How often do you change your timing belt?

[124spiderman]

With regards to changing timing belts these days, the old 124 coupe manual recommended 40,000km (25,000 miles) or 4 years whichever came first.
BUT.....since our cars don't do the daily driver mileage that they used to (my car driven around 7000 miles in 6 years) AND that the material used for timing belts these days is far more superior of what Fiat used back in 1967-70's I'm wondering if how many of DOHC & SOHCams get changed with the original Fiat recommendation of 4 year/25,000 mile interval? Mine is on its 6th year with a belt and tension bearing change coming up very soon.

[AriK]

I'm at 5 years and 14,600 km. (+/-8700 mi). I have a leaky water pump (maybe gasket) and i was do i/dont i to do the whole kit. I've finally decided that i'm changing the pump, TB, tensioner and rad hoses. This time around i'm also changing stuff i that didnt do last time such as seals and thermostat. Buys me another 5-7 years of not thinking of that area of the motor. Hopefully.

[KidDingo]

Brooklands manual says to change the timing belt:

1971 - 1978: every 25,000 miles (~40,000 km)
1979 - on: every 30,000 miles (~45,000 km)

Wheel bearings and lambda sensor (if present) should be done at the same time, according to the manual.

Given the rate of deterioration of rubber, might be good to do it every 5 or 6 years, despite the mileage done?

[paintdudeluke]

New cars with timing belts use the same quality belts, what do they recommend? I can't see a fiat engine being any harder on a belt than any other engine.

[azruss]

I'm sure the durability of a modern belt is twice that of the old belts. I have run an old belt to 60k. I would guess the condition of the cam wheels and tensioner as well as driving habits would have a lot to do with the durability.