Comparing the projects of LiquidPiston to the Wankel engines is unavoidable, and of course Mazda is a major reference when it comes to rotary engines because of models such as the RX-7, not to mention all the aftermarket supports oriented mostly toward Mazda's 13B Wankel engine and its variations. As the Wankel fanbase goes beyond the old Mazda range, including many adaptations to which a compact size and high power-to-weight ratio of the 13B engine are a valuable asset, the opportunity for players such as LiquidPiston claiming to solve major handicaps of the Wankel design is clear, and eventually a better deal than relying solely on its contracts with the Department of Defense of the United States catering to the unmanned aerial vehicles (UAVs - a.k.a. drones) propulsion systems and portable in-field generator sets. Sure the deals with the military in the United States might be a comfortable source of funding for an engineering company, and a baptism-of-fire in a real battlefield may also be exploited for marketing purposes as a statement of reliability, yet it's pointless to forget other segments already consolidated.
As the Wankel engines are known to have the apex seals as their most critical aspect, and LiquidPiston claims its design solves most of the problem by placing the apex seals on the housings instead of on the rotors, a drop-in replacement engine suitable for the RX-7 and other models either fitted with a Mazda 13B engine from the factory or adapted with one usually for performance reasons. Most likely, as the claimed improvements on reliability and fuel-efficiency compared to both regular reciprocating engines and Wankels could be assessed in real-life conditions if LiquidPiston also decided to finally venture into a leisure-oriented application such as the worldwide Mazda rotary engine fanbase, many other segments to which the Wankel ultimately failed, there would be much better opportunities for an improved rotary engine for repowerings beyond a strictly performance-oriented market. And after some automakers tried to eliminate internal-combustion engines from their ranges due to all that political movements favoring electric vehicles, despite a massive backlash from customers who regretted buying electric cars for a tax break, there is another opportunity for LiquidPiston as many companies would ultimately outsource the engines in order to retain customers.
Sure the market for military engines is still very promising, and ultimately LiquidPiston benefitted from partial funding by DARPA (Defense Advanced Research Projects Agency), but it would still make more sense to venture into the civilian market which provides many opportunities which remain neglected by both major automakers and independent engine manufacturers in many different segments to which the compactness and higher power-to-weight ratio are much desirable. Placing all the eggs in a same basket is quite risky, and that's exactly what LiquidPiston does once it keeps far away from the Mazda Wankel fanbase and other applications to which its improved rotary engine projects may be more effective and commercially viable than a Wankel. And since the Mazda 13B engine which found its way into models such as the RX-7 was compact enough to be also easily adaptable into other models with an even more space-constrained engine bay, it's an obvious benchmark if LiquidPiston ever ventures into this field...
