Considering Buying An Rx-8 But Im A Total Noob
03-11-2012, 06:05 AM
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Considering Buying An Rx-8 But Im A Total Noob
This is my first post so sorry if it is in the wrong place.
Basically im thinking about buying an RX-8. Im in the UK and the cars seem very cheap, around £4500 would buy you a 2005 with less than 25k on the clock.
From the reading I have done I would like to compression test the engine of any car I look at buying, is this a simple test like on a piston engine? Also with a low milage engine 25k or so what damage could have been done to the engine through either cheap or poor maintenance.
I have noticed some people mention pre mixing on the forums aswell is this still required to prolong the life of a modern rotary engine?
Thanks
p.s. if this is in the wrong place or is a repeat of a a previous post (I did try searching) give me a PM and I will contact a mod to have it moved or removed.
Basically im thinking about buying an RX-8. Im in the UK and the cars seem very cheap, around £4500 would buy you a 2005 with less than 25k on the clock.
From the reading I have done I would like to compression test the engine of any car I look at buying, is this a simple test like on a piston engine? Also with a low milage engine 25k or so what damage could have been done to the engine through either cheap or poor maintenance.
I have noticed some people mention pre mixing on the forums aswell is this still required to prolong the life of a modern rotary engine?
Thanks
p.s. if this is in the wrong place or is a repeat of a a previous post (I did try searching) give me a PM and I will contact a mod to have it moved or removed.
03-12-2012, 07:03 PM
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Thanks for directing me to that first thread as I read further into it I found more information. Reading though these forums I see a few problems threads but I can't work out a failure rate of these engines. If you buy a reasonable car with a good engine, is it any more likely to fail than a piston engine with proper maintenance? Im looking for a non biased answer for that because the rotary seems to have a love or hate following and I havent managed to work out how failure prone these engine actually are when looked after properly.
Im hoping to get my self a few rides in a few rx-8s to see how they feel before I look to buy one.
Im hoping to get my self a few rides in a few rx-8s to see how they feel before I look to buy one.
03-12-2012, 07:19 PM
#5
There is no definite answer to that question.
There are members on these forums who have made it well over the 200k mile mark ON THEIR ORIGINAL ENGINE.
However, there are members who have had 2 or more engines with less than 100k miles.
Make sure you know the full maintenance history of your car, before you buy.
There are members on these forums who have made it well over the 200k mile mark ON THEIR ORIGINAL ENGINE.
However, there are members who have had 2 or more engines with less than 100k miles.
Make sure you know the full maintenance history of your car, before you buy.
03-12-2012, 07:28 PM
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When you say check the maintenance history, would a mazda dealership service history be a good standard or is additional maintenance required for these engines, even at low mileages? Also how definitive is a compression test? Can an engine with good compression still be a wreck?
03-12-2012, 07:32 PM
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The Renesis is far more likely to last longer than a 1.3L 4 cylinder piston engine that is cranking out ~232hp.
However, it is more likely to fail before a 6 cyl piston engine putting out 232hp.
There are no hard facts and numbers. None. The results are all over the place.
The problem is that there are so many different ways for an engine to fail:
- Excessive carbon buildup accelerates seal wear, causing compression loss
- Excessive carbon buildup unseats the apex seals, causing compression loss
- Excessive heat buildup warps the housings to one degree or another, preventing the apex seals from sealing, causing compression loss
- Excessive exhaust temperatures overheat the side seal springs, warping them until the side seal pops out of it's location, clips the exhaust port and shatters, throwing shrapnel through the engine (usually race motors, possible but rare in street motors)
- Fuel pump failure or high lateral G left turns with low fuel causes fuel starvation under load, creating a lean spike that causes detonation and shatters seals
- Cat failure (even more common than engine failure) causes localized heat and pressure buildup that overstresses the seals and breaks down oil viscosity, leading to various issues
- Clogged oil injection lines prevent oil from being injected, leading to excessive apex seal wear and side seal overheating, leading to compression loss and/or catastrophic failure (depending on which fails first)
- Subpar reman engine quality, starting with low compression that accelerates any other issue
These are just the common failure methods. There are uncommon ones, and/or freak ones, like a transmission issue snapped one guy's e-shaft somehow (probably a defective e-shaft that was too weak), or issues that are entirely owner caused, like too low octane or not keeping on top of the oil level.
Any single preventative measure you can find only addresses at best a couple of these, maybe just one method, and maybe none at all (but people think it does). And since you don't usually know how well the engine was put together in the first place, it's largely a roll of the dice on these engines.
Short answer though: If it makes you that uncomfortable and/or paranoid, then this is not the car for you. You have to accept the issues or ownership will turn into a nightmare. It still could anyway, but your mindset going in is far more important than statistics. The more prepared you are, financially and mentally, the less of a problem any of this will actually be for you.
However, it is more likely to fail before a 6 cyl piston engine putting out 232hp.
There are no hard facts and numbers. None. The results are all over the place.
The problem is that there are so many different ways for an engine to fail:
- Excessive carbon buildup accelerates seal wear, causing compression loss
- Excessive carbon buildup unseats the apex seals, causing compression loss
- Excessive heat buildup warps the housings to one degree or another, preventing the apex seals from sealing, causing compression loss
- Excessive exhaust temperatures overheat the side seal springs, warping them until the side seal pops out of it's location, clips the exhaust port and shatters, throwing shrapnel through the engine (usually race motors, possible but rare in street motors)
- Fuel pump failure or high lateral G left turns with low fuel causes fuel starvation under load, creating a lean spike that causes detonation and shatters seals
- Cat failure (even more common than engine failure) causes localized heat and pressure buildup that overstresses the seals and breaks down oil viscosity, leading to various issues
- Clogged oil injection lines prevent oil from being injected, leading to excessive apex seal wear and side seal overheating, leading to compression loss and/or catastrophic failure (depending on which fails first)
- Subpar reman engine quality, starting with low compression that accelerates any other issue
These are just the common failure methods. There are uncommon ones, and/or freak ones, like a transmission issue snapped one guy's e-shaft somehow (probably a defective e-shaft that was too weak), or issues that are entirely owner caused, like too low octane or not keeping on top of the oil level.
Any single preventative measure you can find only addresses at best a couple of these, maybe just one method, and maybe none at all (but people think it does). And since you don't usually know how well the engine was put together in the first place, it's largely a roll of the dice on these engines.
Short answer though: If it makes you that uncomfortable and/or paranoid, then this is not the car for you. You have to accept the issues or ownership will turn into a nightmare. It still could anyway, but your mindset going in is far more important than statistics. The more prepared you are, financially and mentally, the less of a problem any of this will actually be for you.
03-12-2012, 07:36 PM
#8
If the car was serviced at mazda, then yes, that should be a good standard (even though mazda techs can often times mess up!).
An engine with good compression will last, as long as you pay attention to the maintenance schedule. Try to learn to do your won work, as you'll save yourself a ton of money, as well as learn more about the rotary.
Most of the questions you have are answered in either the thread I linked to you in the first response, or else in other stickies. Read and re-read at least the first few pages of each sticky that is relevant to you.
An engine with good compression will last, as long as you pay attention to the maintenance schedule. Try to learn to do your won work, as you'll save yourself a ton of money, as well as learn more about the rotary.
Most of the questions you have are answered in either the thread I linked to you in the first response, or else in other stickies. Read and re-read at least the first few pages of each sticky that is relevant to you.
03-12-2012, 07:41 PM
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Perfectly good compression means a perfectly good engine. End of story. It's the only engine data point that really matters. Anything that might make it "not that good of an engine" will affect compression negatively.
Other supporting components can be complete trash and destroyed though. Ignition, steering rack, steering connectors, clutch, transmission gears and syncros, alternator, fuel injectors, intake valving, OMP, oil lines, water lines, water pump, grounding points, relays, fuses, etc... None of them impact the engine's compression directly, but could cause an engine to run poorly or not at all. The starter is the only other component that could impact engine compression test results, because the starter is used to spin the engine for the test, and a lower spin means lower compression. There is a correction chart for starter speeds other than 250rpm.
03-12-2012, 07:50 PM
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Thanks for the replys. I work as a mechanic (not cars but I have rebuilt a few piston engines and worked on quite a few cars in the past) so maintaining the car once I have it is not an issue. I dont intend on hammering the car but I would like it to last 2 years of fun driving and be in a sellable condtion afterwards. (I estimate taking the car from around 30k miles to around 55k miles). They are lovely cars, I just want to make 100% sure I can commit to an RX-8 before I get too exited about it!
03-12-2012, 08:32 PM
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If you get even a marginally acceptable compression test results, it will last 15,000 miles. That isn't even really a worry. Barring any overheating or owner stupidity.
And hammering on this engine is healthy for it. Lugging it around will kill it due to the carbon buildup mentioned. Going around at high RPM constantly is what will overheat the side seal springs though. A balance. Not a steady state balance, but a balance of what type of driving you do.
And hammering on this engine is healthy for it. Lugging it around will kill it due to the carbon buildup mentioned. Going around at high RPM constantly is what will overheat the side seal springs though. A balance. Not a steady state balance, but a balance of what type of driving you do.
03-13-2012, 02:05 PM
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My drive to work is half 40 limits and half national limit (uk 60mph single lane road) which would mean good opportunity to spin the engine up every journey pretty much. Im just trying to work out the cost of running this car for the 2 years I want to keep the car compared to other option I have in mind. Am i allowed to ask about other cars (in comparison to the rx-8) in here or is that aginst the rules?
Last edited by Bauwz; 03-13-2012 at 02:11 PM.
03-13-2012, 03:17 PM
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Sure, you can ask. But our opinion is going to be decidedly biased 
You can generally expect that most of the answers you get are not going to approach the issue from a comprehensive and complete perspective.
And it really gets down to why we love this car. It's an emotion to us. Inherently not logical or reasonable. The people that dislike the 8 do so passionately as well. Everyone likes to come up with logical reasons to like or dislike it, but in the end it's all about how the car you drive makes you feel. If the only way it impacts you is not feeling wallet-raped every month, then you are going to bias toward cost efficient cars.
For most of us, the only feeling we pursue is that what plasters that grin to our face. And everyone gets it differently. For some ex-owners that hate it, the feeling is one of devastation, anger, or even betrayal. Largely, those owners bought it and either tried to make it something it's not, or bought it without any idea of what they were getting into.
Definitely rule out any vehicles that don't make sense financially. But if it's between two or more cars that are all reasonably affordable to you, you will end up picking the one that makes you feel the best. Or gives you the feelings you are seeking most accurately.
With only expecting to keep it 15,000 miles, there is little you can say against the 8's reliability, assuming it's in good shape to begin with. Whether or not you can bear to part with it after those 15,000 miles is going to be up to you. If you can't, then the reliability might become more of an issue, but you will also have more emotional reason to ignore that cost factor
For me, I've been contemplating moving on from the 8. But I know I will always regret selling it. Will I be able to live with that regret? Will my next car be sufficient to fill that gap? That's my concern point. It has nothing to do with the financials. Only whether or not I will be able to fill the hole it will leave in my heart.
To anyone that asks, I always tell them: Find a car that speaks to you. Find one you enjoy. One that puts a smile on your face. There is nothing else like it. It doesn't have to be a rotary, good handling, or even pretty. If it fits you, then it's a perfect fit. Enjoy!
You can generally expect that most of the answers you get are not going to approach the issue from a comprehensive and complete perspective.
And it really gets down to why we love this car. It's an emotion to us. Inherently not logical or reasonable. The people that dislike the 8 do so passionately as well. Everyone likes to come up with logical reasons to like or dislike it, but in the end it's all about how the car you drive makes you feel. If the only way it impacts you is not feeling wallet-raped every month, then you are going to bias toward cost efficient cars.
For most of us, the only feeling we pursue is that what plasters that grin to our face. And everyone gets it differently. For some ex-owners that hate it, the feeling is one of devastation, anger, or even betrayal. Largely, those owners bought it and either tried to make it something it's not, or bought it without any idea of what they were getting into.
Definitely rule out any vehicles that don't make sense financially. But if it's between two or more cars that are all reasonably affordable to you, you will end up picking the one that makes you feel the best. Or gives you the feelings you are seeking most accurately.
With only expecting to keep it 15,000 miles, there is little you can say against the 8's reliability, assuming it's in good shape to begin with. Whether or not you can bear to part with it after those 15,000 miles is going to be up to you. If you can't, then the reliability might become more of an issue, but you will also have more emotional reason to ignore that cost factor
For me, I've been contemplating moving on from the 8. But I know I will always regret selling it. Will I be able to live with that regret? Will my next car be sufficient to fill that gap? That's my concern point. It has nothing to do with the financials. Only whether or not I will be able to fill the hole it will leave in my heart.
To anyone that asks, I always tell them: Find a car that speaks to you. Find one you enjoy. One that puts a smile on your face. There is nothing else like it. It doesn't have to be a rotary, good handling, or even pretty. If it fits you, then it's a perfect fit. Enjoy!
Last edited by RIWWP; 03-13-2012 at 03:26 PM.
03-13-2012, 06:02 PM
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Basically its a choice between an rx-8 and an mx-5. This is my first RWD car, I feel I need to progress from FWD! I've decided between those 2 because they are nice cars with good reviews from drivers and the insurance is reasonable (insurance is a huge issue for younger drivers in the uk) The mx-5 is cheaper to run but a 1.8 Sport mx-5 costs the same to buy as a similar age rx-8 (231) and I feel you get more car for your money with the rx-8. I have never driven either car and I need to get out on a few test drives but because my current car is a POS and im fairly young I dont think dealers would be too keen on letting me test drive cars, particually as my insurance only covers me to drive my car untill im 25.
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
03-13-2012, 06:32 PM
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Basically its a choice between an rx-8 and an mx-5. This is my first RWD car, I feel I need to progress from FWD! I've decided between those 2 because they are nice cars with good reviews from drivers and the insurance is reasonable (insurance is a huge issue for younger drivers in the uk) The mx-5 is cheaper to run but a 1.8 Sport mx-5 costs the same to buy as a similar age rx-8 (231) and I feel you get more car for your money with the rx-8. I have never driven either car and I need to get out on a few test drives but because my current car is a POS and im fairly young I dont think dealers would be too keen on letting me test drive cars, particually as my insurance only covers me to drive my car untill im 25.
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
FWD cars aren't so bad but a RWD car is definitely the way to go. I've owned a few and currently have a 2002 V6 Accord as a daily driver.
I'd get an NA Miata all over again! ....but I got an eight instead since the budget allows me to own a second car, and a princess of a second car this girl will be.
Last edited by SubliminalPollution; 03-13-2012 at 06:35 PM.
03-13-2012, 07:51 PM
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Well, of all cars out there, you will find more objective responses for a Miata comparision. Quite a few of us own both.
What series MX-5? Based on price, I'm guessing a 2006-2008 NC. I think there was a 1.8L NC in Europe. Otherwise, NB. I currently own a 99 NB Miata, soon will be swapping to a new 2012 NC.
Comparison to an NC:
The RX-8 and the NC share much of the same chassis design. Suspension geometry is very close, drivetrain aft of the engine is almost identical (same transmission, diff housing). They feel very similar. The openness of the NC and they unavoidably less smooth engine give a more raw experience, vs the closed coupe of the 8 and the much smoother engine. The longer wheelbase of the 8 is more stable at high speed, cornering or straights. More confidence building that the more unstable shorter wheelbase of the NC. Not a direct issue, but the wheel base of each does play a role in what speeds each car is more comfortable at. An NC feels better at low speeds that the 8, the 8 feels better at high speeds. This can lead to legal issues
The 8 has been very accurately described as the more refined brother/sister to the NC. In costs and engines they are radically different. The NC being cheap to own and the RX-8 not. Power to weight ratio is very similar, so acceleration feels similar, with the Miata better off the line, but more strained at highway speed.
Comparision to the NB:
Basically everything for the NC, except in a farther scale from the 8. It's lighter, better at low speeds, even more strained at high speeds, more unstable chassis, even cheaper to own, more raw in engine and open air. Less refined than the NC. Still a blast, but in a more different way than the NC vs 8.
What series MX-5? Based on price, I'm guessing a 2006-2008 NC. I think there was a 1.8L NC in Europe. Otherwise, NB. I currently own a 99 NB Miata, soon will be swapping to a new 2012 NC.
Comparison to an NC:
The RX-8 and the NC share much of the same chassis design. Suspension geometry is very close, drivetrain aft of the engine is almost identical (same transmission, diff housing). They feel very similar. The openness of the NC and they unavoidably less smooth engine give a more raw experience, vs the closed coupe of the 8 and the much smoother engine. The longer wheelbase of the 8 is more stable at high speed, cornering or straights. More confidence building that the more unstable shorter wheelbase of the NC. Not a direct issue, but the wheel base of each does play a role in what speeds each car is more comfortable at. An NC feels better at low speeds that the 8, the 8 feels better at high speeds. This can lead to legal issues
The 8 has been very accurately described as the more refined brother/sister to the NC. In costs and engines they are radically different. The NC being cheap to own and the RX-8 not. Power to weight ratio is very similar, so acceleration feels similar, with the Miata better off the line, but more strained at highway speed.
Comparision to the NB:
Basically everything for the NC, except in a farther scale from the 8. It's lighter, better at low speeds, even more strained at high speeds, more unstable chassis, even cheaper to own, more raw in engine and open air. Less refined than the NC. Still a blast, but in a more different way than the NC vs 8.
03-13-2012, 08:05 PM
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The mx-5 would be a 1.8 sport 2003 or 2004 mk 2.5 with 50k on the clock. The 8 would be a 2005 231 engine with 30k on the clock. Both priced around £4500.
The rx-8 is so cheap due to petrol costing £1.40 a litre. £4500 is about the price I want to spend so I cannot afford the mk3 miatas. I have noticed that miatas do rust and it has been mentioned the rx-8s have corrosion problems aswell however I assume with it being a newer model the 8 would be the better of the 2 as far as rust is concerned.
The rx-8 is so cheap due to petrol costing £1.40 a litre. £4500 is about the price I want to spend so I cannot afford the mk3 miatas. I have noticed that miatas do rust and it has been mentioned the rx-8s have corrosion problems aswell however I assume with it being a newer model the 8 would be the better of the 2 as far as rust is concerned.
03-13-2012, 08:14 PM
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WTB,
He is asking clear and precise questions that are building on prior answers, not being disrespectful or appearing to asking for spoon feeding. I wish every newbie approached car buying this way.
Leave him alone
He is asking clear and precise questions that are building on prior answers, not being disrespectful or appearing to asking for spoon feeding. I wish every newbie approached car buying this way.
Leave him alone
03-15-2012, 01:25 AM
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Basically its a choice between an rx-8 and an mx-5. This is my first RWD car, I feel I need to progress from FWD! I've decided between those 2 because they are nice cars with good reviews from drivers and the insurance is reasonable (insurance is a huge issue for younger drivers in the uk) The mx-5 is cheaper to run but a 1.8 Sport mx-5 costs the same to buy as a similar age rx-8 (231) and I feel you get more car for your money with the rx-8. I have never driven either car and I need to get out on a few test drives but because my current car is a POS and im fairly young I dont think dealers would be too keen on letting me test drive cars, particually as my insurance only covers me to drive my car untill im 25.
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
If anyone has owned an mx-5 any info on what they thought of it and why they own an rx-8 and not an mx-5 still would be great!!
I traded in the RX-8 in December 2011.
My unvarnished opinion:
The rotary has definite advantage for a sporty car in terms of handling, and the RX-8 makes good use of this. The handling is fantastic and you can push it past reasonable limits and it keeps its poise.
Fuel economy sucks. And that is at USA prices. I can't imagine driving an RX-8 as a commuter in the UK unless yours is a very short commute.
The engine is fussy. That's great if you like tinkering. Or if you just like having a unique engine. I did like that aspect. General consensus is that pre-mixing oil into the gasoline (tinkering) helps with longevity. That's important because, best I can tell the Renesis can probably be relied upon to give about half the service life of a contemporary piston engine.
The transmission has been noted as a weak point.
These are reasons why you are seeing such a good deal in price.
After my 8 years with the car I will say, it was great fun and if you value handling above all else, get the RX-8 and have a blast. If you definitely need 4 seats, get the RX-8 and have a blast.
Otherwise, I think the Miata was the better car. The handling was also fantastic and the lighter weight makes up for the polar-moment advantage of the RX-8 in terms of "tossability". For just enjoying the road, as opposed to raw limits, The Miata wins. The Miata was bullet-proof in reliability over the 14 years and 150+thousand miles I drove it. The mechanicals were straightforward and there was no fuss. Decent fuel economy. And never underestimate the joy of a convertible, especially in such a nimble car. If you want to just have fun with minimum fuss, get the Miata and have a blast. If you don't want to spend a fortune in gasoline, get the Miata and have a blast.
I loved the Miata and still miss it. That great experience led me to the RX-8 in a search for the Miata's "big brother". Which it was, in some measure. The RX-8 was fun but I find that I don't have quite the longing as with the Miata.
