Sam’s website recommended Pirelli’s Scorpion tires for my RX350 SUV, so I had four of them installed, with recent date codes. Reviews said these tires had a softer ride than the original Michelins, which is what I was looking for. The ride did seem softer, but was also more jittery. After a few days of driving I noticed the same vibration was present on all road surfaces, and was pulsating, not random. I checked cold tire pressures. Instead of 30 PSI, they were set to 36, 37, 37, and 39 PSI. I set them all to 30 PSI, but this did not help the vibration. So I returned to Sam’s and had them re-do the balancing (though they were reluctant to do so). This did not improve things, so I went to my car’s dealership and spent an additional $100 of my own money for them to balance the tires. They found that the tires could not be balanced to stop the vibration. They then did a Road Force Test, which revealed that 3 of the 4 tires were out-of-round beyond acceptable limits, and the 4th tire was right on the edge of failing the test, not in just one test, but in both the axial and radial tests. The dealership was kind enough not to charge me for this test, which normally costs $250. The dealership also told me that though they do recommend Pirellis for their cars, they do not recommend them for their SUVs. I checked various tire dealer websites and found that Sam’s is the only one that recommends Pirellis for my SUV. I took the test reports back to Sam’s, and asked for replacements with Michelins, at an additional cost of $205 to me. They were reluctant to credit me for the bad tires, and a senior manager (not the tire dept. manager) had to get involved before they agreed to credit me for the defective tire set. A couple weeks later, I drove out with a set of four Michelin Primacy MXV4s. The vibrations had gone away. I later noticed that one of the four tires had been in storage for over 1.5 years! It also had a faded appearance, and some stains or marks on the outer sidewall surface which the other three tires did not have. I contacted Michelin on their website, gave them the details, and was given a case number and told that they would take care of it. I had to visit Sam’s and have them call Michelin to discuss my case, which I did. The Michelin rep who answered the phone when at Sam’s had a completely different take on the situation. Her view was that since I had driven with that tire on my car, I could not return it, and Sam’s convinced her that since I had returned the previous set of Pirellis, I did not qualify for Michelin’s 30-day Satisfaction guarantee. Even stranger, the Michelin lady told me that if I returned one tire, I would have to return all four! So now I am stuck with a tire that is going to have tire-rot before my other tires (I drive less than 4k miles a year, so tire-rot kills my tires long before tread wear does). I made the mistake of trusting Sam’s tire dept. Any reputable tire dealer would have sent the 1.5 year old tire right back to Michelin, or at least would have informed me about the situation before it was too late. While the Michelin tires are good so far, I give one star due to Michelin's inconsistent customer service and their inept inventory management system.