OPINION The competition watchdog's market study into the $10 billion fuel industry ran on angry fumes and ended in a splutter and stall.

Commerce Minister Kris Faafoi has forecast that the price of petrol could fall about 18 cents a litre in areas that aren't already benefitting from strong competition, as a result of recommendations made by the Commerce Commission.

But, in my view, that is highly speculative.

Commission chairman Anna Rawlings was herself certainly making no such specific claims, when the results of its year-long probe into the fuel market were released on Thursday.

Petrol companies will be required to display the price of 95 and 98 octane fuels, which make up 23 per cent of petrol sales, on their roadside boards.

The commission found petrol companies were charging a growing and unexplainably high price premium for those fuels.

Sure, that change is no bad thing.

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But petrol companies already display the price of 91 on their roadside boards and that doesn't appear to have stopped them charging vastly different prices for fuel around the country.

Having to display a price doesn't in itself ensure a price needs to be competitive.

The same might be said of the commission's "major" recommendation, which is to require the fuel majors BP, Z and Mobil advertise a spot price at which they would sell fuel to "independent" retailers at their fuel terminals.

Independent retailers already source their fuel from the majors.

But the commission's hope is that an advertised spot price, or "terminal gate price", at which a retailer could (subject to some caveats) just roll-up and buy fuel would assist in making the wholesale market more honest.

To be clear, BP, Z and Mobil would be free to set their own spot prices as they wanted, and change that price without notice on a daily basis.

At least initially, their terminal gate prices would not be regulated and – as with the fuel prices displayed to consumers on roadside boards – there would be no immediate onus on them to prove those prices did not build-in high profits.

Unsurprisingly, experience in Australia has shown that it is not viable for independent petrol retailers to buy much of their fuel on a spot market in such circumstances.

Even if the fuel majors did offer broadly competitive terminal gate pricing, independent retailers will generally need the surety of price and supply that comes with a long-term supply contract.

As the Commerce Commission I think makes pretty clear in its report, the main benefit of terminal gate pricing is that it could help shine more of a light on wholesale pricing and support additional interventions down the track by the regulator.

It is not, in and of itself, a solution to excessive profits in the industry and, as the commission notes, it comes with real risks.

These include the danger that terminal gate prices might backfire by making it easier for the fuel majors to "coordinate" their wholesale pricing.

The fact that Z and Mobil supported the introduction of terminal gate pricing, and that BP was fairly phlegmatic about it, will probably tell motorists most of what they need to know.

There are a few other potentially useful bits and pieces among the commission's recommendations.

It has recommended weakening the major fuel companies' ability to cajole independent retailers into exclusive long-term fuel-supply contracts, by giving them the automatic right to shop around for perhaps 20 per cent of their fuel.

But it is small beer, really.

I believe the commission has missed a couple of opportunities.

Its market study may be 589 pages long, but that doesn't mean it covers all the options.

If there is any reference at all to the risks of "predatory pricing", then I can't find it.

In my view, one way to ensure the petrol majors play fairly would be for the commission to fully audit a couple of individual service stations each year in areas where they have dropped their prices.

That would be to ensure the petrol majors were not pricing below cost in some locations where they faced competition, in an attempt to restrict the broader growth of independent chains.

The report also appears to omit any reference to the dangers associated with "price signalling" by the petrol majors.

That is even though the rise in petrol company profits that concerned the commission appeared to partially coincide with Z Energy expressing the view, when it entered the market in 2010, that margins in the industry were too low and needed to increase.

Hope may not be lost for motorists.

Ironically, as the commission notes, there is some evidence that profit margins on fuel may be on the decline anyway.

Chains such as Waitomo have been able to expand their operations without the commission's help, and the overall demand for petrol appears to have past its peak.

As the decline in petrol sales picks up pace – driven by more fuel efficient-cars and the needed switch to electric vehicles – it should become harder for large retailers to hold a strong line on margins.

Also, while fuel discount and loyalty schemes have in the past worked against consumers overall, the recent trend for the big chains to privately offer more individually-tailored discounts to motorists via apps and email would appear to make price coordination at the retail level increasingly difficult.

So motorists may get a better deal, no thanks to the Government or the competition watchdog.

The market study was the first conducted by the Commerce Commission under a new regulatory regime that gives it more powers to demand information from private companies.

Building products may be next up for investigation, given concerns that prices for the materials needed to build houses can frequently be up to 30 per cent more expensive than in Australia.

The supermarket "duopoly" is another possible target for scrutiny.

But it makes sense for the commission and the Government to be honest about the outcome of the fuel market study, and any lessons to be learnt, before they consider what markets they should tackle next.

One question they may want to ask is whether they already have the tools in their toolbox to deal with issues in front of them, before building up expectations too high and being dazzled by their shiny-new market-study powers.