my buddy and I were on our way to college, he has an 89 305 tpi a4, at about 30-50 range, we kept pulling even (we could only get up to 50 due to traffic, once we hit open road, he floored it (it blows a little smoke upon flooring it) and I walked him easy, started at about 50 mph and by 80 I had 2 cars on him

 

hmmmmm. his tpi must not have been running well because he should have walked you. or perhaps yours is in excellent running condition. either way, nice kill...

 

If you think you can run a 15.5, then I'd say you two should be pretty much even.