Hi, im going to change the engine oil and filters tomorrow morning on my 2002 wrx Impreza, what I want to know is........is it best to change it when the engine is completely cold and not been started so all the oil as settled OR is it best to run the engine for a while and let the oil settle and then change it while it is still warm,
Any advice appreciated.
Thanks in advance.

 

For all cars I've always let it run until it's up to temp, then let it sit somewhere level for 10 minutes so the oil returns back to the sump.
And I've only had two engine failures.

 

Get the oil up to temp by taking for a drive. Let the car sit for a while to allow oil to drain and it also cools a bit so you don't burn your hand. Drain the oil and remove the filter. Whilst the oil is draining pre-fill the oil filter this will take a few top ups to dispel all the air. Smear some clean engine oil on the seal and fit the filter, replace washer on sump plug and refit sump plug. Fill engine too top line on dipstick not the top indent. Now some say to disconnect the crankshaft or camshaft sensor and spin the engine over, I have had my bugeye for 14 years and have started the engine after filling and the car is on 114K miles producing over 400bhp and never been rebuilt. The choice is yours.