Is anybody out there using Premium gas in their RCS140 or should I stick with Regular? Does it really matter? Why? Or maybe strike a happy medium with Plus?

thanx

Have heard it said time and time again that we derive no additional benefit by using anything other than regular 87 octane, unless specifically advised otherwise by the engine makers.

Why not just use what they recommend in your manual.

Karol

Just had a look in the RCS 140 manual, it recommends the use of PREMIUM gas mixed at 50:1.

Karol

Run the regular. There is absolutely no benefit from the higher octane ratings unless you have higher compression ratios demanding a slower burn rate. Like over 9 to 1.

A friend of mine just received the new version of this engine which has the Falkon ignition. It too has conflicting documentation. One paper lists premium and the other says regular. For myself, it is a matter of convenience since I have RCS and ZDZ engines. The ZDZ says premium throughout. It would be much easier to carry one type of fuel supply. As for my friend, this is his first gasser so he is trying to ensure he has everything correct from the beginning.

If you engine is knocking (pre-detonating), then go to higher octane. If not, stay at regular. All octane does is supress the burn rate of the fuel, so that engines can run at higher compressions without pre-detonating the fuel.

I have emailed ZDZ directly and they told me that they do not recommend premium gas. The octane rating they recommend in their manual is based on the European method of rating octane....which I think they use the research octane number. In the US we use an average of the research octane number (RON) and the motor octane number (MON) so when its all said and done in the US you only need 87 octane for the ZDZ's...I imagine the RCS is the same way.