After all, the company has been packaging turbos in space-compromised engine bays for more than 20 years with huge success. And a turbo would cure two of the BRZ’s greatest vices: a lack of low-end torque and the need to spin its engine to 7000 rpm, where it’s thrashy and loud but still not especially powerful. So what did Subaru do?It persisted, boost-free.We give you the 2017 Subaru BRZ with a heavily revised but still naturally aspirated 2.0-liter flat-four. Equipped with new intake and exhaust manifolds, cylinder heads, cams, and valves, its power climbs from 200 to 205 horsepower while peak torque rises an equally insignificant 5 lb-ft, to 156 lb-ft. The gains appear so high in the rev range (peak output is at 7000 and 6400 rpm, respectively) as to be virtually imperceptible in daily driving. And the torque valley that haunts the BRZ’s midrange, between 3300 and 4600 rpm? It is slightly mitigated but still exists and is still burdensome. It’s a character killer in a car that’s otherwise full of promising personality.What’s more, these increases apply only to cars equipped with the six-speed manual transmission. The six-speed-automatic BRZ is rated, same as last year, at 200 horsepower and 151 lb-ft of torque. Stick-shift BRZs also benefit from a shorter final-drive ratio (4.30:1 versus 4.10:1) that gives the low-torque engine better leverage over the tires.Predictably, a 5-hp gain and marginally shorter gearing do little to improve measured performance. Our 2017 test car hit 60 mph in 6.2 seconds and covered the quarter-mile in 14.8 seconds—improvements of 0.1 second across the board relative to the last manual BRZ we tested, a 2016 model. Trap speed remained the same at 95 mph. That slight boost in straight-line performance also comes with a penalty at the pump, with the manual BRZ now EPA rated at 21 mpg city and 28 mpg highway, down from last year’s 22/30 mpg. We weren’t able to record a real-world figure for this BRZ, but a similar 2017 Toyota 86 we tested at the same time returned a 23-mpg average.Stiffening at the front strut mounts and rear damper mounts, coupled with retuned spring rates plus a larger rear anti-roll bar, yield only subtle improvements in road driving. Even at the BRZ’s limits, most drivers would find the changes every bit as hard to detect as that tenth of a second in the quarter-mile. Even so, the Subaru’s steering response, overall balance, and compact packaging encourage hard driving in ways that other coupes at this price simply do not. At 0.90 g on the skidpad, the BRZ doesn’t break any grip records. Blame the modest 215/45R-17 Michelin Primacy HP rubber, not the chassis, which boasts frustratingly underutilized potential.Our test car lacked the $1195 Performance package, which adds Brembo four-piston front and two-piston rear calipers in addition to larger rotors at both ends. The standard brakes stopped the car in 164 feet from 70 mph, nearly identical to the previous BRZ.At this rate, the BRZ and its counterpart, the Toyota 86, are destined to suffer the same fate as the late Nissan 240SX—another coupe with a fantastic chassis that desperately needed an engine to match. The Nissan died at the hands of bean counters disgruntled about low sales volume. The benefits a turbocharged engine would bestow on the BRZ are too great to ignore, both for driving enthusiasts and for its longevity. Are you listening, Subaru?