Doomsday probably had some superspeed himself, seeing as he was basically a mutated reanimated Zod. Plus in JL Superman had some real good speed feats. He also flies at way beyond supersonic. Somewhere around mach 3 id say. Which is much faster than what we've seen from Thor so far.
Thor has shown the ability to deflect bullets and laser blasts. I'd like to see a bit more though. I'd like to see some speed blitzing from him.
Superman was probably a bit off his game - having been exposed to kryptonite a couple of times.
He has some great speed feats in JL - best of all, the reveal moment where Flash realises Supes can see him, and then he actually knocks flash over, and effortlessly evading Steppenwolf's punch.
In terms of Superman's flight, he flies from Metropolis to the world engine (in the Indian Ocean) in a couple of minutes - ( a distance of around 7,000 miles, which means he was flying at nearly 140,000 mph, that's pretty fast).
Thor certainly deflected Surtur's flames, and The Destroyer's death rays (although Mjolnir should get most of the credit for that).
Kids let's be honest here. Thor does not have super-speed, he might have superhuman (asgardian level) reflexes, but he's not like Flash or Superman or even Wonder Woman (who could move fast enough to deflect a burst of gunfire aimed at civillians).
In comparison we very clearly see Thor run at a fairly normal pace in both TDW and Ragnarok. At the end of Ragnarok he propels himself forward in a spiral (kind of like M Bison in Street fighter). Mjolnir moves at incredible speeds, but Thor doesn't move a lot faster than an ordinary person. When he's flying, it's the hammer doing the work.
He does have some super-leaping ability, although it doesn't appear to be as great as that of the Hulk.
But does that matter ? Thor doesn't have telepathy, time travel, he can't phase through solid matter or turn invisible - but who cares ( Superman can't do any of that stuff either)?
Thor doesn't need super-speed, because he's a skillfull fighter, who uses his strength and weapons effectively (he owns Surtur and his army pretty easily). Also, his lightning bolts travel at about 220,000 miles per hour (in the comics, he's hit Quicksilver with lightning bolts ) so really, he doesn't need super-speed.