Don't a lot of you get those numbers because of some of your modifications though? I mean with those additions and light driving thats why you mpg is as good as it is? Most people that I have seen post those kinda numbers have mods. Obviously your mpg is gonna be better than the gxp because of the size of the engines. Yes, No? what the heck do I know lol

My car is completely stock and I get over 30 on long trips. My 94 was completely stock and got 32. Yes, some mods will help with fuel efficiency, like an aftermarket CAI for example, assuming you're driving style merits good mileage.

I think I'd go with the SSEi myself.

I consistently get 30 mpg on the hwy in my 4.0, in fact, I've gotten 36.2 mpg briefly, well, Pete did, not me..heh.

Look, both the 3.8 and the 4.6 are gas pigs stoplight to stoplight, and on the hwy, the 3800 will get better mileage, probably based on the fact that you TWO less cylinders, and much lower gearing.

The DOHC engines found in the Northstar needs higher gearing, and the RPM'* at 70mph in a Northstar powered car will be higher then a 3800.

BUT, we don't drive Bonnevilles because its a gas miser, SO, give it a rest with the SSEi/Northstar nonsense and determine what you prefer

1. If you are a gear head and want to modify, get an SSEi
2. If you don't care about modification and just appreciate a capable and sophisticated drivetrain, get the GXP.

If looks is your game, you need to decide if you like the cladding and fascia of the SSEi or, the more reserved GXP.

17.4MPG here

Let'* not go down the MPG road. There are too many variables at play that can cause spurious correlations.

Drive both and decide for yourself.

I looked at an 03 SSEi and 04/05 GXP and decided on the GXP on looks, esp. the somewhat cleaner dash and lack of ribbing on the exterior molding. I also hate the way the fog lights seem to "hang" from the bumper. Looks great on the 96-99, awful on 00-03 IMHO. But you might like the low end power of an SSEi. I did like that, but I also love the sound of the N* as it is tuned in the GXP.

Both drive trains are fine, reliable and dependable. The fog lights in the GXP drive me crazy, but are easily fixed. I think (correct if wrong) they solved the Dex cool/ gasket disintegration problems that plagued my L36 and the L67.

You will not go wrong buying either one and I personally won't be offended if you don't choose a GXP.

just as an addition to the Dex issue, Dexcool doesnt affect all aluminum engines in the same manner it affects the cast iron/aluminum combo of materials found with the L67. In my years of hearing about Northstar issues, the coolant factor has never been a complaint.

Jim - yes. Dex cool is not an issue in the N* to my knowledge. But is it still an issue in 03 L67'*?

Charlotte got 22-23 average, but I only had mods for better airflow with the exception of the PCM. To a point, SSEis get better mileage as you modify them untill you get to serious mods, at least that was the case for me. Charlotte got 29-30 mpg doing 90 on the highway, bonnevilles, at least SSEis must be very aerodynamic cars since for how big they are because my Sonata with a 4-banger gets the same mileage at 90. So from what I know the SSEi is a good highway warrior and is decent in the city. I don't know why the Northstar is so much worse given it'* got a pretty small v8.