oh and before you dump the existing oil, put an engine flush through it in case you have a blockage, sometimes this can help remove sludged up motors, failing that, you can do 1/2 a litre or so of dextron into your oil run it till warm leave it stand, warm it up again then dump it. dextron contains heaps of detergents and what not. bit of a bush mechanics that one. but use engine flush before you attempt the dextron. its a last resort. but do it before dropping the motor. you may well be surprised

My last service was about 5200ks ago oil was shell helix hx7 15w40