Some Help with E85 Cold Starts

For many of us who have an ECU reflash product such as OpenFlashTablet (OFT) or Ecutek, it’s fairly easy to get your hands on a tune/map that will allow your BRZ/FR-S to switch over to running on E85 fuel (which consists of 85% ethanol, 15% gasoline) as an alternative to 91 octane gasoline.

Among the benefits of running E85:

  • more power/torque
  • lower cost per gallon than gas
  • higher octane means higher resistance to detonation
  • cleaner burning fuel means less harmful emissions (carbon monoxide)
  • ethanol is derived from renewable natural resources such as corn
  • using ethanol helps decrease our country’s dependence on foreign oil

Some of the downsides of E85:

  • lower MPG (20-30% less)
  • availability of E85 stations in some areas
  • starting in cold weather can be difficult
  • unknown long term effects of running E85 on a system not designed for it

Everyone should do the research and make their own determination as to whether E85 is right for them. But for those who have chosen to run E85 I have a little help to address the cold start issue that I’ll share. Unfortunately the map values that come with the standard, off-the-shelf tunes provided by Vishnu Tuning are not optimized for the cold starting. Here are some cold start cranking map values that were developed by FT86club user Malt and further developed by one of our local friends mkivsoopra. If you are using RomRaider you can enter these values into your map.



Now admittedly it does not get that cold here in the SF Bay Area so I can’t say that these adjustments to the map will work for everyone in every climate. But Malt has said he tested the map in temps as cold as 21 degrees F and this map is further adjusted for even more effective starts, even on the very first crank. I’ve never had to crank my car more than once to start it while using these map values so I think it is a marked improvement over the other map values that I’ve seen posted elsewhere.

DISCLAIMER: This information is provided in good faith but I take no responsibility for problems or issues arising from the use of this information. I do not guarantee the accuracy of this information. Many on the FT86club forum have contributed to the information contained above it is not my work. For more information about tuning with OFT visit this link here and also this one. For more info on using E85 with Ecutek check out this link and this one for a Flex Fuel kit.

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