ORIGINAL: piper_chuck

It's because there is more to an engine purchase than price. The OS .45 AX or 50 SX have more power and are lighter than similar sized Super Tigre engines. Reputation and experience also comes into play when making the decision. I've had engines from both companies. My OS engines have always been super reliable, easy to tune, and have never given me trouble. My Super Tigres have been significantly less reliable, and are not as simple to setup. I've either sold them off or put them back in the box because they were just too much trouble.