From the web I have gathered the following:
Buick GS 0-60 = 6.6, 1/4 mile = 15.1
Maxima GXE 0-60 = 6.5, 1/4 mile = 15.0 I assume that is the Maxima you had as the SE is dog slow.
These figures were taken from
http://car-stats.com/
I have raced a Buick GS at the track and it ran a very solid 15.1 so I think the numbers are right on.
The numbers for the Maxima were for a manual.
HTH