I'm sorry, I just did the Vtech tune, before the Vtech tune, my Spark would only top out at 42 mph, after the Vtech tune I only saw 52 on my screen, but my gps said different, however, I only ran it like 3 minutes.. So maybe another run this weekend? I'll be at lake Mohave/Mead + Colorado River this weekend and do a 10 minute run and check it out.
I think my gps was wrong, top speed recorded on a spark without turbo is 54.5 per other forums.