This is not a correct statement.
The letter "A" is traction rating in the dry and again in the wet. Again it seems like these have not bearing on reality. I had some Good-years that were "AA" rating in the wet and my "A" Pilots kick their ass in the wet or dry
Information on Traction Grades:
Traction Grades
UTQG Traction Grades are based on the tire's straight line wet coefficient of traction as the tire skids across the specified test surfaces. The UTQG traction test does not evaluate dry braking, dry cornering, wet cornering, or high speed hydroplaning resistance.
The Traction Grade is determined by installing properly inflated test tires on the instrumented axle of a "skid trailer." The skid trailer is pulled behind a truck at a constant 40 mph over wet asphalt and wet concrete test surfaces. Its brakes are momentarily locked and the axle sensors measure the tire's coefficient of friction (braking g forces) as it slides. Since this test evaluates a sliding tire at a constant 40 mph, it places more emphasis on the tire's tread compound and less emphasis on its tread design.
In 1997, the UTQG Traction Grades were revised to provide a new category of AA for the highest performing tires in addition to the earlier A, B and C grades. Previously the A grade had been the highest available and was awarded to tires that offered wet coefficients of traction above 0.47 g on asphalt and 0.35 g on concrete.
Also another FYI
UTQG Temperature Resistance Ratings
Speed, loading and inflation can significantly impact a tire’s resistance to heat generation or build-up, which in turn can reduce a tire’s durability and service life. The UTQG temperature resistance test is conducted under predetermined standards for inflation and loading.
Grade C: Minimum performance level indicating the tire failed to complete a half-hour at 100 mph
Grade A: Maximum performance level indicating the tire withstood a 30-minute run at 115 mph without failing
Grade B: The tire passed 100 mph, but not 115 mph
The UTQG test standards also measure a tire’s resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel.Grade A: The tire performed well on both surfaces
Grade B: The tire performed well on at least one of the surfaces
Grade C: The tire performed poorly on one or both of the surfacesThe UTQG traction measurement notes a tire’s ability to stop on wet test surfaces of asphalt and concrete under controlled conditions. The rating is based on a low-speed (40 mph) wet braking test and generally indicates the traction capability of the tread compound in straight ahead braking.The UTQG treadwear measurement is an indexed representation of a tire's durability under optimum conditions. The treadwear grade is based on a 7,200-mile wear test conducted under controlled conditions on a standardized test course. Tires are measured for wear, and tread life expectancy is extrapolated to 2/32-inch of tread.
The letter "A" is traction rating in the dry and again in the wet. Again it seems like these have not bearing on reality. I had some Good-years that were "AA" rating in the wet and my "A" Pilots kick their ass in the wet or dry 
