The Mazda RX 8 Horsepower: The Best Worst Cars

I love my Mazda RX 8 horsepower. It’s a car that I truly love driving and working on like nothing else that I have owned. But I am also well aware that this car has its issues and is not for everyone. I hope that if someone is considering buying and owning one they read this and take away something useful to help guide their choice.

The first time I sat in a Mazda RX-8 was back at the 2005 Detroit-North American International Auto Show. I remember getting myself into that tiny sports-car and feeling like the car was designed for me. The seats hugged me just right, and my arms and legs reached the pedals and steering wheel so naturally. Did my passion for everything rotary skew my emotions on that fateful day? Probably. But from that moment on, I knew at some point in time, I was going to own an RX-8.

I spent many years looking at, and considering Mazda RX 8 horsepower, but I always ended up talking myself out of it a buying something more practical. Then in September of 2011 soon after I sold my Fiero, I finally fulfilled my dream of owning my own RX-8.

My RX-8 provides me with a zen-like driving experience. I love nearly everything about it. Its steering provides the best feedback I’ve ever had. Its handling makes the car feel like it rotates right around where you are sitting and the level of grip is remarkable. It’s a car that gives an inexperienced HPDE/Auto-X driver (What I consider myself) an extremely high level of confidence to push the car right up to its limit. Oh, and there is that special feeling of winding out the rotary engine up over 9500 RPM’s. I love the scream of rotaries. While not overpowering, the 240hp and the gearing of the transmission makes you feel like you are driving faster than what you really are.

While the incredible driving experience is my favorite thing about the RX-8, it is also one of the more practical sports-cars out there. While many have issues with its odd-shape and suicide rear-doors, these two things become amazing when you have kids. I have two children (3 and 5) and they both fit great in their car-seats in the back and the suicide doors make getting them in and out a breeze. And for such a tiny car, the interior room is excellent. I’m 6’3″ and fit nicely while my kids still have room behind me. There are many other cars out there that I can’t say the same for.

The RX-8 is also one of the easier cars I have worked on. Although the engine bay is cladded with lots of plastic covers, any job I have done under the hood had been a rather disaster-free experience. Brake and suspension work has been the same. In certain spots it seemed like the engineers took the time to make sure that one could actually get ratchets and sockets onto bolts. There have been many other cars I have worked on that I certainly cannot say the same for.

In the 4+ years I have owned my RX-8, I have talked about my love for it and of rotaries in general with the fervor of a crossfitter or a vegan. I own pretty much every rotary t-shirt Blipshift has ever made. I have all kinds of rotary memorabilia. So it might come as a surprise when someone I know comes up to me and say to me “Hey, I’m thinking of buying an RX-8.” My response is an emphatic:

Don’t! Now why on earth would I try to talk someone out of a car that I have just been gushing over like it’s the greatest thing ever? That’s because in the hands of most people, even a fair bit of skilled auto-enthusiasts, an RX-8 is like a metal-dorito-whirling-time-bomb just waiting to blow up someone’s wallet, time, and general love of automobiles.

RX-8’s have a laundry list of things that fail on them:

  • The engine itself failed so often that Mazda extended the powertrain warranty to 8 10-years/100k miles and they built a facility here in America to handle all of the rebuilds. (This was a result of a number of things, but it was mainly a result of Mazda trying to lower engine-oil consumption to a point where someone would not have to add oil between service intervals.)
  • Coil-packs last ~30k miles if you’re lucky.
  • The enormous catalytic converter fails due to the failing coilpacks not providing a proper combustion and plugging the cat with unburned crap. This also increases the potential for destroying the engine.
  • The original power steering harness was assembled with paperclips and bubble gum. You will then need to start building up you biceps to get the car to steer.
  • If you shut off the car too quickly after you started it without revving it while you shut it off, you can flood the engine with fuel. The terrible coil packs once again won’t give you enough spark to get it to fire. You will need a tow to the dealer to de-flood it, lightening your wallet by a couple hundred bucks.
  • Carbon build-up from not revving your engine can result in scoring your rotor housings and seals so bad that you will lose compression. Buildup will also stop the various intake valves from working properly robbing you of any power you might have a hope of making.
  • The starter is weak.
  • They have the awesome metal-shooting Takata airbags.
  • S1 transmissions like to grenade 4th gear after excessive abuse. S2 transmissions are a direct swap except for changing on electrical connector and it’s the tranny found in the Miata.
  • The stock clutch pedal mount likes to bend over time and will potentially stop you from disengaging the clutch.

I’m sure there are other common failures I can think of but that’s a good enough list to make nearly anyone steer clear of RX-8 ownership. But if you are still reading this and thinking “Well, I am a bit of a masochist, maybe an RX-8 would be cool to have”, I do have some advice for you in selecting a decent RX-8 as well as ensuring having a trouble-free ownership experience with it.

My first bit of advice is the easiest and really makes all of my other advice pointless as it is all covered in far better detail.

Buying a Mazda RX 8 Horsepower

If you have the money, I definitely suggest buying an S2 RX8. The 2008 2009-2011 S2 RX-8’s have far less issues and Mazda corrected many, if not all, of the issues that the 2004-2007 S1 RX8’s had. If you are on a budget and can only afford an S1 RX-8, try to stay away from ‘04’s as they had most of the engine issues.

I would look for a car that has already had its engine replaced and has plenty of service records. A car with 75k miles with service records and an engine with less than 5k miles on it is a safer buy to me than one with 30k miles and no records. There are plenty of RX-8’s for sale that meet this criteria and many can be found for under $7500.

When you actually start looking at RX-8’s, make sure you are able to start the car up cold. If you have excessive cranking, it could mean that the coilpacks/plugs are failing. Then after driving it and the car has warmed up, turn the car off, and wait a few minutes. If the car is cranking excessively without turning over, chances are that the engine is on its way out with low-compression. Both warm and cold starts can tell you a lot about the health of the car.

If possible, ask the seller if they have had a compression test done. If you are really interested in the car, maybe even offer to split the cost of the test for the peace of mind. You don’t want to buy a car with the engine on its way out unless it’s still within the 10 8yr/100k warranty period. Note: Rotary compression-tests are not done like a standard engine. You need to have a special machine and more than likely have to have it done at a Mazda dealer.

When driving the car, make sure you are able to wind it up to redline after it had warmed up. If if feels like it’s falling flat on its face above 7k RPMs, it might be another sign of a weak ignition or it could be a sign that the SSV’s (Sequential Shutter Valves) are not opening properly (probably due to buildup or lack of use.)

If you are buying private party, get a feel for the seller. Hopefully he’ll be explaining things about the car the way I am here. If he or she seems like the ‘puts gas in it and drives’ type, I would be a bit weary of buying a car from that type. This is really a car the needs to be enthusiast-owned.

If buying from a dealership, see if you can have a pre-purchase inspection done by a rotary-specialist independent shop or a knowledgeable Mazda dealer. Believe it or not, some Mazda dealers have no techs that have any reasonable rotary knowledge.

I looked at and test drove over 10 RX-8’s before I found what I wanted. I bought my RX-8 with 73k miles on it. It was a 1-owner car with a stack of service records, and most importantly to me, a replacement engine less than a 1000 miles ago. The seller did seem to know a fair bit about the car and she kept up very good on maintenance and even carried oil in the trunk!
If I had the money, a 2009-2011 RX-8 R3 would be my ideal RX-8 to own.

Driving Mazda RX 8 Horsepower

This needs to be done often (Well maybe not at that speed. I might suggest a lower gear)
There’s a relatively common saying in the rotary-world. “A redline a day keeps the mechanic away”. This little bit of advice is crucial to owning a happy RX-8. There are many accounts of RX-8 owners doing a track-day who are amazed at how much better their car is running afterwards. This is because all the carbon deposits within the intake track tract and rotor housings got blown out. A clean engine is a happy one.

I redline my car virtually every trip I make in it and try to do a WOT 2nd, 3rd, 4th pull whenever possible. Besides it being good for the engine, I love the sound it makes and it makes me feel all giggly inside.

I also do my best to make sure the car warms-up completely. With the improvements I have made mentioned below, I really don’t have to do anything crazy to make sure my RX-8 will start up again. Even still, I do my very best to ensure that the car comes all the way up to temp. I do this even if I have to go out of my way a little bit.

Also make sure to run premium fuel. Detonation from low-octane gas could result it broken apex seals rather quickly. And by the way, RX-8’s get terrible gas mileage. 20MPG is a good tank.

Things to make a Mazda RX 8 Horsepower more reliable:

This might sound hard to believe after all the bad things I have mentioned, but I have driven my RX-8 for almost 27000 miles with only one issue; a bad power steering harness. The way I acheived this was by saving $1000 or so dollars beyond the purchase price of my car to buy a number of thigns that would help with many of the aforementioned issues.

Here are the things that I consider almost mandatory if you want a good-running RX-8. For many of these parts, there are a few different choices amongst different vendors. I am only listing the parts I have actually used:

Premix Oil.

I run about 6oz of Lucas Synthetic 2-stroke oil in every tank of gas. I have also run Idemitsu Rotary premix, but it’s expensive and I have to order it online. I keep it in pre-measured bottle in my trunk. Whether premix is needed is a long-debated topic, but I find it better to be safe than sorry. Plus, unlike conventional motor oil, it is designed to burn and lubricate in the combustion chamber.

SOHN Oil Metering Pump Adapter and Oil tank.

Like mentioned above, 2-stroke oil is designed to burn and lubricate. Conventional oil is not. The SOHN OMP adapter allows you to run a separate oil tank so that your oil-injection system can get fresh, clean 2-stroke oil as opposed to dirty, conventional crankcase oil. I originally adapted a generic coolant overflow tank to use as my oil tank, but the seller Epitroch on Ebay offers a nice adapter plate that replaces the washer reservoir and adds an oil-tank. Another added benefit is that you can now run quality synthetic oil in the crankcase.

Ignition Coil Upgrade

Black Halo Racing Coil-packs are one of the best mods you can make for your Mazda RX 8 horsepower. If you’re still reading this, you could probably figure out that many of the RX-8’s issues is due to a weak stock ignition system. Black Halo Racing makes an ignition system upgrade based off of GM LS-style coils. These provide a stronger, and far more reliable spark. Yeah, it’s expensive and I know there are competitors that offer a less-expensive version. No matter what upgrade you choose, it will be a huge upgrade over stock.

Catless midpipe.

If you live in an area that you don’t have to worry about emissions, I suggest dumping the enormous catalytic converter and replace it with a quality midpipe. Aftermarket companies also make better flowing catted-midpipes as well. An added bonus is that you’ll probably be able to shoot flames out of your exhaust now! If you can’t dump the cat, at least take the time to pull it off and inspect it to make sure it doesn’t show any kinds of clogging. The stock cat holds-in a lot of heat so you want to make sure it’s not already failing. Running premix probably adds stress to the cat as well, so you might want to consider how much, if any, premix you want to run.

Cobb ACCESSPORT or another tuning solution.

I have a COBB ACCESSPORT. I also used the tuning service in the beginning but ran out of time to get my tune finished. Fortunately I have a decent amount of experience in the tuning department and eventually created my own mild tune. Having a proper tune on your car can help you nab a bit of power and potentially gain some efficiency. An RX-8-specific benefit is being able to adjust OMP-flow rates.

Catch-Can.

If you look inside the flex hose before the throttle body, chances are you will find oil pooled inside it. Especially if the car has been over-filled with oil. As with most cars, all this oil and the accompanying vapors are not good for the intake track tract and combustion. A catch-can will help keep all that nasty stuff out of the engine.

Mazda RX 8 Horsepower – Conclusion

So while there are plenty of other things you can do to your RX-8, I consider the above mods and driving habits essential to ensuring a high level of reliability over a long period of time.

I hope this has helped people to understand the Mazda RX-8 a little bit better and if you are considering buying one, I hope this will help not only with choosing the right RX-8, but more importantly, that it will help you to have a good-running and fun car right from day-one.

I also hope that it will help people realize that maybe an RX-8 is not right for them. I’m sure many of us have cars we regret buying and I have read about more than a few nightmare stories with the Mazda RX 8 Horsepower that could have been avoided with some better knowledge.

Leave a Comment