You need to give people info on the motor, rebuilt or standard, if its rebuilt do you know if its a loose or tight rebuild? Is it street driven or raced?
Between a 10W 40 and a 20W50 depending on how tired the motor is and how hot it is where you live for a street motor. And id prefer to buy a semi syntheic oil and be able of change it twice as often than a $90 bottle of full synthetic.
i been using castrol magnatec, and shell hx7 both 10w40 in my vr4 motor. This is as light as you would want to go, unless in winter it snows where you are.
Im starting to like the idea of Penrite HPR10, 10W50. Especially in summer. And also they advertise it has a high ammount of zinc, Forced Performance in the States put out an info sheet on oil needing a high zinc and phosphous content when pushing turbos hard. So im gonna switch to that. Zinc is a great mollecular level lubricant in oil but is removed from a lot of American oils for emissions reasons, if Penrite still advertise it we must not have the same standards on zinc content in Australia.
15W40 or 10W40 in winter and 10W50 or 15W50 in summer would be good if its hot where you are.
A decent semi synthetic oil is plenty and change it often i do every 3000 kms or less if im working on the car anyway. For example my car (a few years older than your evo 3) calls for an SAE grade SG-SJ oil, an SJ mineral oil costs $13, and just about everything else on the shelf will exceed this standard anyway so that's the type of oil around when my motor (and a few years later your motor) was built, semi synthetic SM on SN oil thats say $40+ will well exceed what the car was made to run on.
If its being raced then full synthetics and heaver oils (--W60) are worth looking at if your oil temps climb.
Have a google search on oil classification and what each aprt of the oil weight means and make you own mind up to some degree. I find oil very interestng and always trying to learn more about it.
