These don't trigger unless you change it to "kmph":
55 mph in kmh
https://duckduckgo.com/?q=55%20mph%20in%20kmh&kp=1&kad=wt_WT&kl=wt-wt
661 mph to km/h
https://duckduckgo.com/?q=661%20mph%20to%20km%2Fh&kp=1&kad=wt_WT&kl=wt-wt
IA Page: http://duck.co/ia/view/conversions
Maintainer: @mintsoft
I'll sort out km/h; but kmh isn't the same thing, that'd be Kilometer-Hours.
Actually km/h already works?
Nice, km/h does seem to work now, strange.
Do you think it's fair to say that most people mean kmph though? Or could we use the presence of mph as a hint?
Given that kph works I'm inclined to say no. I've never seen anyone use "kmh" to mean km/h or kph and both km/h and kph work.
I could not find any reference to "kmh" as a unit of speed. Not on wikipedia nor anywhere else listing SI units of speed.
It's not a matter of whether it is an "official" measure of speed, people are typing it into a search engine and expecting an answer. Google gives them the answer, we don't. The example above is from a real user.
Google gives them the answer, we don't. The example above is from a real user.
Hmm, personally I'd say that Google is wrong here. Google tends to substitute its own judgement in place of the users; possibly the biggest reason I switched to DDG is that it didn't. That is, however, a matter of opinion.
It is probably worth noting that google has actually autocorrected "kmh" to "kph", it doesn't 'think' that kmh is a unit of velocity. We don't currently have a way of applying query autocorrection into an IA; I think that would be a better way to implement it in general, rather than cluttering up IA's with incorrect/misleading information.

@mintsoft I support your point. This IA do what it is made for and since I am from Asia generally people here use kmph or km/h instead of _mph_ to refer speed, they don't use kph or kmh at all. Infact this is the first time I had heard someone saying kmh to mean kmph
Looks like this problem has been solved.
Feel free to introduce some additional aliases or add them to the edge cases issue.
Most helpful comment
Hmm, personally I'd say that Google is wrong here. Google tends to substitute its own judgement in place of the users; possibly the biggest reason I switched to DDG is that it didn't. That is, however, a matter of opinion.
It is probably worth noting that google has actually autocorrected "kmh" to "kph", it doesn't 'think' that kmh is a unit of velocity. We don't currently have a way of applying query autocorrection into an IA; I think that would be a better way to implement it in general, rather than cluttering up IA's with incorrect/misleading information.