Northstar Engine Series - LX5 (Shortstar)

LX5 (Shortstar)

The LX5 V6 is a DOHC engine from Oldsmobile, introduced in 1999 with the Oldsmobile Intrigue. It was produced by the Premium engine group at GM and was thus called the Premium V6, or PV6, while it was being developed. It is based on the L47 Aurora V8, which is itself based on the Northstar engine, so engineers called it the Short North, though Oldsmobile fans have taken to calling it the Shortstar.

It is not a simple cut-down V8. Although it has a 90° vee-angle like the Northstar and Aurora, the engine block was engineered from scratch, so bore centers are different. It has chain-driven dual overhead cams and four valves per cylinder, but is an even-firing design with a split-pin crankshaft similar to the Buick 3800 engine. The LX5 displaced 3,473 cc (3.473 L; 211.9 cu in) and produced 215 hp (160 kW) @ 5,600 rpm and 234 lb·ft (312 N·m) @ 4,400 rpm. Bore is 89.5 mm (3.52 in) and stroke is 92 mm (3.6 in). It was also one of GM's first engines to use coil-on-plug ignition. Compression ratio is 9.3:1.

The cost of building this engine was high, and it was not used in many vehicles. It was said at the time that a family of premium V6s would follow, with displacements ranging from 3.3 L to 3.7 L, but only the LX5 was ever produced before GM axed the Shortstar in favor of their current flagship V6, the High Feature, in 2004.

The LX5 was entirely different from any other V6 in the GM inventory - the only other DOHC V6 engines ever offered by GM include the troublesome-to-maintain Chevrolet Twin Dual Cam produced from 1991-1997 (which was made by heavily modifying the traditional Chevy 60-degree OHV block for the dual overhead cams rather than building a DOHC engine from the ground up), and the Cadillac/Holden HFV6 available from 2004 to the present day. These three designs are completely unrelated and oddly enough leave two gaps in 1998 and 2003 where no DOHC V6 was available from GM. (Except for the 54 degree Opel V6 used most notably in the first generation Cadillac CTS at launch as well as the Saturn L Series.) This contrasts starkly with competitors practices of evolving engineering over multiple, continuously improving designs.

As with the Aurora V8, production stopped with the demise of Oldsmobile.

The 3.5L LX5 was on the Ward's 10 Best Engines list for 1999 and 2000.