If you haven't changed any of the load characteristics, between the old tires and the new tires: such as more weight either side, front or back, any corner, tire pressures, etc, then the following applies. and even if you have changed some of the load characteristics you still have to consider the following.
New tires of any kind do not have the same characteristics as seasoned tires. Tires have to be seasoned, or in the case of race cars,they need to be warmed up and seasoned; that is why when you watch formula, sprint/Indy racing they weave back and forth on the track on the warm up lap before the green flag and why drag racers do burn outs.
New tire do not have the same grip because the compounds in the tires have not been energized if you will. The molecules in the tires have to bounce around hitting each other to generate the compounds into the desired results. This in the case of the Michelins as the Rep told you may take 7,000 miles. If you were to use the same tires on a PickUp truck and drive more aggressive it may only take 4 or 5,000 miles.
You may also notice a slight decline in fuel economy with new tires as they are not seasoned and they do not have the final desired compound reactions to the roads.
Also just a note; you and others may notice that when driving on newly paved roads, even with seasoned tires, that the grip and mileage is not as good as when traveling on seasoned roads.
For OPTIMUM grip and mileage, travel on seasoned tires, on seasoned roads. If you can find these conditions along with a perfectly level highway you will get the best economy: if you drive accordingly! But then again we do not live in a perfect world, so what you see and feel is what you get, until everything gets adjusted to your driving style!
ALL tires should be replaced when the warranty period ends. Because as per the Federal Law of the "Magnus Moss Warranty Act of 1975": (http://www.mlmlaw.co...es/undermag.htm OR http://en.wikipedia....ss_Warranty_Act): If a warrantied item fails and damages a non warrantied item/part, the manufacture has to pay for the damage to said parts: like fenders, air bags, wiring, etc. However, the warrantied item, in this case the tire, has to be presented for inspection to the manufacture's place of business. That means; pick up all of the tire pieces and take them along with what is left of the tire carcass to the manufacture's place of business/ factory dealer ( not just someone that sells the brand) even if you have to put the tire on top of your vehicle to get it there. The Mfg does not have to reimburse you for damages if you do not comply/do/follow this procedure!!
For more on the Magnus Moss act of 1975 just Google it! You are in their Ball Park and have to play by their rules: Not I don't like the rules!!!
The tires are most likely not unsafe, but If you slow down or don't drive as you would usually, because you "feel" they are unsafe, it will take longer for the tires to season.
Be safe, drive safe and look out for those that aren't driving safely or on the road with safe equipment!
AND most of all look out for people on motorcycles: especially those that wear black, which makes them very hard to see: because they blend in with the highway! Like tires; some riders have to be seasoned a few times, by hitting the pavement, that they blend in with; or a vehicle; before they wise up and wear High Visibility Clothing, that makes them easier to be seen !
For my credentials that may lend crediance to the creditably for what I have said; visit my profile. However the following has to be said:
Legal Disclaimer: What I have said is not to be taken as Legal Advice! Do your homework and decide for yourself and remember: "He said" does not work or count in any court of law!!
Safe Travels!
