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Ethanol & Flex Fuel Tuning: Pump E85 Vs Commercial E85

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Pump E85 Vs Commercial E85


00:00 - When it comes to E85 you may have the option of pump E85 depending on your location.
00:05 Or purchasing a commercially available E85 from a race fuel manufacturer such as VP Racing Fuels or Sunoco for example.
00:14 These commercial E85 blends are usually substantially more expensive than pump E85 but it's worth understanding the pros and cons of each.
00:23 As we've already discussed, the actual ethanol content of pump E85 can vary dramatically based on the season and ambient temperature.
00:32 Just as importantly though, the products used to make up the gasoline element of the ethanol blend may also not strictly be the gasoline that we would normally be filling our car up with.
00:43 The specification for the gasoline component dictates that it must be made from unleaded gasoline, gasoline blend stocks for oxygenated blending, natural gasoline, or other hydrocarbons in the gasoline boiling range.
00:58 Now this probably doesn't mean much to anyone outside of the petroleum industry, however the important point is that there is no specification for the actual octane of the gasoline component.
01:10 This means that the 15% gasoline component may be a much lower octane rating than what you'd typically see at the pump, and of course this can have an effect on the overall knock resistance of the fuel.
01:23 This gets even worse when we start considering those lower ethanol blends used in winter where this potentially may make up almost half of the fuel volume.
01:33 The result is that for those who are relying on the knock resistance of ethanol to safeguard a highly tuned, high boost engine, pump E85 can be variable at best.
01:45 If you want a fuel with a guaranteed consistency and octane rating, commercially blended E85 may be worth considering.
01:53 This is a common choice for those who are running a dedicated race car as the actual fuel consumption is understandably lower than what we could expect for a daily driven road car, and hence the additional cost is mitigated slightly.
02:08 Commercially blended E85 from a race fuel manufacturer, will have the advantage of a consistent and guaranteed ethanol content, so you can be certain that the tune will remain consistent.
02:20 Beyond that though these fuels will also typically incorporate a higher octane unleaded fuel to make up the gasoline component, hence raising the overall octane rating of the fuel.
02:32 This makes these fuels better suited to those who are really pushing the limits of engine performance, and need all of that knock resistance that they can achieve.
02:41 Commercial E85 blends may also contain other additives such as corrosion inhibitors to help prevent or reduce some of the common corrosion problems that ethanol is known for.
02:53 Some commercial E85 blends however may also contain the additive MTBE, which is known to be incompatible with some of the larger aftermarket injectors that are originally designed to operate with compressed natural gas.
03:07 So care is needed to ensure compatibility with your fuel system.
03:12 Independent testing has also shown that some of these E85 race fuels can produce more power that pump E85, so this needs to be factored into your decision too.
03:23 VP for example claim that their C85 product can increase power by 4% over a typical pump E85, while independent testing has shown this claim to be in fact conservative, with the results showing an improvement closer to 8%.