Hastd2:
Those space-saver spares aren't meant to be run for long, or fast. Most have a 70-120 mile lifespan and can't be used at over 55mph. Those aren't ultra cautious guidelines either. My boss put his on and drove 150 miles from Sheffield back up to Newcastle on his Astra SRi, doing 65mph. Trouble was, at about 120 miles in, towards Scotch corner (Darlington outskirts), the tyre stripped and burst. Be careful!