OK, enough of the not realistic comparisons for so many reasons that I won't even go into. Here is some reported data. I'd call them facts, but there appears to be some slight discrepancies.
From Edmunds and comparing 1999 GTP to GS. I just chose 99 because it's the year my car is.
GTP - curb weight - 3414
GS - curb weight - 3543 GS is heavier by $130 lbs
Not sure if I totally buy that because Edmunds lists both the GT and the GTP the same weight at 3414, but has the Regal GS at 3543, and the LS at 3439
Motor Trend lists the curb weight of a GTP sedan at 3500 lbs. So IMO the data is probably not totally accurate and the GTP probably weighs about 100 more than the GT just like the GS supposedly weighs more than the LS by 104 lbs.
Motor Trend street times. This is a little harder because you can't find every exact year tested.
1997 Buick Regal 0-60 6.6, 1/4 15.0@92.3 Buick Regal GS - Motor Trend Magazine
1997 GP GTP 0-60 6.6 1/4 15.0@92.3 '97 Ford Taurus Sho VS. '97 Pontiac Grand Prix GTP - Road Test- American Car - Motor Trend Magazine
Basically what I'm saying is that you guys with your GTPs that think GM made them faster or lighter, are just wrong. Supposedly the GTP has a little firmer bushings and so forth and according to edmunds has a slightly shorter turning radius. If you want to go ahead and say the GTP is a little "sportier" than the GS, then OK. Not sure I would dispute that, but highly doubt that the difference is really significant and although you may swear by it, the butt dyno might be a little biased. Now a 300k car with an 80k swapped motor and a different driver, I could totally buy that one car is slightly faster than the other. I raced a couple GTPs stock for stock before I had done anything and I'm telling you there was no difference.
I mean, I get it. The reason us GS drivers bought and love are Regals is because of the sleeper look and that the lines are not quite as aggressive and that it's sort of a surprise. GP drivers like that little sportier look and more aggressive look more of a "look at me". Something about the aggressiveness makes it "feel" faster, but it's not reality. I had a college roommate that was exactly the same height as me, but he was reeeeeaaaaaaallly skinny(like 135 lbs skinny). I was pretty athletic and the time and weighed about 180lbs. Everyone thought I was taller than my roommate even though in reality we were the exact same height. This comparison between cars is a similar comparison, but it's just exactly the same phenomenon.
