry, there was […]

Uniform Tire Quality Grading (UTQG) is a US system for passenger car tires to allow consumers to make better choices when buying tires. This article is about the details. What you should get from this page: UTQG ratings were a long time in gestation. The tire manufacturers resisted the regulation quite strongly. Their principal argument […]

If you came here to research what is causing your odd and/or uneven tire wear, I suggest you read this page first, then go here! Most tire wear occurs when cornering. Driving straight ahead is almost free. Put another way, there is a difference between “City Driving” and “Country Driving” and country driving results in […]

Tire Traction & Traction Testing – Wet: This article is about wet traction testing. It includes details of the UTQG rating test for (wet) traction. If you haven’t already, it would be better if you read my webpage on dry traction here. This page will make a lot more sense if you do. I address snow […]

This article is about dry traction testing. Read this one BEFORE reading the article on Wet Traction here. I address snow and ice traction testing here as part of the article on Winter and All Weather tires. The photo above is of a traction trailer and its tow vehicle. Below I will discuss how tires get tested […]

A Work in Progress Speed Ratings: Before we start, I want to remind everyone that these web pages are generally about passenger car tires. When I discuss something that doesn’t apply to passenger car tires, hopefully it will be obvious. Here’s what you should get from this page: Historical background: Speed ratings are a 1960’s […]