Not that we didn’t likeCorp.’s “high-feature” 3.6L DOHC V-6 when it launched in the Cadillac CTS for the ’05 model year.
Its initial output was 255 hp and 255 lb.-ft. (346 Nm) of torque, and there were several competing similar-displacement V-6s already making in the neighborhood of 300 hp.
Although we sometimes find ourselves wishing everyone would dial back a bit on premium V-6 output, 300 hp is the new 250 hp, just like 60 years old is the new 40.
Thanks to a decade of horsepower wars, 300-hp V-6s now are the price of entry in the premium market.
To get fully in the game for the critical new ’08 Cadillac CTS (and to upgrade the larger standard engine on the STS), GM powertrain engineers looked to gasoline direct injection, a technology quickly sweeping through powertrain-development departments on several continents.
Strap on the high-pressure (1,740-psi/120-bar) GDI hardware and fair-to-middlin’ 255 hp becomes 304 horses. And just as important, torque also is boosted by about 8%.
Just like that, the new, direct-injected variant (internal code LLT) solves probably the most noticeable shortcoming of the original variable-valve-timing 3.6L DOHC V-6: the fizzy low- and midrange torque and resultant soft throttle response. The new GDI-equipped 3.6L V-6 has torque that gets your attention at any engine speed, and the throttle pedal no longer thinks rapidly increasing its proximity to the floor is a request that should be pondered at length.
“Solid midrange pull,” says Associate Editor Mike Sutton. “Just pulls and pulls,” echoes Best Engines judge Byron Pope.
And the 3.6L DOHC V-6 likes to pull to the redline, too, and running to the 6,400-rpm power peak is a pleasure to be repeated, underscoring how essentially right GM Powertrain engineers got the noise, vibration and harshness.
We did note – and others have mentioned it, too – a boomy, low-frequency thrum at low rpm. We hear engineers were aware of the matter and are working out a fix that already may be penciled in by the time you read this.
And as we’ve noted with the latest crop of high-performance V-6s, fuel economy is not a strong suit. Despite the fact GM says GDI improves brake-specific fuel consumption by 3%, the rated 17 mpg (13.8 L/100 km) city and 26 mpg (9 L/100 km) highway figures aren’t going to get anybody too far down the road toward the new 35-mpg (6.7 L/100 km) standard in 2020. A huge points-winner with us, however: The big power can be had using regular unleaded gasoline.
But we’re talking the here and now, and GM’s latest 3.6L DOHC V-6 is a world-class engine we’d stack up against any V-6 – and it adds serious credibility to Cadillac’s goal of reclaiming its reputation for technology leadership.
Ward’s 10 Best Engines is copyright Penton Media Inc. Commercial references to the program and/or awards are prohibited without prior permission of Ward’s Automotive Group.