What are the most common fastener sizes on modern cars?
In all the Japanese makes it would be 8mm, 10mm, 12mm, 14mm, 16mm and so forth. American cars may have sizes in fractions of inches such as 3/8, 1/2, 5/8. However what you need is a full set because you never know what you will run into. I use a metric set for everything and found that the metric sizes interchange with the English sizes. For instance 3/8 is just about the same as 10mm. The only exception is 1/4 inch. That is 6.5mm and is right between 6mm and 7mm. So you need a 1/4 inch socket. The tool companies sell sockets in sets that are a lot cheaper that buying them separately.
