Men lie, women lie, numbers don’t

It has been said that numbers don’t lie. Statistics can be manipulated, polls can be interpreted, but power output is what it is.

One of the most common methods to measure a vehicle’s power output is by using a chassis dynomometer. The dynomometer or dyno has rollers that apply resistance to measure the amount of force applied by the front, rear, or all four wheels.

In 1971, auto manufacturers in the U.S. changed how they reported engine power. They previously published gross horsepower ratings. Gross hp is an engine rating with no accessories, belts, or pulleys drawing power from the motor. Current vehicles are rated using net horsepower. This method includes the accessories in the ratings.

For example, in 1972, an Oldsmobile Cutlass with 350 cubic inch V8, 2 barrel carburetor, and single exhaust was rated at 165 net horsepower. The same motor with dual exhaust was rated at 180 hp. This measurement is at the engine. The amount of power that makes it through the transmission, driveshaft, and differential to the wheels is less.

I took my 1972 Oldsmobile Cutlass to Crucial Performance to do baseline runs on their DynoJet dyno. The car has a 355 cubic inch Oldsmobile small block. The car has a mild cam and othe performance upgrades. A complete list of engine modifications can be found in the 72 Cutlass Engine Specs post.

The dyno session consisted of 3 pulls in third gear with the dynomometer measuring engine speed, mph, and air/fuel ratios against the horsepower and torque graph. 

The end result. To say I was disappointed would be an understatement. The setup produced 209 hp and 275 tq. I was hoping to be closer to 300 hp. I’m not sure why that is the magic number, but it seems to be the modern threshold for performance vehicles. 

On the bright side, the air/fuel numbers were spot on. Especially impressive, for a carbureted, flat tappet, old school motor. It may not be a big numbers car, but it is a fun and reliable driver that looks and sounds good. I will try not to be so down on the old girl.


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