QuestionQUESTION: I am looking forward to buying a rx-8 this year but do not know much about them. I am looking for the positives and negatives of this car and engine, mostly the engine I know that it consumes its oil as a secondary lubrication but other than that are there any other problems with the engine. Is it reliable,powerful,fuel economy,is it worth the buy.thanks
ANSWER: They are great well built machines. The rotary requires more TLC than an basic piston engine, coolant and oil changes using the proper oil and filter (Mazda) are musts. We change coolant twice a year and oil every 5,000. We also recommend a full synthetic oil. Since it burns it's own oil spark plugs (NGK) are an annual thing. Blast cleaning and reinstalling them are an option, but I normally recommend new ones every 24 months.
As for use, frequent start and stop, or short periods of running with out reaching full operating temperature should be avoided when possible. Apex seals (like the rings in a piston engine) can expand and contract, excessive fuel has an affect on them. These engines like to be run at RPM and do best when run for long periods.
A good option is to increase the engines CFM intake and output. The EPA regulates Mazda and so the intake and exhaust systems are fairly restrictive. A Racing Beat intake and exhaust system addition not only will improve power but also fuel efficiency.
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QUESTION: thanks, and how is the fuel economy is it really 18 to 22 mpg or less. Obviously its a sports car and who doesn't like to burn the fuel in a sports car but im just curious and can I still run 87 octane or do I need to run 93.How does it do in cold climate? I live in vermont where it gets very cold sometimes below zero, will it start ok in so cold of climate? Do you think this engine is really worth the buy, or is the wankel engine on its way out.
AnswerThe fuel economy is actual however, the heavier the foot the less the economy. It's certainly not a gas-mizer but it is fun to drive, hence the heavy foot. They run fine on 87 octane though I recommend in city to use mid grade and leave 87 for the long drives. Remember you burn oil as a normal use thing and higher octane fuels are more efficient during combustion. At your altitude you should be fine either way.
Rotary engines do fine in cold weather, they require a warm up period as do piston engines. Colder lighter air and cold fuel are like candy to a Wankel, you'll see a great improvement in power and economy in the colder months. In aircraft they make more power at altitude due to cold light air and better atomization of cold fuel.
The demise of the Rotary has been a long standing rumor for close to 20 years. It is still around and is better than it ever was in the RX8. The rotary is and will be for some time used in numerous applications. The US military uses them in RAPU remote auxilary power units in Alaska and world wide, these units are left in field running with weeks of constant use. Some small aircraft manufacturers use the Wankel to power there airplanes due to the power to weight ratios, less moving parts, high RPM ability and reduced rotational torque loads over a conventional piston/crank engine. The biggest negative of the Wankel was it was not fuel efficient, Mazda/Renesis 16x is the most simplified reliable and fuel efficient design ever created and it is standard equipment in the RX8.
