A relative recently sold her 2000 Infiniti I30t, which had 227 horsepower. Her replacement, a 2010 Volkswagen Jetta TDI, has a mere 140 hp. Though both cars weigh nearly the same, she claims her new VW is "more powerful" than the Infiniti. A 2000 "Motor Trend" test of the I30t yielded a zero-to-60-mph sprint of 8.4 seconds; the same magazine recorded 8.4 seconds for a Jetta TDI last year.
In a word, torque. It's the stuff that rockets you away from the stoplight and shoves you into your seat. The Jetta TDI has 236 pound-feet of it at 1,750 rpm, just above idle speed. Her Infiniti I30t had 217 lb-ft at a much higher 4,000 rpm. Lots of low-end torque gives a relaxed, effortless feeling of thrust from the moment the accelerator is pushed.
When trying with all your might to open the top of a new jar of mayo, torque is present even if movement isn't. It's pure twisting force. Horsepower, on the other hand, requires movement to exist. A hand with lots of horsepower could spin the lid rapidly once it's loose, but without much torque, that lid might never budge.
Torque is the stuff that rockets you away from the stoplight and shoves you into your seat. Turbodiesel engines, like the one in the 2010 Jetta TDI, are legendary for generating lots of low-end torque even in small, efficient packages. Turbocharged gasoline engines, especially newer direct-injected versions like VW/Audi's 2.0T and Ford's EcoBoost engines (Flex, Taurus SHO, Lincoln MKT), are also known for giving good twist down low, and these gasoline designs also pack a wallop of horsepower up high. Massive V8, V10 and V12 engines make great torque, but guzzle gasoline in the process. Electric motors take the cake, always producing maximum torque even at a dead rest and giving vehicles like Tesla's Roadster breathtaking acceleration.
An example of an engine with high horsepower but little torque is the Honda Civic Si. Its 2.0-liter four-cylinder makes an impressive 197 hp, but just 139 lb-ft of torque. It feels much like an ordinary, peppy sedan at low and medium engine speeds, even a tad sluggish with a full load and the air conditioning on. However, as engine speeds climb, the Civic Si begins waking up, finally delivering a thrill that culminates in its peak power at a lofty (some might say buzzy) 7,800 rpm. Most drivers simply don't spend much time – if any – revving their engines to the upper reaches of the rev counter, where big horsepower usually lives.
Next time you take a car for a test drive, put some torque in your talk. Ask the dealer how much it has, and if it occurs nice and low. You'll probably send him to the spec sheet and perhaps gain the upper hand on a sweet deal.