Mercedes-Benz M273 engine

{{Infobox automobile engine

|name=Mercedes-Benz M273

|image=M273 TMS2005 01.JPG

|manufacturer=Mercedes-Benz

|production=2005–2013

|configuration=Naturally aspirated 90° V8

|valvetrain=DOHC 4 valves x cyl. and continuous VVT

|predecessor=Mercedes-Benz M113

|successor=Mercedes-Benz M278

|fueltype=Gasoline

|fuelsystem = Sequential port injection

|coolingsystem=Water cooled

|block=Aluminium

|head=Aluminium

|displacement={{convert|4663|cc|L|1|abbr=on|disp=flip}}
{{convert|5461|cc|L|1|abbr=on|disp=flip}}

|bore={{convert|92.9|mm|2|abbr=on}}
{{convert|98|mm|2|abbr=on}}

|stroke={{convert|86|mm|2|abbr=on}}
{{convert|90.5|mm|2|abbr=on}}

|power={{convert|250-285|kW|PS hp|0|abbr=on}}

|torque={{convert|460-530|Nm|lbft|0|abbr=on}}

}}

The Mercedes-Benz M273 engine is a V8 automobile piston engine family used in the 2000s (decade). It was based on the similar M272 V6 introduced in 2004.

An evolution of the M113 V8,{{Cite web|url=http://australiancar.reviews/mercedesbenz_M273.php|title=Mercedes-Benz M273 engine|website=australiancar.reviews|language=en|access-date=2018-06-17}} all M273s have aluminium engine blocks, sequential port fuel injection, fracture-split forged steel connecting rods, a one-piece cast crankshaft, and a magnesium intake manifold. The cylinders are lined with silicon/aluminium, and a dual-length variable-length intake manifold is fitted.{{cite web | url=https://www.motorreviewer.com/engine.php?engine_id=174 | title=M273 5.5/4.7L Engine - In-Depth Look at Design and Reliability }}

In addition to this, new features shared with the M272 include DOHC aluminium cylinder heads, 4 valves per cylinder and independent continuously variable valve timing on both the intake and exhaust sides.

A new electronically controlled cooling system has eliminated the need for a mechanical thermostat for improved engine warm-up and optimum control of engine temperature.