Sport Compact spec fuels list is here

Why does VP use Motor Octane Numbers?
Motor octane more accurately represents a high performance or racing application. The motor octane machine runs at a higher RPM, hotter temperature, and more timing, thus putting more stress on the fuel. Do not be fooled by high research or average (R+M/2) octane numbers.

How much Octane do I need?
Only enough to stop preignition and/or detonation. Remember there are other important factors in power output than just octane. Octane is not the measure of the fuel's power output, it is only a measure of its resistance to preignition and detonation in an octane engine.

What is the highest octane rating a gasoline can have?
For research and motor octane ratings the ASTM methods No. D2699-81 for the operation of the octane engine gives a scale up to 120.3.

What type of 2-stroke oil should I use with VP?
All types of oils, petroleum, synthetic blend, synthetic or bean oils will mix with VP. However, bean oils will tend to separate below 35 degrees F in fuels with a specific gravity of less than .730.

Why do plugs with VP gasoline look so lean?
Because the percentage of the aromatic hydrocarbons in the fuel is relatively low compared to other gasolines. These products have soot forming properties in gasoline.

Will an engine run cooler with VP?
Yes, C-12 and C-14 will obsorb more heat than other gasolines and tend to cool the intake charge. This is especially noticeable in 2-stroke applications.

What is the best way to store VP Racing Gasoline?
As long as the gasoline is kept in a tightly sealed container, the storage is indefinite. These gasolines contain olefinic hydrocarbons in negligible concentrations, thus their tendency to form gums and varnishes is negligible. The gasoline will not separate as its components are solvents of each other. Also, don't expose the fuel to direct sunlight as the ultraviolet rays will oxidize the lead.

Is VP Racing Gasoline made the same every time?
Yes, absolutely. For many people this is one of the most important qualities of our fuels. If there are any improvements in the fuel, we will inform you of the differences and what to expect from these differences. We realize fuel is one of the things a racer can't check, so we feel very responsible for quality control.

OCTANE NUMBERS AND WHAT THEY REPRESENT
One of the most frequently asked technical questions we get at VP involves the difference between Motor, Research and R+M/2 Octane Numbers. The next most frequently asked question is why some fuel companies represent their fuels with Motor Octane Numbers, while other companies use Research or R+M/2 Octane Numbers.

To answer these questions, we need to first explain the machines that do the testing. These machines were made in the 1930s and were designed to test for octane numbers from the 0-100 range. Any number above 100 is an extrapolation. Both of these machines are dinosaurs and are not adequate for today's high tech fuels or engines, but they the only means available for testing fuels. These machines are one-cylinder engines that have an adjustable head that can move up or down to increase or lower the compression ratio while the engine is running. The Motor and Research machines are the same in this respect, but they differ in several other characteristics. The following is a comparison of the two machines used for testing octane numbers:

Motor Machine Research Machine
RPM 900 600
INTAKE TEMP. 300 DEGREES F 120 DEGREES F
TIMING VARIABLE BASIC
SETTING 26 DEGREES FIXED AT 13 DEGREES
(DOES NOT CHANGE)

As the comparison above shows, the Motor Octane machine runs at a higher RPM, hotter temperature and more timing. This machine will put more stress on any fuel and more accurately represents a racing engine. VP Racing Fuels always uses Motor Octane Numbers when advertising our fuel because our fuels are used primarily for racing applications. The Research Octane machine will always produce a higher number for the obvious reason that it does not put the same amount of stress on the fuel. This number is used by some fuel companies to trick the racer into thinking he/she is getting a better fuel. The R+M/2 Octane Number is the average of the Research and Motor Octane numbers and is the number displayed with yellow labels on retail level gas pumps.

When comparing fuels for racing purposes make sure to compare Motor Octane Numbers because these are the ones that count in your racing applications.