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Has the AA ever done tests on the fuel from BP compares to other suppliers?

I have noticed on my motorbike that if I use BP 91 octane fuel that I struggle to get 300km out of my 18l tank. However if I use other fuel, particularly Caltex, I can usually get to 350km.

That's 5.666 l/100km on BP versus 4.88 l per 100km on Caltex which is quite a difference (based on 17l used as obviously I never run the tank dry).

Usage is for commuting only, so the conditions applied were very much the same.

A few years ago we carried out tests for the Fair Go TV programme comparing fuel consumption results using petrol from two different suppliers.

In this case we went to great lengths to ensure the tests were as accurate as possible without getting into specific laboratory or scientific testing. We used the same car, driver and route which finished on the Meremere drag strip south of Auckland. This was a controlled environment as the car was driven in each run until it completely ran out of fuel.

To further enhanced the credibility of the test, we removed the fuel tank from the car before the first run and completely drained it. It was then refitted and refilled with a measured amount of fuel. After the first run was completed, the car was towed back to our makeshift workshop, the fuel tank removed again and another completely drained fuel tank (from the exact same model vehicle) fitted and the test repeated.

In the big wash up, the results were too close to declare a clear consumer advantage for one fuel brand over another.

There are always winners and losers when this sort of testing is undertaken but when you take into account driver consistency, air temperature differences etc the results were almost identical.

I’m not suggesting you carry out similar tests but I would encourage you to carry out testing over an identical route and riding style and see if the results are any different.

From fuel testing we have done for various new vehicles distributors in NZ and during the biannual AA Energy Wise Rally, we know how critical it is to start with a full tank of fuel and refill to the identical level.

Love to know the results of any further tests you may carry out.

The AA is currently planning to carry out fuel testing on the advantages (or not) of using the different petrol octane’s available including the ethanol blended fuels.

I wonder whether it might be car specific as to which brand of fuel gives better economy and performs better.

My brother has a 1996 Honda Civic and changed from BP 91 to Caltex 91 and recorded significantly better fuel economy and performance with Caltex 91. After his experience I bought Caltex 91 for my wife's 1994 Toyota Corolla from the same Caltex station. What I experienced was a significant increase in fuel consumption and gutless performance and returned back to BP91.

I also tried Caltex 95 in my 1997 Honda Accord and also noted a degradation in power and economy and went back to using Shell 95.

It is unlikely you would experience different fuel economy from different brands as fuel sold in NZ must meet stringent standards and although different fuel companies may add some additives these would not effect economy but some are said to improve performance.

With half of all petrol sold in NZ refined at Marsden Point it is the same fuel anyway regardless of brand, and the remaining half is often sourced from the same international refineries. The only exception is Gull petrol which is blended with ethanol,which has a lower energy content, so you could expect a slight difference in economy if using Gull.

The difference in economy is likely due to variations in driving style, traffic conditions and distance travelled, but it is also possible that the amount you fill up with each time is slightly different due to foaming or ambient temperature in the tank although this should be negligible. Fuel quality, and fuel bowser accuracy, are randomly tested by the Ministry of Economic Development, funded from a small tax levied on fuel to ensure it meets the standard.

As I said the bike is used to commute 24 km each way to and from work. I leave at the same time every day, the route never varies and since I lane-split the driving style is very very even. I do not use it for weekend rides. The reason I noticed was that I used to fill with BP to get AA points but I could not spend enough in one tank fill to get any points so I decided to use the self-serve Caltex on Hutt Rd since it used to have a 2c discount off other stations and it was conveniently on the way.

I will run 2 tanks through of Caltex (since that is what I have at the moment) and then 2 tanks of BP. That should be enough to know for sure. A tank lasts 6 commuting days so the whole exercise will take a month. I will post the result regardless, even if it makes me look like an egg.

Also have to wait until my speedo is fixed as the magnetic rotor has failed and I have to get another imported so it'll be well into August before I have a result.