This provides a bit more interior room, especially in the back seat of the GS where headroom now measures 37.8 inches, which is about on par with the back seat of the M37. Legroom in the GS 350 back seat totals 36.3 inches, or about the same as the M37. Still, there's a hump in the GS rear floor that a middle passenger has to contend with, and three adults sit closely in back. Trunk space of 14.3 cubic feet is accommodating.
Passengers familiar with more refined rides in Lexus cars were surprised to hear the strong, throaty engine sounds from the test GS 350 F Sport. They also didn't know what to make of the ride that readily conveyed road vibrations, even when the suspension setting was in normal mode.
The 3.5-liter, double overhead cam, direct gasoline injection V-6 is mildly tweaked from last year for peak torque of 277 foot-pounds at 4,800 rpm.
Power came smoothly and quickly through a six-speed automatic transmission, and zero-to-60-miles-per-hour time is a sporty 5.7 seconds, according to Lexus.
But enjoying the GS 350's torquey "oomph" at startups and around slower cars took a toll on fuel mileage, as the tester averaged just under 20 miles per gallon in combined city/highway travel.
The federal government's fuel economy rating for the 2013 GS 350 is 19 mpg in city driving and 26 mpg on the highway.
In comparison, the base 5-Series with turbo four cylinder generates a healthy 260 foot-pounds, just 17 shy of the GS, and it comes on starting at a low 1,250 rpm while earning a government fuel mileage rating of 23/34 mpg.
Note that premium gasoline goes into the GS, which at today's prices meant a fillup of the 17.4-gallon tank in the tester came to more than $72 for about 365 miles of travel.
The GS six-gear transmission seems a bit dated when compared with the 5-Series' standard eight-gear automatic, and the M37's seven speed.
Steering in the GS 350 tester was crisp and precise, requiring virtually no adjustments in long sweeping curves.
Be aware that the top-of-the-line, sport-tuned GS 350 with F Sport package is pricey, especially when packaged as it was in the tester with other items for more than $13,000.