I doubt the NISMO is faster than an LE or SE, but I do believe they are geared lower, at least the ones with the auto transmission are. I have read that the 6 speed SE and 6 speed NISMO have the same rear gear ratio. I also believe the NISMO is heavier than the others due to the extra hardware that is part of the off-road package. So, the combination of the lower rear gear and extra weight probably have a significant impact on mileage. I know for a fact that the LE Auto has the tallest rear gear, and they tend to get the best gas mileage!