[OldNuc]

All of the actual wire core is usually the same size in all the different sizes. All you are buying is thicker insulation and usually a pretty color. The DIS system does not generate voltages high enough to warrant a thicker insulation. The reason for staying with 7mm is all you get with the larger diameter is a thinner wallet. You can use 8mm and it still fits in the stock clips but its a bit pinched which is not good either.

You will find some that have a larger diameter wire core and this will function better with the high voltage systems. You will know if you need it though. You don't with a stock Saturn ignition.