An average above 4.0 is not a better version of a 4.0; it is a different measurement. Either the transcript was weighted for course difficulty, which is a school district policy, or the institution prices a grade above four, as Arizona State does with an A+ at 4.33. A 4.1, a 4.8 and a 6.0 are all products of the first, and they say more about the weighting than about the student.
What produced the number
Weighted high-school scales add points to qualifying courses before averaging: commonly half a point for honours and a full point for Advanced Placement or International Baccalaureate. A 4.1 usually means a mostly unweighted transcript with a few weighted courses. A 4.8 means most of the transcript was weighted and most of the grades were A. A 6.0 means a scale that adds considerably more than a point, which some districts do.
Why the figures do not compare
Two schools weighting differently produce different numbers from identical work, and a school that weights nothing produces a maximum of 4.0 from the same transcript. That is why admissions offices frequently recalculate an unweighted average themselves rather than reading the weighted figure a school reports, and why a weighted number should always be quoted with the scale it was produced on.
Above four at university, which is a different thing again
Arizona State records an A+ at 4.33 on an otherwise 4.00 scale and caps the cumulative average at 4.00. So a college transcript can carry an individual grade above four while the reported average cannot exceed it. Comparing a weighted high-school 4.8 with a college cumulative average is comparing two measurements that share only a number line.
Questions people ask about is a 4.1 gpa good
Is a 4.1 GPA good?
It means a weighted transcript with some weighted courses in it. Whether it is good depends entirely on the school's weighting policy, which is why admissions offices often recalculate an unweighted figure instead.
How can a GPA be 4.8 or 6.0?
Through weighting for course difficulty. The size of the addition and the list of qualifying courses are set by the school or district, so the ceiling differs from school to school.
Does gpa 4.0 mean the same as a weighted 4.0?
No. An unweighted 4.0 is the top grade in every course. A weighted 4.0 can include lower grades in weighted courses, because the weighting lifted them.