Don't forget that the Elio engine is actually detuned. Paul Elio himself has told us that they are planning to sell us software which would allow us to program a more powerful tune.
my experience with aftermarket engine programmers has been for use with both the GM 5.3 gas and Duramax diesel motors .... both made a difference in performance, the biggest gain coming with the Duramax .... use of those programmers could have caused problems with warranty coverage for repairs but we had no mechanical issues so it didn't become an issue .... if Elio Motors provides the programming software, there shouldn't be any warranty implications .... even though I may never use it, such software would be an option I'd be interested in
Jim