Afaik 182 and ph2 172's have the same ratios. Ph1 have different ratio's, as they aren't lardy pieces of s**t .Shadowness said:Slightly different ratios too
Seems to be some confusion here.
Ph1 172 and 172 CUP's have a speedo sensor in the gearbox itself, the 2 boxes are different ratios but can be used on either car.
Ph2 172 and 182 use the ABS sensor for the speedo, and don't have a sensor in the box.
So going by the OP's (Car: clio 172 cup (S7U OE)), he'll need either a Ph1 or a Cup box.
If he has a normal Ph2, then yes he can use either 172 or 182. 182 benefits from bolt in diff, rather than older (SH*T!!) circlip.