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CATEGORIES (articles) > Engines > Chevy Engines > GM Premium V Northstar engine

GM Premium V Northstar engine

GM Premium V
Manufacturer: General Motorsz M113 engine|Mercedes-Benz M113/M115]]
BMW M62/S62
Toyota UZ
Nissan VH
Nissan VK|
Similar:Jaguar AJ-V8
Ford Modular V8
Ford/Yamaha V8
Chrysler PowerTech V8
Mercedes-Benz M113/M115
BMW M62/S62
Toyota UZ
Nissan VH
Nissan VK

The Premium V family of automobile engines is General Motors' modern 90° v engine architecture. The family is most associated with Cadillac's Northstar V8, but the family has also seen use at Oldsmobile (as the Aurora L47 V8 and "Shortstar" LX5). The Oldsmobile variants are no longer in production, but the Northstar family has expanded with new longitudinal and 4.4 L supercharged versions. The Northstar name is now used outside Cadillac as well, with the Pontiac and Buick versions now carrying that moniker. Alfa Romeo is rumored to be another future user of the Premium V in the US-market Kamal.

Development and features

The Premium V design was initiated as a response to the advanced dual overhead cam V8 engines introduced by Cadillac's European and Japanese competitors in the late 1980s. At that time, Cadillac was using the aluminum HT family overhead valve V8 with pushrods which had been pushed hastily into production after the failure of the V8-6-4 of 1981.

Cadillac was developing new models like the Allanté and updated Eldorado and Seville STS which they hoped would compete against the best from BMW, Mercedes-Benz, Lexus, and Infiniti. They developed a laundry list of items that must be included in these new models, including sophisticated steering, braking, and suspension technologies, which became known as the Northstar System. One key element was a high-tech V8 engine with all of the features and performance of the competitors' offerings.

The "Northstar" V8, as it was then known, was to be an all-aluminum DOHC 32-valve V8 which was capable of producing 300 hp (224 kW). Archrival Ford Motor Company was developing a similar engine at that time as well, and Ford's Modular engine would follow the Northstar into production one year later. Both continue in production at 4.6 L of displacement.

The Northstar featured a unique die-cast aluminum 90° V8 block with 102 mm (4 in) bore spacing split into unitary upper and lower halves. The lower crankcase assembly supported the crankshaft without conventional main bearing caps. An oil manifold plate with an integrated silicon gasket forms the oil gallery under this.

Cast-iron cylinder liners were specified, sparing Cadillac from the Nikasil fiasco. The forged aluminum pistons included valve clearance, making Northstar a non-interference engine, with bronze pin bushings and free-floating piston pins used.

The one-piece cast aluminum cylinder heads extend around the "maintenance-free" cam-drive chain case. Direct-acting hydraulic valves are used with a lubrication passage drilled through the cylinder head lengthwise. The intake valves are inclined at 25°, while the exhaust valves are canted to 7° with center-mounted platinum-tipped spark plugs. The cam covers were fabricated from magnesium for light weight.

Eight thermoplastic tubes were used in the induction system, leading to sequential fuel injection. Direct ignition was a novelty for the time, with an electronic system adjusting spark and fuel injection timing as well as the shift points for the new 4T80-E transmission.

One notable feature, advertised at the time, was the fail-safe cooling mode which allowed the engine to continue running for a limited time without any coolant at all. It alternated banks of cylinders to maintain cool temperatures, allowing a Northstar-equipped car to be driven with no coolant for about 100 mi (161 km) with no damage.

All engines of this family share the same Northstar bellhousing pattern.

Later developments included variable valve timing, which can vary intake by up to 40° and the exhaust by up to 50°. First introduced in the longitudinal LH2 version, this system later spread to all Northstars.


The engine was introduced in mid-1992 in the 1993 Cadillac Allanté and continues to be used in most Cadillac models. The original Northstar Allanté also introduced the Northstar System which included traction control, adaptive suspension, and antilock brakes.

The Northstar was sold exclusively by Cadillac for over a decade before being introduced in the 2004 Pontiac Bonneville and 2006 Buick Lucerne. However, the L47 V8 variant was used in the Oldsmobile Aurora and the 3500 LX5 V6 in the Oldsmobile Intrigue. The engine received a forged steel crankshaft in 2003. Cadillac is said to be planning to introduce a V12 Northstar this decade, likely for use in the Escalade.

Most Northstar engines produce 275 to 315 hp (205 to 235 kW). The engines were revised for 2000 with variable valve timing for improved fuel economy and reduced emissions, though power output did not change.

All but the supercharged Northstar displace 4.6 L (4645 cc/283 in³) with a 93 mm (3.66 in) bore and 84 mm (3.31 in) stroke. The supercharged version is de-bored to 91 mm (3.6 in) for a total displacement of 4.4 L (4371 cc/266 in³). The block is said to be capable of expansion up to 5.4 L, though no such engine has been produced.

The Northstar was on the Ward's 10 Best Engines list for 1995 and 1996.


The L37 was the original Northstar. It is tuned for responsiveness and power, while the later LD8 is designed for more sedate use. The L37 code has been used on all high-output transverse Northstars, even as the exact engine specifications evolved.

The original L37 was specified at 290 hp (216 kW), but 1993 production examples were rated at 295 hp (220 kW). The engine topped out at 300 hp (224 kW) from 1996 through 2002 on the STS and ETC models, making these some of the most powerful front wheel drive cars ever built, the most powerful title still belonging to the 1970 Cadillac Eldorado with 400 hp (500 in³, 8.2 L).

A revised high-output L37 will be used in the 2006 Cadillac DTS Performance version. It produces 291 hp (217 kW).

Vehicles using the L37 include:
1993Cadillac Allanté295 hp (220 kW)290 ft·lbf (393 N·m)
1994Cadillac Eldorado ETC295 hp (220 kW)290 ft·lbf (393 N·m)
1995–2002Cadillac Eldorado ETC300 hp (224 kW) at 6000 rpm295 ft·lbf (400 N·m) at 4400 rpm
1993Cadillac Seville STS295 hp (220 kW)290 ft·lbf (393 N·m)
1994–2004Cadillac Seville STS300 hp (224 kW) at 6000 rpm295 ft·lbf (400 N·m) at 4400 rpm
1996–2004Cadillac DeVille Concours300 hp (224 kW) at 6000 rpm295 ft·lbf (400 N·m) at 4400 rpm
2005Cadillac DeVille Concours290 hp (216 kW) at 5600 rpm285 ft·lbf (386 N·m) at 4400 rpm
2006–Cadillac DTS Performance292 hp (218 kW) at 6300 rpm288 ft·lbf (390 N·m) at 4500 rpm


The LD8 is a transverse V8 for front-wheel drive cars. Introduced in 1994, it is designed to provide more torque than the high-revving L37. The LD8 code has been used on all torque-tuned transverse Northstars, even as the exact engine specifications evolved.

The 1998 revision is quieter (thanks to hydraulic engine mounts) and performs better (thanks to a tuned intake system) than previous Northstars.

Most LD8 Northstars are rated at 275 hp (205 kW) and 300 ft·lbf (407 N·m).
1994Cadillac Eldorado270 hp (201 kW)300 ft·lbf (407 N·m)
1995–2001Cadillac Eldorado275 hp (205 kW) at 5750 rpm300 ft·lbf (407 N·m)
2002Cadillac Eldorado275 hp (205 kW) at 5600 rpm300 ft·lbf (407 N·m) at 4000 rpm
1994Cadillac Seville SLS270 hp (201 kW)300 ft·lbf (407 N·m)
1995–2001Cadillac Seville SLS275 hp (205 kW)275 ft·lbf (373 N·m)
2002–2004Cadillac Seville SLS275 hp (205 kW)300 ft·lbf (407 N·m)
1994Cadillac DeVille Concours270 hp (201 kW)300 ft·lbf (407 N·m)
1995Cadillac DeVille Concours275 hp (205 kW) at 5750 rpm300 ft·lbf (407 N·m)
1996–2001Cadillac DeVille275 hp (205 kW) at 5750 rpm300 ft·lbf (407 N·m)
2002–2005Cadillac DeVille275 hp (205 kW) at 5600 rpm300 ft·lbf (407 N·m) at 4000 rpm
2006–Cadillac DTS275 hp (205 kW) at 6000 rpm295 ft·lbf (400 N·m) at 4400 rpm
2004–2005Pontiac Bonneville GXP275 hp (205 kW) at 5600 rpm300 ft·lbf (407 N·m) at 4000 rpm
2006–Buick Lucerne CXS275 hp (205 kW) at 6000 rpm295 ft·lbf (400 N·m) at 4400 rpm


The Northstar was designed originally for transverse front-wheel drive applications. It was modified substantially in 2004 for longitudinal rear- and all-wheel drive use in the SRX and XLR. The RWD (LH2) Northstar is good for 315–320 hp (235–239 kW) and 310–315 ft·lbf (420–427 N·m).
2004–Cadillac SRX320 hp (239 kW) at 6400 rpm315 ft·lbf (427 N·m) at 4400 rpm
2004–Cadillac XLR320 hp (239 kW) at 6400 rpm310 ft·lbf (420 N·m) at 4400 rpm
2004–Cadillac STS320 hp (239 kW) at 6400 rpm315 ft·lbf (427 N·m) at 4400 rpm


A 4.4 L (4371 cc/266 in³) supercharged Northstar is used in the 2006 Cadillac STS-V and Cadillac XLR-V. The bore was reduced for increased strength. Variable valve timing is used on both the intake and exhaust sides. The STS-V engine produces 469 hp (350 kW) at 6400 rpm and 439 ft·lbf (595 N·m) at 3900 rpm with 9.0:1 compression and the XLR-V engine produces 443 hp (330 kW) at 6400 rpm and 414 ft·lbf (561 N·m) at 3900 rpm .
2006–Cadillac STS-V469 hp (350 kW) at 6400 rpm439 ft·lbf (595 N·m) at 3900 rpm
2006–Cadillac XLR-V443 hp (330 kW) at 6400 rpm414 ft·lbf (561 N·m) at 3900 rpm


A L47 inside an Aurora's engine bay
L47 Aurora engine was a special V8 designed for the Oldsmobile Aurora, based on the Northstar engine. It is a DOHC 4.0 L (3995 cc) V8 which produced 250 horsepower (186 kW) and 260 ft·lbf (353 N·m) of torque. The bore is 87 mm and the stroke is 84 mm. The L47 has a 10.3:1 compression ratio and uses premium fuel.

Although most of the Northstar's features, including the coolant loss system, remained intact, the decreased bore increased weight unacceptably. To reduce it, Oldsmobile used a one-piece glass-filled thermoplastic intake manifold and simplified AC Rochester sequential fuel injection. A new die-cast structural aluminum oil pan incorporated baffling to reduce oil starvation in hard driving. A starter interlock prevents the starter from engaging if the quiet L47 is already running.

A special version of this engine was used as one of the two engines available to Indy Racing League competitors at the inception of that automobile racing promotion (the other engine was a modified Infiniti Q45 V8 from Nissan).

The Aurora engine was introduced in 1994 for the 1995 model year, and General Motors has not used this engine since the demise of the marque in 2004.


A Shortstar inside an Intrigue's engine bay

The 3500 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 4 valves per cylinder, but is an even-firing design with a split-pin crankshaft similar to the modern GM 3800 engines. The LX5 displaced 3.5 L (3473 cc) and produced 215 hp (160 kW) and 230 ft·lbf (312 N·m). Bore is 89.5 mm and stroke is 92 mm.

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. It was entirely different from any other V6 in the GM inventory, and as with the Aurora V8, production stopped with the demise of Oldsmobile.

This engine was used in the following:

  • 1999-2002 Oldsmobile Intrigue
  • 2001-2002 Oldsmobile Aurora
The 3500 LX5 was on the Ward's 10 Best Engines list for 1999 and 2000.

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