Paul
If it is an older used model, you coudn't have picked a worse version of the Galaxy. A bit of research would have told you that the 2.0 petrol version is very poor , thats why they are so cheap. Everyone in the know wants the diesel so prices are higher. But as in everything in this world ,you get what you pay for.
Slow and thirsty sum it up.
However the new Galaxy has a much more powerful 2.0 engine.
If you want some real advice, sell it and buy the diesel model.