What is the difference between "will" and "would" in this example?

Question

Here are the examples:

• The car won't start.
• The car wouldn't start

Answer 1

"The car won't start" - generally a statement of fact (either about the future or, often, effectively about the present).

• "I'm trying to start the car, but it won't start." (Or: isn't starting)
• "The criminals sabotaged his car. When he returns next month, he'll find that it won't start." (Or: doesn't start)

"The car wouldn't start" - either a conditional statement (which may express contingency or tentativeness) or a statement about the past. Some of its uses are more or less interchangeable with "won't start" but express greater tentativeness:

• There's no point in trying the car, because it wouldn't start [= wouldn't start if we tried it = a more tentative equivalent to won't start if we try it].

The past use of "wouldn't" can also effectively be almost equivalent to "won't", if the context makes clear that the issue is believed to be ongoing:

• I wanted to go into town, but the car wouldn't start. It needs to be repaired before we can go anywhere.

However, in other cases it refers to a past situation that no longer obtains or which might no longer obtain, and so it is clearly distinct from "won't":

• The car wouldn't start (before) but it will now.
• When I tried it, the car wouldn't start. But if you try now, perhaps we'll have better luck.

Answer 2

Basically both of them mean the same and I say it again Basically.

However when you use won't or will, your trying to imply that the level of certainty is higher and you're quit sure about it. Example:

I will drive to work

basically means that your are certain. On the other hand would is a type of "being not sure". It is like you don't know if it's going to work for you or in your example if it is going to start eventually. Example:

I would drive to work

NOTE

There are other uses of these words One of which is "Desire" for will and "Willingness" for would, So this is the reason I said they are basically the same because when you would to do something..., it means that you are not certain. However when you will do something..., means that you are sure about it.