I am on some car forums where people get used oil analyses in order to maximize their oil change intervals based on the type of oil and driving conditions their car experiences. It sounds like just about any conventional oil will work fine for most vehicles with the 3000 mile change interval and any oil filter while people have gotten much farther with more costly synthetic oils.
Has anyone here really found a standout oil based on these scientific tests? Some of the car forums I am on really suggest any European rated oil of the proper viscosity or slightly thicker. I understand the specs for oil are a lot more stringent in Europe than the USA so they typically have better oils.
It also seems that people like running a slightly thicker oil than specified in the manual, especially in hard use situations like racing. For example, I see references to people using a Rotella T6 5W40 in engines that call for 5W30 or 10W30 without any issues. The wear metals in the analyzed oil are much lower although there is about a 5% penalty in mileage due to the thicker oil. It sounds like the drive for increased mileage by the EPA has led automakers to suggest a thinner oil than might be ideal for engine wear. Now, that being said, if you can get 200,000 miles or more out of an engine using a thinner oil, that 5% fuel economy savings will more than likely more than pay for a new engine or rebuild.
I am currently running synthetic in everything I own. This includes mowers, etc. as well as even my two cycle mix oils. Some of this is the store brand synthetic when it is on sale with whatever brand filter they have bundled with it for my older trucks. My lowly Geo Metro gets the Mobil 1 European spec 0W40 as this is an oil that has been highly recommended by enthusiasts of these tiny little cars and their engines. Although any 5W30 meets the manufacturer requirements, these tiny little engines are hard working and hard on oil. They are not forgiving to having dirt/sludge in their oil pressure regulators, hydraulic lifters and such. A common problem is something causing the hydraulic lifters to overpump and then the valves burn. For the money, you cannot beat the price of this European spec Mobil 1 as it goes on sale for the same price as all the other Mobil 1 products. I understand some of the other Euro spec oils are actually better, but this one doesn’t cost me much more than conventional oil in most cases.
Anyone here big into oil analysis? I have never done it but have always been curious. If so, has anyone found a favorite oil or at least a favorite oil for the car it is being run in?