Yes and No…How’s that answer for ya?
We first of all need to separate out the discussion on race gas between 50cc auto engines and 65cc multi-speed engines. Both behave very differently with respect to fuel variations, and since the 50cc auto engine is the more finicky of the two, most of this conversation will focus on it.
Here is the issue: The vast majority of the time, putting race gas in your 50cc engine will harm rather than help your situation when using it instead of a good 93 octane pump gas. Note the emphasis on the word good…Many pump gasses are anything but good. Nearly all contain components other than gasoline, and much of the time this is due to federal and local laws mandating ‘clean’ fuels for various times of the year (i.e. summer gas vs. winter gas). So…Filling up in June vs. filling up in November – even from the same gas station – can result in a very different product in your gas can. As a result, this can lead to variations in performance, jetting requirements, and tolerance to engine damaging detonation.
Furthermore, there have been several investigative journalism pieces lately on the quality of pump gas, and the results were downright scary. Dateline NBC, for example, found pump gas as low as 75 octane! The show tested 85 different samples of ‘name brand’ premium gasoline purchased in California, and out of that group there were 11 that tested below the octane posted on the pump.
Car and Driver magazine followed up by reporting that in Michigan, the Bureau of Weights and Measures failed 217 of 2816 samples of ‘high test’ pump gas because of low octane. It also has been reported that 15% of the gasoline in New York State is substandard.
Bottom line: what you get from the pump varies widely in quality and in chemistry. You are rolling the dice when purchasing race fuel from a corner gas station.
What to do?
Maybe a better question is what not to do…
1) Don’t purchase fuel on the road if you can help it. Chances are the local laws (i.e. how much ethanol must be mixed with gasoline) are different that what you are used to, and as shown above, the quality of fuel can be a crapshoot.
2) Don’t bother with ‘octane enhancers’. None of our testing has ever shown these additives to do anything.
3) Don’t blindly purchase race fuel and think your bike will run better…Many times (especially a 50cc auto), it won’t.
4) Don’t be too aggressive in running advanced spark timing (>0.040” on a Cobra 50cc auto). This will only make your engine more sensitive to detonation, and the combination of advanced spark timing and poor quality gasoline can melt down an engine quickly. For more information on how to set spark timing, see your manual.
Some tips:
1) For 65cc and larger bikes, purchase race fuel and use at least a 50:50 blend with high test pump gas from a local, trusted fuel retailer. VP U4-2 is a good example of a fuel that keeps engines free of detonation and improves overall power output.
2) For 50cc bikes, we still recommend 93 octane gasoline without any ethanol added. This is not easy to find these days, however, there are some tools to help you navigate which retailers to use and which ones to stay away from. First of all, it needs to be noted that not all states mandate Ethanol labeling at the pump. For a comprehensive list of states check here. Secondly, if you really want to know you are getting pure gasoline, then you need to purchase a tester. They are not expensive (about $30), and they can come in handy if you are on the road and need to find fuel. Here’s an example of a fuel tester you can purchase online.
3) Be prepared to chase jetting with race fuel. The vast majority of race fuels are more sensitive to changes in atmospheric conditions than pump gas. This means that the jetting that worked in morning practice may be way off by the time your afternoon moto rolls around.
4) Don’t believe the hype. Unless you see hard data that a fuel or additive works, don’t trust it. Moreover, NEVER try a fuel at a big race for the first time (yea, I know…You need every advantage you can get). Unless you have tested, raced, and tested some more, stick with what you know.
Lessons for the day: 1) be careful…Variations in fuel quality and chemistry are big. 2) Know what you are putting in your tank, 3) Don’t jump at magic bullet solutions for race gas or additives…The vast majority of the time you will go backward and in the worst case do a lot of expensive damage to your engine.
See you at the races…
Sean @ Cobra
Palmer Kling visited the International Powersports Dealer Expo last weekend in Indianapolis, IN. Palmer was there to visit his sponsors and check out all the cool new products available. It was an exciting trip with lots to do and too much to see. The show was packed with every imaginable motorcycle product and industry representative.
