2004 Bonneville GXP 4.6 Northstar thoughts? (Page 1/1) 86soon3.4 MAR 26, 08:01 PM What do you guys think of the Bonneville GXP with the 4.6 Northstar V-8 in it? Fuel mileage? Engine or tranny problems? Looking at one for my wife. Steve fastblack APR 17, 10:57 PM I actually just got an 05 GXP a couple weeks ago. Now, I've only owned this thing for a couple weeks but so far I love it. I'm getting low 20's for MPG but that's because I can't keep my foot out of it. The car isn't overly fast but definitely enough power to make things interesting. The exhaust note is something you will fall in love with. Inside is GM as usual with a touch of class, seats are very comfy and look nice with suede inserts. I obviously cannot comment on reliability just because I've only had it a short time but so far so good. As far as the Northstar, I've heard stories of oil and coolant leaks but with regular/proper maintenance you can stay on top of this. Mine has about 100k on it and so far no sign of this. I know it wasn't much but maybe I helped.