Three engine families cover most Commodores from the late 1990s on: the Ecotec 3.8 V6, the Alloytec 3.6 V6 and the LS-series V8. Getting the family right matters because parts rarely cross between them. This guide shows how to tell which one you have by series and features, then how to confirm it before ordering. To read the stamped number, see the Commodore engine number location guide.
Quick identification
| Engine | Capacity / layout | Series fitted | Tell-tale |
|---|---|---|---|
| Ecotec V6 | 3.8L pushrod V6 | VS–VZ | Iron block 3.8 V6; supercharged L67 on S/SS Supercharged variants. |
| Alloytec V6 | 3.6L DOHC V6 | VZ–VE (SIDI direct-injection on later VE) | Alloy block, double-overhead-cam 3.6; replaced the Ecotec from the VZ. |
| LS V8 | 5.7L / 6.0L / 6.2L V8 | VT (1999) onward; L76/L77/L98/LS2 in VE–VF, LS3 from 2015 | Pushrod alloy V8; the SS, SV6 (V6), Calais V and HSV models. |
Ecotec 3.8 V6 (VS–VZ)
The Ecotec is a 3.8-litre pushrod V6, an evolution of the earlier Buick-derived 3.8. It was the volume engine from the VS through to the VZ, with a supercharged L67 version in the Supercharged variants. If you have a 1995–2006 Commodore with an iron-block 3.8 V6, it is almost certainly an Ecotec. Parts for the Ecotec do not carry over to the later Alloytec.
Alloytec 3.6 V6 (VZ–VE)
The Alloytec is a 3.6-litre alloy, double-overhead-cam V6 that replaced the Ecotec from the VZ. It carried into the VE, where later builds used the direct-injection SIDI version. It is a very different engine from the Ecotec despite both being “the V6”, so cooling, ignition and ancillary parts are specific to it.
LS V8 (VT onward)
The LS-series V8 arrived in the VT in 1999 as the 5.7-litre LS1, replacing the older Holden 5.0. The VE and VF used 6.0-litre L76, L77 and L98 V8s, with the 6.2-litre LS3 offered from 2015. These are pushrod alloy V8s and are identified by their GM RPO code plus a stamped serial, not an old-style prefix.
How to confirm which engine you have
- Check the build/engine plate (radiator support on VT–VZ, passenger strut tower on VE–VF) for the engine code.
- Read the stamped engine number — see the location guide.
- The VIN and build codes confirm the original engine fitment — see the Commodore VIN number page.
- If an engine has been swapped, the physical engine number is the source of truth, not the VIN.
The 8th character of the VIN can hint at the engine on factory-original cars, but it varies by era, so treat it as orientation and confirm against the physical engine.