I've been looking at a lot of info about the Malibu lately in view of my the folks just ordering one and I see a few things here that seem wrong.
1. The 2008 LTZ is only offered with the 3.6L with 6 speed automatic. Our local Chev dealer seems to believe the 2.4L will continue in the LS and LT models with the 6 speed when they start shipping them with the 6 speed, not be a new option in the LTZ.
2. Even the 3.6L achieves 36MPG highway according to Natural Resources Canada. the present 2.4L 4 speed combo achieves 43mpg highway per NRC, and the Hybrid is rated at 46 MPG highway. All considerably better then the numbers you've posted.
3. Why don't you give a source for these claims. Is this from Manufacturers data, A press release, a magazine review, or a coded radio message that you used your little Orphan Annie secret decoder ring to decipher?
When GM Canada officially announces the LTZ will have the 2.4l, 6 spd combo I will believe it. Certainly nothing on their website would indicate that at this time. If the US arm offers the LTZ with a 2.4l that doesn't necessarily mean that the same car will be offered here. (assuming that this is US data, based on the mileage numbers. certainly nothing you've left me sure of)
If these are not American Mileage numbers then I foresee General Motors not being able to move these things when the older combination got 43 MPG Highway as noted above
Frankly I believe the new Malibu is so well designed compared both to its predecessor and the competition that it will be a success regardless of the rabid "GM is great" comments and the "GM will screw it up" replies that always follow, so perhaps we could skip that part this time.