From 2001 to 2008, the 4.2-liter General Motors LL8 engine was manufactured at the Michigan facility and fitted to GMT360 platform vehicles like the Saab 9-7X, GMC Envoy, and Chevrolet Trailblazer. Although its consumption is high, this inline 6-cylinder engine is very dependable.

The Atlas family: LLV, LLR, LL8.
Specifications
| Production years | 2001-2008 |
| Displacement, cc | 4157 |
| Fuel system | distributed injection |
| Power output, hp | 270 – 295 |
| Torque output, Nm | 373 – 376 |
| Cylinder block | aluminum R6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 93 |
| Piston stroke, mm | 102 |
| Compression ratio | 10.0 – 10.3 |
| Features | DOHC |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | at the exhaust |
| Turbocharging | no |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 6.6 |
| Fuel type | petrol |
| Euro standards | EURO 2/3 |
| Fuel consumption, L/100 km (for GMC Envoy 2005) — city — highway — combined |
17.9 10.1 13.0 |
| Engine lifespan, km | ~400 000 |
| Weight, kg | 215 |
The engine was installed on:
- Buick Rainier 1 (GMT360) in 2003 – 2007;
- Chevrolet Trailblazer 1 (GMT360) in 2001 – 2008;
- GMC Envoy 2 (GMT360) in 2001 – 2008;
- Isuzu Ascender 1 (GMT360) in 2002 – 2008;
- Oldsmobile Bravada 3 (GMT360) in 2001 – 2004;
- Saab 9-7X 1 (GMT360) in 2004 – 2008.
Disadvantages of the GM LL8 engine
Due to sleeve subsidence, motors from the first year of production were recalled.
Other than that, it is a reasonably dependable device, but not everyone will enjoy using it.
You might notice chain stretching and valve seat wear after 200,000 kilometers.
The engine is concerned about overheating, and the fan’s viscous coupling serves comparatively little.
The exhaust manifold is another weak point; it frequently cracks.
