Should I?

[NotCoppingIt]

I wasn't sure whether to ask my question here or in the Speeding section but here goes.
I was recently pulled over for doing 118 in a 100 zone, reduced to 116. At the time I thought I was in a 110 zone which actually ended a bit earlier. I'm pretty sure that I was speeding but I'm wondering if it's worth going to court to explain a few other factors which may have contributed to my offending (driving a borrowed van with no cruise control and a possibly faulty speedo and unfamiliarity with the road I was on).
Is the purpose of going to court to get out of an offence altogether or can a judge reduce the penalty? If I go to court and am unsuccessful, will I be any worse off than I am now ($322 fine)?
Hopefully my query makes sense and isn't the stupidest thing you've read all day but I have no prior experience in these matters.

[Gravy]

Read this page first, then let us know if you have any further questions.

[Hardy]

There are several reasons why you might want to go to court:
1. To save your licence by being acquitted.
2. To avoid demerit points by being acquitted.
3. To avoid paying a fine.
4. To delay losing your licence.
5. To avoid a conviction.

Going to court to explain why you are guilty is relevant for points 3, 4 and 5 only.
You will note "getting a reduction" is not on the list.