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Does Super Unleaded offer any performance gains?

Petrol is petrol, right?

Well depending on whom you ask, the answer could be yes… or no!

According to people working at refineries, most fuel you buy from the pump comes from the same few refineries, and it all has to meet certain standards. So they argue the same grade of fuel is likely to be identical regardless of where you filled up.

On the other hand, other people suggest that whilst the base fuel will be identical, the blends of additives will not, so that a chemical analysis of fuels from different sources will show they are not in fact identical. And they point to independant tests on vehicles where different power output result as evidence.

Naturally, the big name fuel manufactuers are keen to suggest that their own fuels work best, and they have been using this form of advertising for years – remember the “tiger in your tank”?

And one way they attempt to differentiate themselves in a market in which it is peculiarly difficult to stand out is to sell their ‘super fuels’ that have a higher research octane number (RON) than the regular brew.

So what are the benefits of these 98, 99 and even 102 RON fuels over the standard 95 octane pump fuel?

The usual marketing claims are that these fuels increase power, result in less pollution and help to keep the engine internals cleaner.

But is that a fact?

It’s really hard to say. One group argues that higher octane fuel is just a waste of money, because virtually no modern engines actually require 98 RON fuel. They tend to argue that filling up with ‘more powerful’ fuel simply leads to the “placebo effect” – there’s no change but drivers think their engine is running better!

On the other hand, it’s worth pointing out that most tests are done on cars, and if you don’t count the performance models, cars are usually in a lower state of tune than a motorcycle. Independant tests often show that there are measurable gains to be had when the different fuels are run in a test vehicle. Bike Magazine ran a test some years ago, and there was a marked difference in power output of a motorcycle run on different forecourt fuels, with supermarket petrol providing poorer mpg and performance.

And most recently bikes like the new K1200R can sense knock and adjust their engine tuning to take advantage of higher grade fuels.

So the final question is to ask if any benefit outweights the extra cost involved in filling up.

Until recently, I would have said “no”.

However, as the price of fuel has climbed, the differential between “cooking” unleaded and the full-fat stuff has reduced – it’s often only 3 or 4 pence a litre more than the regular fuel, which is only around 3-4% difference.

So over the last year, I’ve started pouring it into the Hornet to see what happens.

Now, I’m the first to shout “snake oil” when I see fuel and oil additives, the like of which are claimed to boost performance, but I have seen the fuel economy of some of my bikes that I have had for quite a few years drop quite dramatically through the 90s when “combustion modifiers” started being added to pump petrol in quantity, so I’m aware that what you pour into the tank does make a difference!

What are my impressions of running on super unleaded?

Well, I know it’s ‘seat of the pant dyno’ and hardly objective but the high mileage engine in the Hornet is getting a little tired and on the super unleaded fuels it definitely seems to pick up more cleanly just off idle and runs a little more smoothly at mid-revs. It was particularly noticable on a cold morning just recently when I filled up with ordinary 95 RON fuel from a forecourt locally, and the motor stuttered quite badly. A tank of super unleaded improved it immediately. It seems to start better from cold on a really chilly morning too.

But to me the clincher is that the fuel consumption has demonstrably improved.

Not dramatically, but sufficient to be noticable particularly as the range of the Hornet is particularly limited by the small tank. An extra 10 miles or so out of a typical full-to-reserve tankful is quite obvious, and that equates to around 3 or 4% more miles per gallon.

So am I any nearer an answer to the original question?

Well, reading online articles suggests the internet jury is still out, and whilst the 3-4 mpg extra on top of the low 50s that the Hornet already gives isn’t that dramatic, and it doesn’t really save any money, the 10 miles extra range in the notoriously small tank is surprisingly useful.

So I’d suggest you try it. It certainly won’t hurt – and it just might help!

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