Wheel alignment…
Important stuff.
Yes, you want to deal with a shop you trust. First and foremost you want to use a shop that uses the latest high tech equipment. The latest equipment uses technologies that were not available years before. It doesn’t matter if your car predates this equipment. A more precise alignment will benefit any car. Yes, I see that some are balking at a $100 alignment. Expensive, high tech equipment has to eventually pay for itself.
“Checking” alignment:
If you put a vehicle on the rack to check the alignment the equipment and the tech’s time is already in use. You might as well have the car aligned by that point. Alignment equipment will show very clearly and precisely if any suspension components are damaged or worn.
Different cars have more or fewer alignment parameters. The alignments are camber, caster and toe.
Older and more high tech cars usually have all three of these available adjustments. Many just have toe adjustability. Some cars, such as the E30 BMW have no available adjustment at the rear.
Alignment and tire wear:
Yes, most motorists are primarily concerned with tire life. There are other, more important reasons to have a correct factory spec, or driver preferred alignment. Incorrect toe chews up tires faster than anything else. Most cars have a degree of negative camber for improved cornering. Negative camber means the inside of the tire is pressed into the pavement more than the outside. This will cause the inside edge to wear faster than the outside but improves cornering by causing the tire to “lean” into a corner similar to how a motorcyclist leans a bike in a turn.
Modern cars have suspension designs that actually manipulate camber under cornering and camber and toe under braking. These technologies improve cornering and straight line stability under braking. At uniform speed and in a straight line these angles return to their less aggressive settings to improve tire life.
The idea of a fresh alignment with a set of new tires:
Quality tires are a miracle of engineering and are not cheap. An alignment is an insurance that one of your nice new tires is not being presented to the asphalt at the incorrect angle from mile one. An alignment also shows that parts of the car are not worn or damaged. An alignment means that the car is tracking the road straight and cornering is as immediate and precise as the factory intended. Do it, really.
Rotation:
Tire rotation does reduce wear but comes at a price. Front and rear wheels are usually angled differently. This means that a tire performing service at the rear will need time to scrub in to work optimally at the front. During this wear in time the tires are not performing at maximum. Some rear drive cars cannot be rotated as the rears are wider than the fronts. I do not rotate so that the fronts and rears can do their individual jobs best at all times. Yes, this does mean I buy tires more often. If you rotate, reduce scrub in time by doing it often.
It makes me sad to see how many people assume the purpose of tire shops and dealer service departments is to rip you off.
Yes, we want to put food on our tables but we also want you to be safe. We want you to get the most satisfaction possible out of ownership and use of your vehicle.
Edit:
I read that you are buying the tires two at a time. I would recommend that you get the second pair as soon a possible, and wait to get the alignment then. But again, only if there is not going to be a long period of time pass between the two purchases.
It would be best to replace all four at the same time unless one or two tires are damaged or excessively worn.