fredinstl wrote:
I am going to have my asphalt driveway removed and replaced by a
concrete driveway.
The driveway is about 1000 sq ft, with some slope.
I have a couple of bids already in. By code, it will be 6" at street.
One contractor suggested to go with 5" instead of the typical 4" for
an extra $550. Is that worth the extra expense ?
I was also wondering whether I should (or not) add wire or fiber mesh.
Somehow, I was told by one contractor no charge for that. Why would
they do it for free, and what's the benefits ?

Can't imagine what fiber mesh is good for. Wire or (better) rebar
accomplishes the following:

When there's a slight perturbation in the ground, or freezing/thawing
cycles, the concrete cracks. The rebar prevents the opposite sides of the
crack from moving vertically or horizontally. In other words, you simply
have a hairline crack instead of a two-inch step or a one-inch gap.

There are often posts here about what to use to fill a gap in a concrete
drive. In ALL cases, it's a drive without rebar.