Wrapping a 'MAX' Function around an IF Statement?

Hi,

I am trying to wrap a MAX function of some sort around some sort of IF statement. The same sort of thing as a SUMIF, but a MAXIF, if that makes sense?

So i have for instance one sheet with many different registrations on some registrations appear more than once. Another colounm on that sheet has a max speed. What i want to do is, a formula to look for a certain registration (going off another sheet), and then get the MAX speed, from the set of MAX speeds for that registration.

So if i had 5 lines for registration DV51 AZZ, it would have 5 max speeds. On the next sheet i want it to look up DV51 AZZ, and bring back the MAX number (speed) from the 5 max speeds.

I hope this makes sense! And i hope its possible??

Thanks for any help
i love this forum.
Jez