T4xx Trans Family dark side.

[2003 SSEi]

there is more room in the back of a GP than a Bonneville. I have both cars sitting in the garage. It'd be a toss up (if the Bonneville Was stock) what car I would like driving more

[viper79]

there is more room in the back of a GP than a Bonneville. I have both cars sitting in the garage. It'd be a toss up (if the Bonneville Was stock) what car I would like driving more

Thanks for the reply. I did know that the GP has more room. I think I'm leaning towards the Bonnie. I like the fact that not everyone has one, Bonnie in general, around here. GXP will turn heads. "What the.."

[donky4444]

I've had both cars for 3 years each. I was very very lucky and had no big problems with either car. I sold the Bonne with 90k and the GP with 75k. Knowing the trans issues the GP IPAs I was a maint freak. I did full trans flush and filter every 20k miles. I also went with an Overkill Motorsports tune. It wasn't the most powerful tune out there but it did a lot with the trans and the drivability. I also had an Intense FWI and Magnaflow cat back on it. The Boone has more comfort and options but the GP had more go and better braking. As far as the dod oil consumption I found that it was really bad with Mobil 1 but once I switched to Valvoline it wasn't bad. For the forst 2 years I hardly had to add any oil over a 7,500 span and the last year it was closer to a qt between oil changes. Guys using mobile 1 usually had to had up to a qt every thousand miles. I sold both cars due to the mileage getting higher and the known issues they each had. I figured 3 trouble free years was lucky and sold them before either started having issues. The Gp held its value way better than I thought it would.

[2003 SSEi]

there is more room in the back of a GP than a Bonneville. I have both cars sitting in the garage. It'd be a toss up (if the Bonneville Was stock) what car I would like driving more

Thanks for the reply. I did know that the GP has more room. I think I'm leaning towards the Bonnie. I like the fact that not everyone has one, Bonnie in general, around here. GXP will turn heads. "What the.."

agreed, the Bonne GXP was a lower production than the GP, I also think the Bonneville GXP "looks" better than the GP GXP

[viper79]

Thanks for the insight. Having that said. What is the main issue(s) with Northstar?

[94SilverSSEi]

Thanks for the insight. Having that said. What is the main issue(s) with Northstar?

Everything!


Seriously though, it is a huge DOHC V8 in a FWD car (same issue with the LS4, but the LS4 doesn't have as big of heads).
Some say the headgasket issues that they were plagued with were solved by '04 but I had a Bonnie GXP and it suffered a headgasket failure. Although this may have been an oddity but still it happened.


That being said and as much of a pain it is to work on. I would still take the Bonneville GXP over the Grand Prix any day. IMO it wins on looks alone, hands down and has the better transmission. And it has wheels that can actually be rotated

[GotBonneBWitMe]

I have always been a fan of the Grand Prix. In fact, that car is what initially drew me to Pontiac. Ive never personally had one, but I have always heard that in some aspect they can be more troublesome than a Bonneville. And while the Bonneville GXP is more rare than the GP GXP, I think I would have to go with the Grand Prix. I honestly like how they look better. BUT then comes the fact that a Grand Prix is more common than a Bonneville. Which is what has kept me with my Bonneville (Even though I do not have a GXP). I always consider and wonder if I would take on a GTP trade for my SSEI.

But it is up to you at the end of the day. Both can be/probably will be fairly costly with the maintenance. So it's just a question of which one would you rather deal with. And like the best.

[94SilverSSEi]

Plus Grand Prixs get a bad rap for getting beat on. They targeted a younger crowd with the grand prix, so they tend to be more beat and less cared for. Not all of them, but it's easier to find a Bonneville in good shape. At least around here.

[bobgto65]

I have an '02 SSEi with 200K and instead of fixing it up to keep driving it, I bought my '04 Bonneville GXP 9 months ago with 32,600 miles on it. There is a big difference in the feel of the car and engine and ride. When you kicked in the supercharger on the SSEi, you could feel it, but the Northstar seems more refined, and makes its torgue and horsepower at higher RPM. I think it has 3.31 final gear ratio compared to 2.93 on the SSEi to compensate for that. The engine likes to be treated to WOT runs and runs at high RPM, otherwise you get carbon build-up. You can feel the extra 35hp in the LD8. And the transmission shifts are firm. The suede seat inserts keep you from slipping like the leather around turns. You can find '04-05 Bonnevilles with low miles, under 45,000 on AutoTrader or Cars.com, although you may have to travel to get one. These cars handle well in the snow with All Season tires so the lack of 4WD does not bother me. You can't do much to mod the drivetrain for more horsepower. And you have to keep up with the maintenance, like changing the dexcool every 5 years or less to prevent gasket damage from acid build-up.

[viper79]

I'm still torn on bonnie gxp or torrent gxp. It might have to wait till next year, but life is a journey. You never know what exactly waits on the other side of the door.

[2000Silverbullet]

Be forewarned. The 6 speed tranny on my Torrent GXP blew at 78,000 kms. Glad I had the extended warranty. $3500 repair was covered with only $100 deductable including the one week rental of a replacement vehicle.
Buy used from a dealer and get the warranty option.