I wonder if we're talking about two different tires here. The OEM tires that were on my '04. 5 3500 and are on my '06 3500 SRW are the LTX A/S tires. I had an '01 which came with the LTX M/S. I thought the M/S' were worlds better. Perhaps trucks going to places like CA and others that rarely see snow get the A/S from the factory instead?