Anyone on a car allowance? need advice! around$1300 a month

[EDManual]

I can change from a company car to a car allowance. should I?

Thing is I do around 6500km a month. Thats 78,000km in a year.

This is what I figure:
Insurance : $600
Rego: $500
Tyres: 2 sets $800
Maintenance: every 15,000km * 5 *200: $1000
Interest on cars worth: $30000*.08=2400
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That equals $5300 and leaves $1300*12=$15600-$5300= $10300 for petrol and depreciation.

Hmmm

So i want an RTV ute on gas, gas cost ave .45/litre, car does 15l/100km, thats $6.75 per 100km. 78,000km / 100km =780*$6.75=$5265 for gas

Still have $5035 left for depreciation.

I believe you can claim depreciation as a deduction too, does this help me?

Now would I be getting a good deal or not?
What else can I do to help my income?