Need Advice Regarding Speeding Ticket Defense

Hi everyone, I recently got a ticket for 80 on a 60 and I am trying to fight it. I noticed that while the ticket says that I was in a 60 zone, the officer made an error and he actually lasered me in a 40 construction zone. My question is, should I use this as a defense to cast doubt on the officers testimony? Or will it just make me look bad and potentially increase the fine (I believe its doubled in that zone). Any help appreciated thanks

Unless you were speeding in a 80 zone, you would basically be providing the courts evidence that you were actually speeding +40 in a 40kph construction zone.

Out of court fine for 80 in a 60 zone (3 demerit points)

Set Fine: $3.75 x 20kph = $75

Victim Surcharge: $15

Court Fee: $5

Total Fine: $95

Guilty conviction at trial for 80 in a 40 construction zone (4 demerit points)

Set Fine: $14 x 40kph = $560

Victim Surcharge: $125

Court Fee: $5

Total Damage: $690

Hmmm that's what I thought thanks