People have all levels of experience on this forum, from a teenager who got his first car to people who have been in the business for 40 years. And some retired from the business or the petroleum business. There are also levels of education on the forum also. Some check the forum once or twice a day and some just come to ask a question.
Some like to give opinions and other will only accept a scientific test. Most are somewhat in between. People provide opinions on things they have tried, but readers should know many things are subjective. If you say you just changed your diff. gear oil to synthetic and tell us you picked up an additional 10 MPG, then I might think you just wanted the mileage to be better.
In addition there are people who have little time and those who can spend all day on the car. Same with respect to money.
If someone asks for decent brake pads for his daily beater and only wants to spend $25, people can probably suggest some. And they will be better than whats on the vehicle. One the opposite end, someone wants new brake pads for his 1100 HP Shelby Mustang (that would be me in my dreams) and people will probably suggest Hawk pads.
So the forum welcomes all.