Hi everybody. This topic may have already been started somewhere but I wouldn't know where to look. I'm a Grade 5 adult (very much so ... ) student (piano) and am taking my exam in June.
I keep feeling sort of insecure with the contrary motion but I do them quite well. My parallel motion scales are already pretty fast and fluent (I play them for 4 octaves at semiminim = 88, which is very fast by Grade 5-6 standards) but my teacher says it'd be good to speed them up a little (I've been taking piano lessons for 2 and a half years only so y progress seems to have been fast, I think9.
Now, I wonder where one can go from here and especially what could be done to speed them up a little bit. Any ideas?

If you're very secure at 88 you can probably go up to say 92 per 4 notes without the need for much adjustment, then make sure you can play them at the new speed with the same evenness of rhythm and touch before going up another notch. If you speed it up gradually, it won't feel much of a change. Also, I found it helps keep the rhythm if you do it in bits - e.g. if you play a scale an octave at a go at the new speed, pause a beat, and then the next octave making sure that everything works before the pause, you can then increase the playing at speed bit to two octaves before going all the way up and down. I'm not sure it makes any sense when I write it down!

Good question.

Firstly make sure that your scales are absolutely even, both in terms of rhythm and touch/tone. It is well worth playing them very slowly too, to make sure they are totally controlled (i.e. even) even at a slower tempo (discrepancy in evenness can be highlighted by reducing the speed).

Then try different rhythms, such as dotted quaver - semiquaver and vice versa. This will reduce the distance between every other note, a sort of halfway house. Also experiment with different dynamics and a range of articulation (staccato, slurs, etc.).

Sorry, I have to ask... What is a semiminim? Or do you mean a crotchet?

It has

No magic bullet. Frequent repetition (precise and accurate), and patience.

Just a small tip, which may be helpful for you, I used to sit an inch or so further away from the piano when playing scales. This might help you play them faster as long as you are not overstretching. (Hm he's not playing scales !! Maybe Bartok !)

Nice to hear from an expert like MadTom that my progress has been fast ... but then, why worry about how fast/slowly one does things when all that matters is the result, I wonder ...
However, I suppose the relief I get to hear somebody say I've been fast is most probably connected with a hidden feeling of inadequacy at 52 ...

I usually, when playing them faster, start an octave lower, ie, two octaves below middle C, I dont know why it helps really, I guess it stops having to turn half way through the scales, slightly.

Unless you're sitting too near the keyboard you shouldn't have to turn - sit further back and lean.