About 6 months ago I purchased a 2003 MITSUBISHI Magna executive series 2, 3.5ltr. It has just done 20k and I would like to do an oil filter change.
2 Questions my car with this many klms: and I live in brisbane.

1. How often should I do an oil and oil filter change. every 5 or 10k.
2. What grade oil should i use 20-40, 20-50? and does it matter what brand?

Older car id like to say every 5000, I have just fitted a brand new motor in mine and so ive been doing 7500, but will drop that back down to 5000 as the motor gets older.

Honestly bud a search would've given you the answers because questions regarding oil changes and what type of oil to use have been covered many many times.

However with that said, most people on these forums will use Penrite HPR10 in their car and im among one of them as well. I used to hate Penrite oils by a horror story I saw on the net but when I started using them again I have nothing bad to say about them. Thats a 10-50 oil so covers a nice large range of viscosity, as for the filter I always use Ryco but if you can get a genuine filter at your local dealer in the same price range Id snap one of those up. I never use the cheaper Coopers filters.

oil change usually every 7,500 to 10,000kms is in the right field. if the engine has seen a lot of wear, changing oil around the 5,000km mark is good practice. as p&h said, penrite HPR10 is more or less the go-to oil.

It all depends on how hard you drive the car too, the harder you drive it the more frequently you do oil changes

If you're driving it like a grandmother, 7500 -10000 with good oil is fine, if your a leadfoot then 5000 is better for the engine

Edit: phone did the double post thing again

Sorry have to totally disagree with the above all together.

What quality of oil, how often the car is driven, how far the car is driven on each trip makes a huge difference

My recommendation would be 7500km or 12 months at most, IF the car is a short trip car ie kids to school and corner shop car move that back to 6 months

Here in the shop we us the 10k or 12 month rule on most cars for changes (given we use full synth oils) but we also speak to our customers to get an idea of how the cars are driven thus if we know the customer does a lot of short trip we will move the interval back to 6 months and 7500km

so, OP has a 10+ year old car, with just 20k on the clock, and going by all these statements, its theoretically had 2 oil changes? i would be more concerned about how much, if any sludge is in the engine before anything else. i could be wrong however and just blowing wind up your skirt, im not sure how this would effect a magna engine?

That is the issue with super low mileage cars, often they are serviced when the odo comes to a particular mileage Recently had a TJ in here with 100k on the clock, motor internally has so much crap in it from lack of changes and the smoke it blows is outstanding for a motor of such low mileage

I suspect where the OP says 20k he means 200,000k.

Thanks for all your help guys

An yes, sorry, I did mean 200.000k