One problem related to engine shut off without warning has been reported for the 2005 Mazda RX8. The most recently reported issues are listed below.
There is a flaw in the Mazda Rx8 engine. It is why they stopped making them in 2011. The engines have bad apex seals. As a result - the seals blow around 70 thousand miles and the engine is useless. Mazda replaced my engine in 2011. However - it does not solve the problem. The engine still shuts down in traffic. This is extremely dangerous. When you are coming to a stop or slowing down the engine will just shut off. It has also shut off when I attempted to pass in the left lane while accelerating on the highway. It also has something called a hot non-start - this means - it will not start when the engine is hot. You have to wait 20 minutes for the car to cool before it can start. If there is no emergency lane when your car shuts down - you are in trouble and in a very dangerous situation,. I have been stuck numerous times in traffic and then the car unable to start. Also as a result of this hot non-start- you have to fuel your car with it running or you will have to sit and wait at the gas pump for 20 minutes before it can start. This has occurred before they replaced my engine from 2009 thru 2011 and now with a new engine from 2012 thru 2015 they also need to be investigated for fraud. I leased my car for 3 years. I then purchased it and financed it for 5 years in 2008. Mazda knew these engines were flawed - but they were still selling them to people when this engine issue has been around since 2005. The car is dangerous to drive. Also - the apex seals can blow when you are driving the which means the car will shut down in traffic as well. I am not alone - search Mazda Rx8 engine issues on google - everyone has the problem.