whats the difference

[bjl8691]

just bought a murray push mower with a 450 briggs last week for 150 at walmart
they had a few murray mowers 1 had a 300 series briggs and the other had a 450 series briggs both look identical and had the same specs listed whats the difference between a 300 and 450 series briggs motor?

 

[ILENGINE]

The 300 has 3.00 ft/lb of torque, the 450 has 4.50 ft/lb of torque. More torque more work it can do without overloading the engine