Closing a gap; Porsche Cayman moves closer to 911-for less money.(NEWS)

Byline: J. P. VETTRAINO

HOW'S THIS FOR AN AD SLOGAN? "Porsche 911 Carrera: A $15,400 back seat for really small people. \ Indeed, the new mid-engine Porsche Cayman S coupe is so good it makes the rear-engine 911 Carrera 2 almost superfluous, unless you actually need the parcel space that passes for the 911's rear seat. At the very least, the new Cayman makes the standard 911 seem a little overpriced. \ Known inside Porsche as the 987c Gen II, the 2009 Cayman S gets improvements similar to those introduced in the "09 Carreras: a more efficient, more powerful >>

engine, subtle updates inside and out and the optional PDK transmission, arguably the best auto-manual yet.

All of Porsche's 987 models, including the base Cayman and Boxster roadsters, get the Gen II treatment for "09. To date, however, Porsche has offered keys only to the Cayman S. Having reluctantly returned those keys, we conclude that Gen II further closes the performance gap between the upgraded Cayman and the base 911, to the point where there's really no gap at all.

Gen II engines all retain Porsche's familiar six-cylinder boxer configuration but have new bore and stroke dimensions. Displace-ment in the base engine increases from 2.7 liters to 2.9 liters; S models continue at 3.4 liters. The 3.4 is about 20 pounds lighter than its predecessor, with less reciprocating mass and higher maximum speed. Its bearings generate less friction, and its accessories draw less power. A variable-demand oil pump delivers more pressure at higher g loads but also reduces peak power demand and single-handedly cuts fuel consumption 2 percent.

The new engines also have direct fuel injection. An engine-driven fuel pump squirts gasoline directly into the combustion chambers at up to 1,750 psi, allowing for a 12.5:1 compression ratio that approaches stoichiometric nirvana and milks more power from less fuel.

The benefits are pronounced. The new Cayman S engine increases horsepower by 25 and torque by 22 lb-ft (to 320 hp at 7,200 rpm and 273 lb-ft at 4,750). It also reduces fuel consumption as much as 16 percent.