Pros : Satisfies roadster cravings Great inline-six Soft top > hard top Cons : Sticker shock Muddled design Stressed turbo-four BMW s all-new Z4 roadster enjoys a heritage that dates to 1956 in the gorgeous BMW 507. Beginning officially with the low-volume Z1 in 1989 and skipping right over the nonexistent Z2, the Z models began in earnest with the 1995 Z3. Then came the much larger V-8-powered Z8 showstopper, then back to the Z4, and so on. So, is this the third-generation Z4 or sixth-gen Z model? Its your call. Regardless, BMW cant seem to shake the allure of an intimate top-down driving experience. Read about Car, SUV, and Truck of the Year contenders HERE . The key question: Is the Z4 a success? It takes a special talent to make a front-engine, rear-drive, two-seat roadster look like it was built on a proletarian front-drive platform, international bureau chief Angus MacKenzie said, always to the point. But somehow BMW has pulled it off. The Z4s proportions are remarkably dowdy for a sports car. Ouch. Not that everyone felt that way. --> Oddly, BMW sent us a 2019 Z4 sDrive30i and a 2020 Z4 M40i. Build dates aside, its remarkable how differently these two convertibles drive and how divided our judges felt about the merits or deficiencies of each. Powering the Z4 sDrive30i is the new-ish B48 2.0-liter turbocharged inline-four, which makes an enticing 255 horsepower and a stout 295 lb-ft of torque from a low 1,500 rpm. Thats good enough for a 060 blast in just over 5 seconds and an impressive 100-mph trap speed in the quarter mile. The more muscular Z4 M40i gets an also recently updated engine with the B58 3.0-liter turbocharged inline-six, making 382 horsepower and 369 lb-ft of torque. That earns it a sub-4-second 060 time as well as a sub-13 quarter mile. This little car punches well above its weight, which is more than we could say for the prior Z4. Read our Z4 vs. Supra comparison right here . Objective numbers are one thing, but our judges subjective opinions were harder to parse. I rather liked the four-cylinder version. I felt like this engine is stressed in the 3 Series but right-sized in the Z4. Its torquey at the bottom and bright at the top. The 30is cohesiveness works better than the M40i, which feels like its trying too hard to be taken as a serious sports car. But MacKenzie felt that even in the lighter Z4, the turbo-four didnt have the sparkle BMW needs for such a car. Then editor-in-chief Ed Loh muddied the water: Good amount of power initially, but then it feels a bit lacking when you get into the really tight stuff. Its often caught out of gear or just down on power. Were we driving the same car? As for the M40i, things were just as unclear. Loh was effusive: Drift machine! Very controllable and fun to drive. Lovely-sounding engine and great brakes with excellent pedal feel and initial response. To which technical director Frank Markus sniped: This feels like a short-wheelbase 3 Series with too many of the 3s problems: bad brakes, pogoing, etc. I found the BMWs Sport+ calibration to be a bit more conservative than the Supras Sport setting, in that to get a bit of a slide here and there I had to apply more aggressive trail-braking and/or more abrupt throttle inputs. Everyone agreed that the pricing was a challenge. With the Z4 sDrive30i starting at $50,695 ($62,845 as tested) and the Z4 M40is base price of $64,695 ($73,295 as tested), is the six-cylinder engine really $14,000 better? Or as Loh put it, I can see how one could prefer the Z4 M40i over the mechanically related Supra, until you see the price. As it sits, its $20,000 more than the Supra but not $20,000 better to drive. BMW Z4 2019 sDrive30i 2020 M40i Base Price/As Tested* $50,695/$63,545 $64,695/$73,295 Power (SAE net) 255 hp @ 5,000 rpm 382 hp @ 5,000 rpm Torque (SAE net) 295 lb-ft @ 1,500 rpm 368 lb-ft @ 1,600 rpm Accel, 0-60 mph 5.2 sec 3.9 sec Quarter Mile 13.8 sec @ 100.7 mph 12.4 sec @ 112.0 mph Braking, 60-0 mph 99 ft 101 ft Lateral Acceleration 1.02 g (avg) 1.02 g (avg) MT Figure Eight 24.5 sec @ 0.79 g (avg) 24.0 sec @ 0.84 g (avg) EPA City/Hwy/Comb 25/32/28 mpg 24/31/26 mpg The post From 507 to Z4: We Review Both BMW Z4 Models appeared first on MotorTrend .