Geelong Petrol Is Exempt From Victoria's Summer Smog Rule Until March

Every year on 1 November, Victorian petrol quietly changes its recipe. Refiners and importers have to make it less volatile, so less of it evaporates on hot days and feeds the brown haze that settles over Melbourne in a heatwave. This year, petrol from the state's only refinery has been given a pass.

One refinery, one summer, two rules set aside

EPA Victoria has granted Viva Energy Refining a temporary exemption from two parts of the state's Environment Protection Regulations 2021. It covers petrol made at the Geelong refinery in Corio from 1 November 2026 to 31 March 2027, which is exactly the window the rules call the "summer period". Viva, the company behind the Shell stations you see around the country, says the refinery supplies more than half of Victoria's fuel and about a tenth of Australia's.

The rules themselves are short. Under regulation 152, anyone who refines, imports or blends petrol for use in Victoria must keep petrol without ethanol to a monthly average vapour pressure of 62 kPa over summer, and no single batch can go above 64 kPa. Vapour pressure measures how readily petrol turns into vapour. It's tested at 37.8°C, a figure inherited from the American test method's 100°F. The higher the number, the more of your fuel escapes into the air.

The exemption covers both of those limits. It doesn't touch the separate 71 kPa ceiling for ethanol blends, so the summer rule for E10 still applies as normal.

EPA's reasons, published on its incident page, are fairly plain. The April fire damaged equipment Viva needs to make petrol to summer specification, so complying wasn't practicable. After what it described as a scientific assessment, the regulator judged the risk to health and the environment to be low. And, tellingly, it found the exemption would mean less flaring at the refinery. The only condition listed is that Viva must meet its general environmental duty at all times.

Why a fire means more volatile petrol

Here's the backstory. Late on 15 April a fire broke out in the refinery's alkylation unit and burned for about 13 hours. Nobody was hurt. Early findings pointed to a failed section of piping.

An alkylation unit sounds obscure, but it does a vital job. It takes the light gases left over from refining, the LPG and butane end of the barrel, and combines them into alkylate, a blending component with high octane and low vapour pressure. Put simply, it's close to the perfect ingredient for summer petrol.

Without it, those light gases have to go somewhere. Some can be stirred into the petrol, which lifts its vapour pressure. The rest gets burnt off at the flare. That's why EPA links the exemption to less flaring: letting more butane into Geelong's petrol means burning less of it in the sky above Norlane and Corio.

Viva restarted its big catalytic cracking unit in June, bringing the refinery back above 90% of normal output. The alkylation unit is another matter. Viva has said it expects to run without it right through 2027 while it decides whether to repair or replace it. That timeline reaches into next summer's period as well, so don't be surprised if this question comes up again.

Haven't we been here before?

Sort of. In October 2020, EPA Victoria allowed Mobil's Altona refinery, just around the bay, to handle a surplus of butane differently after a supply chain problem left too much of it on site. Some of that butane went into the company's petrol. Altona stopped refining the following year.

That closure points to the bigger picture. Australia once ran eight oil refineries. Now there are two, Geelong and Ampol's plant at Lytton in Brisbane. When one unit at one of those two plants breaks, the effects ripple all the way through to the rule book.

Victoria isn't alone in having a summer recipe, either. Perth uses identical numbers, 62 kPa on average and 64 kPa maximum, with 71 kPa for ethanol blends, though its season runs from 15 October to 15 April. Sydney and the rest of the NSW Greater Metropolitan Area have their own petrol volatility limits from 1 November to 31 March. In the United States, the standard federal summer limit is 9.0 psi, which works out to about 62 kPa. Same number, different units.

Bending these rules has been something of a theme in 2026. By August, the US Environmental Protection Agency was waiving its federal summer low volatility petrol standards nationwide, citing the supply shock from the Middle East. Closer to home, Energy Minister Chris Bowen loosened the national sulphur limit for petrol in March, from 10 parts per million to 50, then extended the easing in April. CarExpert reported in May that the limit steps down to 40 ppm for the last three months of this year and returns to 10 ppm on 1 January 2027.

What this means at the bowser

For most drivers, nothing you'll notice.

Modern cars have sealed fuel systems with a charcoal canister that captures vapour from the tank, and they cope with more volatile petrol without fuss. Worth remembering: outside the summer period, Victoria sets no vapour pressure limit at all, so your car already runs on livelier fuel for seven months of the year. Owners of older carburettor cars, classic motorbikes and small engines like mowers can find more volatile fuel harder to restart on a scorching afternoon, so keep that in mind if a heatwave rolls in.

Your choice of fuel doesn't change much either. The exemption applies to petrol without ethanol, which means regular unleaded and premium grades like 98, and only to what's made at Geelong. Imported petrol still has to meet the 62 kPa limit, because importers count as regulated producers under the same regulation. You can't tell at the pump which barrel your fuel came from, and there's no need to try.

On price, think of this as a supply measure. If Viva couldn't legally sell summer petrol made without its alkylation unit, it would have to make less of it, and Victoria would lean harder on imported cargoes in a year when shipping has been anything but reliable. Viva chief executive Scott Wyatt said in April that the costs of the fire would be absorbed by the refinery rather than passed on to the community.

What actually moves your price is still the international benchmark. The ACCC's weekly monitoring put the average petrol price across the five largest cities at 232.7 cents a litre on 4 November, down 1.1 cents on the week, while Singapore's Mogas 95 benchmark fell about 10 cents a litre to roughly 115 cents. Melbourne's discount cycle will matter far more to your next fill than anything happening at Corio, so check the best time to fill up before you head to the servo.

On smog, EPA rates the risk as low. Still, the summer rule exists for a reason, and two small habits help whatever is in the tank: stop filling at the first click of the nozzle rather than squeezing in a few more cents, and make sure the fuel cap clicks shut. Both keep petrol vapour where it belongs.

The short version