Without popping the hood, you'd be hard-pressed to find the visual differences between the new... 
While the new engine's 110-horsepower deficit might raise eyebrows at first, the 218-hp unit can move the G25 plenty fast—and it's smoother than the larger engine, according to initial drive reports. Unlike the G37, you can't get the G25 with a manual gearbox; it comes only with the seven-speed automatic, which we've noted is an excellent companion with the larger engine in enthusiastic driving but a little lumpy and indecisive around town.
Even feature-wise, it's much of the same for the G25, and that's mostly good with respect to features, too. Infiniti has dropped the Base G37 model, and the G25 now comes in Base and Journey trims, with the G37 offered in Journey and Sport models. Both the G25 and G37 can be had with all-wheel drive—and as such they're called the G25x and G37x.
Getting down to numbers, the G25 offers, with its lower output, a significantly more affordable base price as well as fuel economy of up to 20 mpg city, 29 highway—that's a mile or two per gallon better than the G37. For those who love the way the G37 looks and handles but don't need all the power, the G25 could be a very good deal.
For more information on the G25, see our full review of the Infiniti G Sedans.
