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Does premium fuel give bikes a boost?

Fuel economy service station helmet pulp ulp premium

Using a premium fuel with a higher octane than specified by the motorcycle manufacturer will not improve engine power or economy, RACQ technical officer Steve Spalding advises.

He says the energy content of fuel is the same no matter what octane rating it has.

“We see a lot of claims made about using premium fuels over standard and often motorists/riders believe they get a benefit from their use,” he says.

“The reality is by using a fuel with a higher octane than specified, there is only an economic or performance benefit if the engine management system can utilise the higher octane. Some will and others won’t.”

The anecdotal evidence of riders saying they get more power and higher range from a higher octane than their bike needs may simply be justifying to themselves the extra expense of PULP, Steve suggests.

Steve Spalding DIY bike maintenance Easter safety message duty easter pulp ulp premium
Steve Spalding

Premium advantages

However, there are other advantages to using a PULP fuel over ULP.

“Some premium fuels such as Caltex and BP advertise they have additional cleaning additive packages that can offset the need to periodically buy fuel cleaners,” Steve says.

However, riders would have to work out if it is cheaper to pay the extra price for PULP over ULP rather than buying the occasional cleaner additive.

It may have been an economically wise decision about a decade ago, but the price differential between ULP and PUP has crept up and is now about 12-14c a litre.

“Fuel makers have worked out that people will buy it, not often on an evidence-based reason,” Steve says.

Steve says fuel companies and retailers make the most profit from the sale price of PULP.Fuel petrol servo service station helmet pulp ulp premium

Steve also points out that while ULP also has cleaning additives, it just doesn’t have the additional cleaners in some of the higher octane fuels.

However, it is certainly more convenient to have the cleaner additives in the fuel than having to periodically buy and add the fluid separately.

Steve also says PULP has lower levels of sulphur.

“While these are beneficial in reducing the build-up of engine internal deposits, they won’t make the bike travel further for each litre of fuel purchased,” he says.

“The best advice is to use the fuel specified for the bike.”

Low octane risksDirty fuel premium

Most modern motorcycles recommend a minimum of 95 or 98 RON.

If you fill up with a lower octane rating you run the risk of harmful engine detonation and pinging, Steve warns.

Also the higher sulphur content in RULP can damage catalytic converters and prevent them from working properly.

Some motorcycles have knock sensors that sense detonation or pinging and alter the ignition timing to effetely down-tune the engine.

Knock sensors are a preservation measure in case you are stuck at a remote service station that doesn’t have premium fuel.

Lastly, with E10 being common in services stations, ensure your bike is compatible with it before using, older carburettor models shouldn’t use an ethanol-based fuel.

Click here for more advice on using ethanol fuel in motorcycles.

  1. My Street Triple R requires 91ron minimum. I’ve always used 91RON, and when testing 95/98 over multiple tanks, there is no additional benefit except the gas stations make more money.

    I don’t get any additional mileage, and the bike actually feels more sluggish on 98RON. I’ll stick to what the recommendations are based on the R&D by the manufacturer.

    1. I’ve got a 1050 Tiger Sport. Commented at first service that it seemed rough using 98. I was told that if they have a triple running rough and it has 98 in it the first thing to do is drain the tank. Can’t tell the difference between 91 and 95.

  2. One of my favorite subjects, having worked for a petroleum company and raced motorcycles I have some experience in this matter. Firstly pump gas as you buy it from the gas station will make a small difference, not much. Then you can choose from race gas blends that you buy from a supplier. Finally you can blend a fuel to suit conditions on the day. The best option for a street bike rider is to buy fuel from a modern station that has fresh fuel. There are fuel blends that will make a noticeable difference for a motorcycle in a track day situation. A lot depends on the air temperature, a cold low humidity day will show a 4 to 8 percent improvement in power, fuel only.

  3. Octane rating is roughly a measure of the self ignition temperature of the fuel. In the days of lead petrol the supplier could just add tetra-ethyl-lead to get whatever octane rating they wanted. Now they need to refine the fuel better to get higher octane ratings. Ie a purer standard hydrocarbon rather than a mix of gunk. So lower octane fuels tend to contain more gunky chemicals like toluenes and long chain paraffins because they can. Hence dirtier burning and less efficient combustion. Its not that PULP cleans the engine, rather that RULP dirties it!

    But don’t be confused by Ethanol. Ethanol has a high latent heat, so when it evaporates it cools the mixture and this raises the octane rating. The ethanol allows the supplier to blend the fuel with even poorer quality petrol.

    1. Ethanol is also highly hydroscopic. Regardless of the apparently higher octane rating, I found my ute gets allbut 10% less total distance on a tank compared to normal 91. Wouldn’t put it in a bike. At all. Interestingly, my old GSXR1100 was supposed to use 91, but it ran smoother and felt more responsive if I filled with 98.

      1. There are separate issues here.

        Yes it is hydroscopic. This means that you should never have an ethanol blend in a partly full tank for any peripd of time, as it will absorb the moisture from the available air. Filling from a regularly used petrol station, and keeping your tank full, helps avoid the vast majority of this. The main problem with ethanol fuel beyond this, is its incompatibility with seals and components not designed to be used with ethanol.

        Yes it has a higher octane rating, but (and please correct me of I am wrong) the benefit is in three separate areas. *My* understanding is that the fuel itself is higher octane, period. The benefit of evaporation cooling the intake charge is in addition to the higher octane & not the reason for the higher octane rating. This benefit is greater, the longer the fuel is in suspension. Ethanol fuel also requires a larger fuel volume for a given amount of power and so provides a third level of benefit, this extra fuel itself also having a cooling benefit.

        Touched on above, octane rating has NOTHING to do with fuel economy. Octane is very simply the resistance to detonation. It does not relate to the energy content of fuel. You will always use more of an ethanol fuel as by volume (or weight, I cant recall) it has approximately 30% less energy than gasoline based fuels. So, if youre talking a blend of E10, 10% of the fuel has 30% less energy in it, which using simple maths is a 3% reduction in energy content in E10 fuel vs E0 fuel. When talking about high blends lile E85, the mileage is nearly off by 30%. A vehicle must be tuned properly for an ethanol fuel as a result.

  4. 12 to 14 cents difference? Not in Queensland, more like 20 cents here. Yes it is an enormous rip off that the motoring bodies could address.
    Be nice if the price difference between pulp and ulp was similar at that between e10 and ulp.
    PS I say e10 is overpriced compared to ulp, an other rip off.

  5. You may want to proof-read these statements.
    Also the higher sulphur content in RULP can damage catalytic converters and prevent them from working properly.

    Some motorcycles have knock sensors that sense detonation or pinging and alter the ignition timing to effetely down-tune the engine.

  6. Nobody has mentioned compression ratio. Some modern bike engines run 12 to 1. If a petrol engine with that high a ratio detonated, it would effectively destroy itself.
    Two developments in recent years have avoided that scenario.
    Direct injection avoids detonation because there is no fuel in the cylinder until the moment of ignition.
    Knock sensors retard the timing, (and reduce power) to avoid detonation.
    So with those two factors, you can get away with lower octane. But if your engine does not have either, and many don’t, you may need 98 to avoid deadly detonation.

  7. I was always lead to believe that 98 was a denser fuel and therefore has more energy per liter which should mean a slightly higher range.

    1. RON refers to the amount of compression you can subject the fuel to before it ignites (without a spark). That’s why high compression motors need a higher RON and high compression motors are usually high performance. Hence a lot of people think high RON = higher performance. It’s the other way around, high performance needs high RON

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