Dnt risk it belt manufactures usually say to change every 5 years and you do the pulleys while you in there as well. I have noticed cars with belly pans tend to have the belt last longer up to about 7 years, that's the longest I have seen a belt on a car, unfortunately chains are unreliable and its down to a throw of the dice if you get over 100kmiles or it stretches before your reach 100k miles.
I've seen it in writing, more than once, that the wee FIRE engines should get a belt every 5 years or 75,000 miles - whichever is the sooner. If you are doing a lot of local stop/start city type running I'd be changing it even sooner. On ours I aim for 5 years/50,000 miles and as none of the Fiats do high mileages this means I'm looking for a nice sunny weekend as the 5 years gets near. The belts on ours don't really ever show much signs of wear or cracking and would probably go on for some time yet. Water Pumps often show early signs of trouble looming with small signs of coolant stains and "loose" slightly rough bearings when spun up by hand after removal. The tensioner idlers seem to fare well.
Yup, VVT=Pain in the bum. Not that long ago the Astra started going clack clack clack on start up. One timing belt kit, two new VVT pulleys, a couple of VVT oil control solenoids and other wee bits later it was running lovely again but left my pocket book weeping - despite the very considerable saving made on parts buying from Autovaux - Genuine Vauhall parts too!
