Just Because Your Car is in Neutral Doesn't Mean it is Neutral
I've been doing some work on my Hummer recently and I decided to get the tyres replaced while I was at it. There was still a legal amount of tread left on them, but since my Hummer has been driving in wet conditions a lot (in Thailand) it seemed the prudent thing to do.
While the new tyres weren't cheap, they weren't too expensive considering that if I liquefied one it would pretty much fill a barrel of oil. But one thing they did ask me at the tyre place, the thing that they always ask, was, “Do you want us to check your car's alignment?” No, I did not want them to check my car's alignment. I am very familiar with my car's alignment. My Hummer is aligned with the forces of evil and there is nothing they can do about it.
If you are asked if you want your alignment adjusted when you get new tyres, just say no, unless there actually is a problem. I know the tyre places need to make money, but they can make money doing stuff that actually needs to be done. It's good for their souls, and you can think of it as doing your bit to improve the efficiency of our economy.
One way to tell if your car needs its alignment adjusted is if it has uneven tyre wear. In addition, there is also an easy test that can be done that requires only three conditions:
(1)A straight stretch of road.
(2)The willingness to take your hands off the wheel for a short period of time, and
(3)My not being anywhere in the vicinity when you do this.
If, when you take your hands off the wheel, the car continues straight or pulls slightly to the left (or to the right in countries that drive on the wrong side of the road) then your alignment should be fine. If your car instead pulls to the right and you end up having a head on collision with oncoming traffic, then your car's alignment is the least of your worries, so no problem there either.