Like God and Congress, Car and Driver sometimes moves in mysterious ways. Which perhaps explains why the initial 2008 Cadillac CTS we tested was powered by the optional 304-hp direct-injection (DI) V-6, after which we moved to the monster 550-horse CTS-V. And now—ta-da!—we revert to the starter-kit CTS, powered by an alloy 263-hp, 3.6-liter V-6 with port fuel injection and variable valve timing. Should we have begun here?
Because this is a tale of two engines, let us turn straight to the numbers. Compared with the DI, the base V-6 propels the CTS to 30 mph in an identical 2.2 seconds. To 60 mph, it’s only 0.4 second behind, and through the quarter-mile it’s but 0.3 second and 3 mph in arrears. Driving the base and DI cars back-to-back, what you’ll notice is the more powerful engine’s half-second edge in 30-to-50-mph passing maneuvers. You’ll also occasionally summon a two-gear kickdown where the stronger engine begs for only one, and the DI’s tail is easier to rotate before the StabiliTrak intervenes.
The base V-6 emits a charming growl right to its 7000-rpm redline. At full whack, it is 2 dBA noisier than the DI. On the other hand, it’s quieter at idle and at a 70-mph cruise. Both engines offer smooth throttle tip-in and excellent idle quality.
Around town, the base V-6 earns a bonus 1 mpg but merely matches the DI’s highway economy. In our hands, a test car delivered an observed 23 mpg.
A “stripper” CTS with only the $1300 Hydra-Matic six-speed automatic, which includes a gloriously efficient manumatic, is $34,790. The DI costs an extra $1000. Because more power is always C/D’s mantra, we’d somehow locate the loot for the bonus 41 ponies. For 90 percent of daily driving, however, these two sedans behave like fraternal twins. GM could really simplify matters by making the DI standard. But the truth is, either of the V-6 CTSs—in terms of engineering, value, and dynamic charm—likely represent the finest effort in Cadillac’s 106-year history.