1.5 golf help!!!!!!!!!

Would a 1.8gti engine fit straight into my mk1 1.5? I have been having trouble and terrible mpg from my 1.5 for months now and would be greatlfull of any help from this thread. I know the mpg would be probably just the same but at least me car would have some balls then!!!  

Many thanks, Ben

The engine would fit, but you'd need to do some fiddling with wiring (and fuelling I think) to make it work - worth doing if you're confident with your DIY skills and have the room.

HTH

Rich