PETROL prices have soared to a five-month high, with unleaded fuel set to climb above 140c a litre this weekend.
Unleaded fuel is about 20c more a litre than it was at the same time last year.
The rising cost is expected to put the bite on local tourism as cash-strapped families steer clear of driving holidays.
Martin Arnold, an economist at CommSec, said petrol prices had hit an average of 131c a litre and could rise in the next few weeks because of a tight oil market.
"They've hit fresh five-month highs and it looks like they will go higher over the next month or so, into the holiday season," he said.
Mr Arnold said the increase in the cost of unleaded fuel had added an average of $15 a month to a family budget.
RACV spokesman David Cumming said unleaded petrol hit 139.9c a litre in Melbourne last week, equalling the record prices reached last year.
"In view of the fact that the wholesale price has gone up since we hit 139.9, we could go over 140c this weekend."
Mr Cumming said people could change their holiday plans because of fuel prices.
"There is no doubt that tourism will be impacted," he said.