DUI is only a misdemeanor in most situations. Speeding is usually just a traffic infraction, even at 20 over, unless they can also prove reckless driving (which is criminal, but also generally only misdemeanor criminal).

In CA, the fines double at 15mph. Anecdotes suggest they rarely even bother people going less than 15 over and often write tickets for more than 15 at the lower level anyways. They actually have a law that makes exceeding 100mph considered reckless driving.

Then we get further away into NV, UT, ID, MT, they have higher speed limits (75 and 80) to begin with. NV, speeding is a misdemeanor (fine no more than $20 per mph over the limit capped at $1000 which implies misdemeanor charges for going 50 over!). UT's reckless driving law kicks in at 105mph. ID doesn't have anything super clear on the subject, but there doesn't appear to be any explicit excessive speeding statute. Similar in MT, though school and work zones can upgrade the infraction to a misdemeanor. No mention of felonies in any of those states...

I think you have some incorrect perceptions on how things work in other states.