18's on my G8 Would a 20 be bad?

[Lloyd]

PS,
I like LS2 better than any G8 forum.........

My G8 is currently running the stock 18 inch rims. I was just about to purchase a set of 20 inchs from a new camaro I found on ebay. BTW, they look incredible on the G8's. A buddy of mine said I will lose almost .4-.6 off my quarter mile time if I do this. He spends a lot of time on the local quarter mile track, but I am just about to start. He suggested I keep my 18's and buy better tires for them.
What are your thoughts?

[Sandman]

If you only care about 1/4 mile times he is right - larger rims will increase unsprung weight and drag your times down, though he might be exaggerating some.

[dingle]

Are you not going to keep your stock rims too? Best of both worlds? Then you can put some drag radials on your stock rims and see what you can break.