I think I can help out on this one.
And lookup the specs on the Tiburon. And then goto:
And look up the Specs on the Accent GSi.
I believe that since the power output of the Base Tiburon 1.6 in UK is very close to that of the GSi, that they are the same engines. Basically the GSi in Canada has the base motor for the Tiburon in UK. And in UK for the Accent you can only get the 1.5DOHC as the top engine, the same as the 96-97 Accent GT sold here.
So the engines are not related as the 1.6 used in the Early Elantras sold here was a Mitsu motor and the 1.6 in the Accent GSi and GL (2001 + models) is a Hyundai engine.
And besides, if you look at the torque ratings, the torque is produced MUCH lower on the scale (3000 vs. 4500) which means better off the line acceleration even if the overall Horsepower rating goes down a bit.