Ask an expert

I read an earlier 'Ask Jack' that "if the vehicle is more than four years old and is petrol, then a regular service every 6 months or 10,000kms whichever comes first would be my recommendation".

I use my 7-year-old car 4 times a week, total of 8 trips, each of about 15 minutes, on a cold engine. Can I extend my service intervals to longer than every 6 months?

Also, must I change the crush washer every oil change? I haven't for 3 years, and it seems OK (no leaks).

A brand of synthetic oil advertises that a one-year oil change interval is fine. Should I use such an oil to save myself time and effort on oil changes?

Leonard

From the "Ask Jack" archives - 23 April 2010

It would depend on the make and model of vehicle to be honest.

I would be reluctant to go over the 10,000km distance but you could stretch the time to 12 months.

That means an oil change every 10,000km's or twelve months whichever comes first.

You would definitely need to be using a good quality engine oil also such as a 10-30 viscosity.

Re the crush washer; my recommendation is change it every time. I have seen too many occurrences where the washer has not been changed and leaks have developed.

The problem is removing the drain plug to fit a new washer, it's like carrying out the oil change all over again. The washers are normally very soft and only designed to be used once.

I suggest you have been very lucky in the past. If you do the oil changes yourself it's a risk you can take I guess, but in a retail workshop environment I totally support the change of the washer every time.