Fuel choice for 582

[Guest sypkens]

Hi,

 

When i started flying I was advised to use unleaded fuel for the 582 engine. I think at the time I was told that Premium would foul the plugs. I have only ever used Shell unleaded. I have recently started using premium in my mower and have seen remarkable differences in the performance of the mower which has gotten me thinking about my choice of fuels.

 

My question is to other members what do they use in their 582's and if they are using premium have they encountered any issues?

 

Thanks

 

Jan

 

 

[Dieselten]

98 Octane unleaded solely. It has more megajoules per unit of mass (pound, kilo, tonne etc) than other fuels and I have had no issues at all. Shell V-Power, BP Ultimate (preferred) or Vortex 98 are all good. They contain no ethanol or methanol, or MTBE or ETBE for that matter (i. e. methyl tertiary butyl ether or ethyl tertiary butyl ether, also used to bump octane-ratings). Remember, we really should be buying fuel in units of mass instead of volume because the density of fuel varies with temperature whereas one unit of mass of a given fuel contains a fixed number of megajoules and it is megajoules which propel us via combustion-energy imparting a rotary motion to propellers.

 

DO NOT USE 100-octane unleaded, or any unleaded with an octane-rating below 95! The additional octane rating is achieved by the addition of alcohol. Ethanol and methanol are not good for your 582. Lower octane fuels are now being adulterated with ethanol or methanol as well. When in doubt, test the fuel with a fuel-alcohol tester available at pilot-shops or motor-mower stores (a Briggs & Stratton fuel-tester from a motor-mower shop costs about $50 and will last forever with care)

 

Look carefully at the fuel-bowser when you buy fuel! Any fuel containing alcohol must be marked on the bowser by law. Read the fine print...the fuel companies don't want you to know what you are putting in your tank.

 

AVGAS 100LL is also not recommended for the 582. It will work but you will get accelerated upper-cylinder wear and rapid lead-fouling of your spark-plugs.

 

98-octane unleaded exclusively is the best 582 fuel in my experience.

 

 

[Arnaud]

Welcome to the 21st century reality: you have now to pay a premium to obtain what was standard quality in the past and the standard product of the day is rubbish.

 

I am in the food business and there too this rule applies.

 

Do not rely on laws to guarantee that you get what you thought you paid for as there are very few people available to enforce them; it is all "self regulation" nowadays.

 

Ask your fuel retailer if there is alcohol in the fuel he sells you and see the look on his face ! The smarter ones will tell you what YOU want to hear.

 

There is an interesting article on Fuel Life at www.kedronmowers.com.au

 

Arnaud

 

 

[Smokey]

Jan

 

My 2 bits worth.

 

I use BP Ultimate, no particularr reason for brand choice but I always get it from the same servo and have never had a problem with quality, I cannot say the same for two other servos I've tried, one each from the supermarket chains. Fortunately the bad fuel I got from those was only in the car not the plane. I run the same fuel in my car as in the plane, any hiccups and none of that fuel goes in the plane.

 

I also had a specific problem with Shell Ultimate where a bit was spilt onto the wing, the additives they had in it lifted the paint, I don't know if Ultimate's replacement, V-Power, has the same problem, I haven't tried it.

 

From what I've read the octane rating also deteriorates in storage so, if you buy standard which I think is 92 octane and you store it for any length of time, you may find that the octane rating has dropped close to or below the minimum 90 octane specified by Rotax. Also, there are different octanes, research octane (light load test), motor octane (heavy load test) both comparitive measurements which have accuracy limited by experimental considerations and road octane number which is an average of the 2, so depending on which octane is used to specify the fuel you are using you may be using fuel which has a larger or smaller margin above the 90 octane minimum specified by Rotax, assuming that it is above the minimum.

 

I believe in Australia the standard is the research octane number while the US uses road octane number, I don't what Europe uses or what Rotax quotes. The trouble here is not knowing what standard Rotax uses and what measurement accuracy the oil companies work to and don't forget you also have marketing departments here telling people what to say.

 

I imagine this is the reason some people say you should not use anything below 95 octane, gives you a bit of a buffer.

 

Sydney Recreational Flying Club has been using Rotax 2 stokes for over 20 years and has accumulated a lot of knowledge on them, the clubs aircraft and to my knowledge all the members who have a 2 strokes all use premium with no problems relating to the fuel.

 

Mark