motor oil

I used to work in an oil testing lab and would liek to clear up some misconceptions. These recommendations are for street driving of cars that do not have extreme modifications. If you are racing or have extreme lift cams or other very high performance parts this info does not really apply because your drving conditions are different.

for multi weight oil like 10w 30 or 20w 50 the oil has viscocity modifiers added so it is more pourable at a lower temperature. what this means is at low temperature a 10w 30 pours like an oil with a viscocity of 10 so it will flow more easily in a cold engine. This is important even if you live in the south because your oil will begin lubricating your engine more quickly when you first start it when the majority of wear occurs.

In normal street driving I don't reccomend additives. The additives in the oil are balanced for specific purposes and adding other additives will throw off this balance and create unintended consequnces. I am not a complete expert but I do know if you add excessive anti wear additives you will decrease the oils ability to deal with oxidation. This causes the oil to get gummy and create that nasty oil varnish you see in engines.

A lower viscocity oil will slightly increase performance and mileage but it may not be noticable.

My personal reccomendation is a 5w 30 or 10w 30 for any and all vehicles and if you want you can use a synthetic but it is not necessary. If you live in extreme cold (Northern MN or AK) I do reccomend a synthetic 0w 30