It's one thing for a highly-boosted four cylinder to live under the hood of an Evo or STI, but it's quite another when you find one in a mainstream family sedan like the 2011 Hyundai Sonata 2.0T.
Heck, Hyundai even goes one step further down the path of convention and offers its intercooled 2.0-liter turbo mill as simply an engine option in the Sonata and not in some special loony, high-strung performance variant. Hyundai intends the turbo four as a V6 replacement. This implies that the turbo engine's power delivery is suited even for non-enthusiast drivers in everyday driving conditions.
But what happens when you give it the beans? We aimed to find out, and so we coerced the boosted Hyundai Sonata 2.0T onto the dyno at MD Automotive in Westminster, CA.
While Hyundai rates the engine's 274 horsepower and 269 lb-ft of torque (as measured at the flywheel) on 87 octane, the company's powertrain engineers tell us that 93 octane allows for the production of about ten additional horsepower and no change in peak torque. Our car had 91 octane in the tank, so interpolating suggests that our car has about 6-8 horsepower more than its rating, or a total of 280-282 hp the flywheel.
At the wheels, we measured its output thusly:
Peak torque of 239 lb-ft arrives at 3500 rpm, and the power peak of 234 horsepower is reached at 6100 rpm. That dip in the torque curve centered at 3900 rpm was consistent pull after pull and suggests that boost briefly spikes at 3500 before subsequently settling down a bit. Based on other cars we've dynoed here, peak power is a hair lower than we'd have expected based on the flywheel rating. Then again, there is a power-sucking autobox transmission involved so keep that in mind. Heat soak was not a factor here as the car was quite consistent from pull to pull.
Fourth gear was used in these runs. Like in the Mazdaspeed 3, torque in gears lower than this is electronically limited to prevent torque steer. That's another reason to love rear wheel drive layouts, as if you needed one. Also, wide open throttle was applied below 2000 rpm but the data starts at around 2500 rpm due to the the automatic transmission's torque converter lockup characteristics.
Hey, are you curious how this engine stacks up to the normally aspirated Sonata? I was. So I dynoed our longterm 2011 Hyundai Sonata GLS too. Here's the comparison:
Peak numbers for the normally aspirated 2.4-liter Sonata GLS (198 hp and 184 lb-ft at the flywheel) were as follows:
167 hp at 5950 rpm
169 lb-ft at 4950 rpm
So, the dyno suggests that the difference between the two power plants is about 67 horsepower and 70 lb-ft. We expected a bit more of a difference at peak power based on the two engines' flywheel ratings.
With the way the turbo engine's torque rises at low engine speed, you'd think the 2.0T is a somewhat laggy turbo implementation. In reality, it is not. Part throttle transient response from the engine is excellent, and the torque ramp observed in the dyno result is not characteristic of how snappy it feels in the real world.
One factor here is that an inertia dyno like the Dynojet we used does not load the car exactly as in the real world, which messes with transient phenomena like boost response (and the resulting torque ramp). On the other hand, Hyundai's claim of peak torque available from as low as 1800 rpm doesn't consider that the engine is bolted to a torque converter that isn't locked up at 1800 rpm. Thus, when out on the road, the engine speed at which the 2.0T's peak torque arrives lies somewhere between these two extremes.
Access to the engine's torque at part throttle is arguably more important in a family sedan like the Sonata than a few horsepower out near redline. In the real world, the 2.0T drives quite sharply and the transition into boost is immediate and seamless irrespective of where the tach needle points. Still, I'm curious as to where a few ponies wandered off.