My Mazda mechanic told me an RX-8 engine will usually die with only 30 to 90K miles on it, and cost over $5000 to fix. How long do '93 RX-3 engines last??

 

Bulllsiiiiiit lol. Everything I've seen shows miles far exceeding that!

 

I'm assuming you mean rx7 and not rx3... 200k miles isn't unheard of but depends how the vehicle was maintained and treated during its life.

 

would you jump off a bridge if I asked you to??

Don't listen to People that do not have a Clue about the Rotary Engine Platform.
At least you are HERE and can get the REAL truth!

 

I sold my rx8 with 125k miles original engine and had above 90 all faces compresion, take a good care of the car and you will have a good experience and happy engine.

 

93 octane gas always no cheap atuff, coils coils coils always have good coils. Always have good spark plugs ngk keep you oil changed. Dont cheap out and do at least one full throttle acceleration a month to keep the carbon from screwing the engine. Do this and she will last easily over 100k miles. Cheap out and dont take care of maintenance and it could be a very different story. Dude rotary engines are not bad but some owners dont take care of them and that ia what givea rotary engines a bad rep. Brap on brother and enjoy. Also do good research before you just start modding

 

Force induction creates heat. Heat creates stress. Stress shortens the life-span of engine components. All 3rd Gen (FD) RX7's were turbocharged. In a relatively stock FD with good maintenance, adult driven and never overheated I think the usual culprit is a soft seal (coolant seal) failure around 100K.
That's the rough equivalent to a head gasket on a piston engine, the biggest difference is that it requires complete disassembly of the engine to replace. So while you're in there it makes sense to replace other wear parts...hard seals, hard seal springs, bearings etc. The good news is that even with the rise in cost of wear parts like housings, the engine isn't any more expensive and usually less than an equivalent piston engine. And internally simpler.

 

/\...or Drive it like you Stole it!!

 

I disagree. The rotary isn't a tractor engine and doesn't like to be lugged. But IMO just ragging on it accomplishes little other than accelerated wear. If carbon is a concern change oil more frequently, avoid short trips as best you can, keep a good tune, keep an eye on your plugs, fuel filter and maybe regular fuel system cleaner. If it's forced induction, consider AI/WI.

 

I agree id it is a 3rd gen engine all of the above is true. I am an adult but i do believe in getting on it once a month. I am not talking about abusingg it. You know the old 4000 rpm and dropping the clutch or taken it ro 8 or 9000 rpm. Juat give a good pull every once in a while. She was ment to be driven but not abused

 

The originally-specified oil for the RX-8 was too thin. This was a problem with bureaucracy, not with the engine.
Mazda RX 8's Engine Failure Problem - Mazda Discussions at Automotive.com

If you are concerned about the RX-8 engine, then don't swap one into your 93 RX-7, which has a completely different engine.

The octane rating is not necessarily related to the quality of the fuel. This is because higher octane ratings are achieved with cheap stuff (alcohol), or good stuff (aromatics), and good luck getting the gas station to tell you what is actually is in their high-octane fuel. Additionally, the octane rating is based on the fuel's anti-knock performance in NA engines, so that may or may not translate to turbocharged engines. Unfortunately, the dubious octane rating posted on the fuel pump is typically the only fuel information that we get as consumers, so I guess it is better than nothing.

As for quality, I recommend sticking to fuels that at least have a nice set of detergent additives that will help keep your engine and fuel system clean. Fortunately, there is a 'top tier' standard for this.
Licensed Brands | Top Tier Gas

Modern engine oil is fantastic at keeping carbon in suspension, so the normal changing interval is fine. Castrol GTX oil is really good at keeping the engine clean, I have no idea why, but all of my friends notice this when rebuilding their rotary engines and 4-cylinder engines. The biggest factors are the good tune and avoiding short trips that you mentioned. Also, water injection (with added water-soluble oil) does a great job at cleaning, although the system is a pain in the butt to maintain.

^ This. The main concern is that the engine rpm needs to be high enough for the secondary fuel injectors to operate. If you short-shift and drive around at low RPMs like a grandma thinking that you are 'babying your engine', the secondaries will clog up due to disuse, and when you do finally need to accelerate quickly the engine will blow.

 

I've had WI on my car for...not sure, maybe 9 years. VERY simple boost activated system. In that time I've had to replace a $25 Hobbs/pressure switch. Controls carbon AND knock AND additional cooling.

 

60-70k seems to be typical engine life for cars with light mods. Usually less when people go extreme