| We tested a common additive, Torco, to see if | | | | application. The desired burn rate in a Kart |
| it could add performance to your vehicle or | | | | at 16,000 RPM is very different than the |
| increase mileage. Before discussing this | | | | target burn rate of something like a |
| product, lets first address key differences | | | | big-block V8 at 9,000 RPM. Too fast of a burn |
| between a racing fuel and pump fuel. The one | | | | and you may experience less than optimum |
| everyone thinks of is octane. Under the US | | | | power. Too slow and your valves may be |
| octane rating system AKI (Anti-Knock Index) | | | | opening before maximum pressure is reached. |
| pump fuel is graded as (RON+MON)/2. Meaning | | | | |
| if a fuel had a RON (Research Octane Number) | | | | Without going into further detail such as |
| of 96, and a MON ( Motor Octane Number) of 90 | | | | specific gravity, dielectric constant, and |
| its AKI would be 93. Race fuels can be graded | | | | numerous other variables, you should now have |
| on any of the standards AKI, MON, RON. So | | | | a basic understanding that there is a lot |
| what is octane and why is it important for | | | | more to fuel than just octane. Altering these |
| performance? Octane is what gives gasoline | | | | variables randomly can serve to be counter |
| its ability to resist pre-ignition. As | | | | productive. For the purpose of objectivity |
| displacement, compression, boost, RPM, go up | | | | lets look at one of the most common |
| it becomes harder to keep the fuel mixture | | | | indicators. Octane. |
| from igniting prematurely. | | | | |
| | | | Torco advertises that it can raise 93 pump to |
| If under load or high heat, you experience | | | | 107 when used in the highest concentrations. |
| knock with 87 octane, stepping up to 91 | | | | Tested in the highest recommended mixture we |
| octane is logical step for both performance | | | | saw an AKI of ~99 though a secondary testing |
| and longevity. If you experience no knock or | | | | method. 8 full points from 107 if you assume |
| timing pull at 91 there is no benefit to you | | | | Torco was implying 107 AKI and not 107 RON. |
| stepping up to 93 or higher. Raising the | | | | This would mean it was raising 97RON to 107 |
| octane further would only serve to decrease | | | | RON. If you standardize the results on AKI |
| mileage. The additives that raise octane have | | | | you will see that 107RON is actually fairly |
| less energy than the base fuel, effectively | | | | close to 99AKI. This is much better than you |
| lowering the BTUs of the fuel. That is you | | | | could hope for with the more common additives |
| will make the most power and have the best | | | | such as with xylene or Tulene. If you assume |
| fuel economy with the lowest octane that is | | | | $3.00 per gallon of 93AKI pump and $17.50 for |
| capable of preventing knock under your | | | | a can of the Accelerator that works out to |
| specific conditions. | | | | $6.50 a gallon. With race fuel such as VP and |
| | | | Sunoco in the $5.00 neighborhood this does |
| Another major distinction between race and | | | | not make since. On the other end if the |
| pump fuel is RVP (Reid Vapor Pressure). The | | | | spectrum, you could mix 1 can with 20 |
| easiest, overly simplified, way to think of | | | | gallons. In areas where only 91AKI is |
| RVP is as a system to rate the tendency for | | | | available, this makes a little more sense at |
| the fuel to want to evaporate. The lower the | | | | ~$3.80 per gallon to end up with 93AKI. |
| number the less tendency the fuel has to | | | | |
| evaporate. In general racing fuels have a | | | | So an additives replace race fuel? No. Do |
| much lower RVP than would be found in pump | | | | they have limited applications? Absolutely. |
| fuel due to the poor starting characteristics | | | | If you have a legitimate need for slightly |
| that come along with low RVP fuels. | | | | more octane this is a great way to go. If you |
| | | | are tuning a highly modified engine for |
| Burn -speed is another major difference. Race | | | | maximum power stick to race fuels. |
| fuels are blended towards a specific | | | | |