Why is there a difference in timing belt replacement intervals between two countries

Question

Specifically, the Subaru WRX sold in South Africa and Australia is 100% identical. And I mean that South Africa gets the Australian version of the WRX, there's no homologated version for SA.

Well, there is one difference: the service booklet of the South African WRX says the cambelt needs to be replaced every 100 000km (60k miles) whereas the ADM version says every 160 000km (100k miles). The weather and driving conditions between the two countries are virtually identical. The only difference between the two countries is that Australia has 98RON fuel where South Africa has only 95RON. But I can't see how fuel quality could impact timing belt service intervals.

So what gives? Are there good reasons why the same part on the same car, driven in the same conditions needs different service intervals?

Answer 1

I couldn't tell you why there is a difference, but both recommendations are wrong in my opinion. We always recommend changing a timing belt at 80,000 miles. No need to do it sooner and doing it later may cost you an engine overhaul from bending the valves when the belt breaks.

Answer 2

It's not only about the timing belt replacement. Subaru Sweden just changed the word miles to km. So, running the same distance, my 2005 Impreza needs two services in Canada and USA but three - in Sweden! Good för business. For them (105 miles = 168 km).

Answer 3

There are belts, and then there are belts. The dealer should have a list they can check and tell you what parts are on your vehicle and how long they last under normal use. Many dealers do not want to take the time to do this for you, so go by the owner's manual, or here on a forum. It is 100,000 km.

2 lane roads, 12 to 14% grades, heavy loads, stop & go traffic, all put a strain on belts. I have noticed motors and belts in the same vehicles in America last longer. When a motor is ran at max output, as any machine, they wear out faster. That includes belts. Manufactures cheat by listing how long they should last on the high end of use & load. So for flat ground driving good roads, you should be able to add 1/2 over that and be safe. Here you are at max life at the 100,000 km.

When you replace belts, you should have 3 to choose from non-dealer replacement: light, medium and heavy duty or industrial grade. Figure out then how long until you plan to rebuild the motor and buy that belt to save a little. Or rebuild and then upgrade belts to last until the next rebuild.