What are your recommended belt change intervals?

The belts are lighter so they reduce the rotating mass and allow the motor to be speed up and slow down with less energy. Lots of valve trains especially 4 cam V6's and 8's have valve train dynamics that cause a lot of vibration and shock loads to the drive system. Belts tend to absorb and dampen that. The more aggresive the cam design and stronger the springs are the worse it is. Dino's suffer from it to some degree but the Maserati V6'S really had problems.

Belt drive motors also are lighter, simpler and less costly to build all other factors being equal. Chains wear and require replacement too, in many cases at similar mileage. When they do it can be very costly. The real savings is the fact that a chain drive motor sitting in your garage is not wearing out, a belt drive motor is.

 

What Brian said! Careful what you wish for.
IE. F50 with the Morse type chain cutting through the case hardening of the cam gears in 10K miles. Bringing back the roller chains would be a positive move in my book. Currently have (2) 330 engines apart with 65K++ on each and the chains are getting replaced only because it is proper to do at a rebuild. Also have a C4 with the early tensioner apart getting new chain and tensioner bits well before it should need them due to a failed tensioner.

Dave

 

Every time I read one of these threads I have a "Scared Straight" moment.

 

No need to feel that way. Folks simply do not realize how good they have it with the 12 cylinder cars and T. belts. Simple to replace, reliable........ Just pointing out problem areas when I find them, not pointing out a design flaw.
With belts this easy to replace there should be no arguement over doing regular maintaince.
Brian stated it well, chains do have problem areas as well. Belts are a known thing and serve their purpose well.

Dave

 

Dave As to your C4 tensioner, be sure you have the updated version, (there have been several I am told) its actually cheep and easily installed.

 

If you take all of the replies for the Maranello belt change interval and average them out, it seems to be around 3.5-4 years per change.

 

Thanks for the great answer.