Fuel claims driven by ‘voodoo’

Are new types of petrol actually good for your car? By John Anthony.

CONSUMERS are being left in the dark about whether slick, new petrol formulas are worth the money, experts say.

Fuel giant Mobil has released a reformulated range of petrol products dubbed ‘‘synergy fuels’’ containing ‘‘new and improved’’ additives, and claims the mixes can reduce vehicle emissions and improve fuel economy, engine responsiveness and performance.

BP also said its Unleaded 95 is a ‘‘special blend’’ designed to bring a knock-free performance to unleaded cars with a high-octane requirement.

Meanwhile Z Energy’s premium fuel ZX features a ‘‘friction modifier’’ and cleaning additive, its website said, and Caltex 95 Techron is said to clean engine parts.

But this week, University of Auckland school of chemical sciences senior lecturer Duncan McGillivray said if the additives were unknown, it was difficult to assess the validity of the claims.

Mobil and BP would not share their list of additives on the grounds of commercial sensitivity. Caltex did not give details of the additives it uses, and Z Energy did not respond to questions by the time of going to press.

‘‘It’s impossible to judge whether there’s value in this,’’ McGillivray said.

‘‘Because engines are so finely tuned, having good-quality petrol really does make a difference.’’

But any difference would be subtle, he said. ‘‘Most of it is probably about feel-good factor.’’

Some of the additives used in petrol were basically soaps which could help an engine run more smoothly. ‘‘It will do good things for your car, but it’s just so hard to put a price on what that is worth.’’

Automobile Association petrol watch spokesman Mark Stockdale said high-octane fuels did have marginally higher energy levels than lower grades, so fuel economy may improve. But past tests by the association indicated motorists received little or no financial gain by using 95 octane in a car configured to run on 91, despite an improvement in economy.

About 80 per cent of all petrol sold in New Zealand was 91 octane. The rest was 95 or 98, Stockdale said. Premium 95 generally costs 9 cents a litre more than 91 and premium 98 costs another 8c on top of 95.

The AAA Foundation for Traffic Safety released findings this week showing United States motorists wasted $2.1 billion in 2015 buying premium fuel for cars that do not require it.

Marketing expert and managing director of Evolve Marketing, Brandon Wilcox, said fuel companies were failing their customers by not disclosing what additives were used. ‘‘From a marketing perspective it’s absolutely imperative to disclose what’s in there because at the moment it’s just some kind of voodoo.’’