Thank you for reading. Turbine engines have been used earlier by Chrysler. If throttle response is a reason they aren't prevalent there are many ways to reduce it. If I am not wrong, the compressor can have variable geometry vanes(similar to VGTs) and thereby reduce lag. I learnt that it is less fuel efficient..but it also said that any fuel can be used to combust the mixture and pass it on to the turbine. (not just petrol or diesel) There could be another a less expensive option to counter this inefficiency. Apart from this, can there be other reasons as well?