Complex sentence: Limited batches of 115/145, commonly called Avgas 115, are produced for special events, such as unlimited air races; in the past 115/145 was used as the primary fuel for the largest, boost-supercharged radial engines that needed this fuel's anti-detonation properties.
Split into simpler sentences: Limited batches of 115/145, commonly called Avgas 115, are produced for special events, such as unlimited air races. In the past, 115/145 was used as the primary fuel for the largest, boost-supercharged radial engines that needed this fuel's anti-detonation properties.