low-compression engine

Natural gas has an octane rating of 120, but this property has little value in a low-compression engine.

Natural gasoline has an octane rating of about 30 to 50, sufficient for the low-compression engines of the early 20th century.

The low-compression engine meant it was able to run on "2-star" low-octane petrol, which was cheaper than varieties used by larger and more highly tuned engines.

Tamed down by low-compression engines, sales of the ragtop GTO dwindled, but low production volume translates to higher prices today.

The Express was equipped with the low-compression engine used in the Standard Minx and had the model designations PT100/200/300.

Most of these applicable aircraft have low-compression engines which were originally certified to run on 80/87 avgas and require only "regular" 87 anti-knock index automotive gasoline.

Automakers in the U.S. switched from gross to net power and torque ratings in 1972 (coinciding with the introduction of low-compression engines); thus, it is difficult to compare power and torque ratings between 1971 and 1972.