RX-8 vs. MX-5

[HL4EVR]

i want to know if rx 8 is good or the mx 05 miata is good
also want to know the procedure to import them into the country

[iceman91]

good in which way...what are you looking at in the car?

2 totally different type of engines and handling as well as performance...it goes on and on

MX-5 :2.0L DOHC MPFI 16-valve I4 engine w/variable valve timing

RX-8: RENESIS engine, 2,616 cc 2.6 liters rotary 2 front engine with 0 mm bore, 0 mm stroke, 10 compression ratio, none and zero valves per cylinder

Also the RX-8 has a rotary engine, much more of a sports car than the mx-5. Better performance and handling as well.

[Harbir]

Also the RX-8 has a rotary engine, much more of a sports car than the mx-5. Better performance and handling as well.

I have driven both and actually, that is not correct.

The NC (which is the 3rd generation MX-5) uses the same platform as the RX-8, with weighs much less and a much shorter wheelbase. This means that the NC has all of the wonderfulness of the RX-8, but at an even higher plane. Both are incredible good handling cars, with a very rare balance of responsiveness, agility, ease of driving hard, communicativeness. But the MX-5 is even better than the RX-8 on this front due to its shorter wheelbase and lower weight.

The RX-8 does not have the performance advantage either. In car and driver's testing, these are the numbers for the two cars:

0-60mph
RX-8: 6.5s
MX-5: 6.5s

5-60mph
RX-8: 7.5s
MX-5: 7.4s

1/4 mile
RX-8: 15sec/93mph
MX-5: 15sec/91mph

These are extremely similar numbers. But the MX-5 is actually a better performer because it weighs less and its engine is much more flexible and does not need extremely high revs to perform. this is seen in the top gear acceleration numbers. this is full throttle acceleration in top gear (6th) without chaning down:

30mph-50mph
RX-8: 12.1 seconds
MX-5: 8.7 seconds

50mph - 70mph
RX-8: 10.9 seconds
MX-5: 8.9 seconds

The problem for the RX-8 is that it weight 600lbs more than the MX-5, but its rotary engine does not have much power below 6000rpm. This means that if you spin the engine up and keep it above 6000rpm, it can about match the MX-5's performance (due to low weight). and if you are below 6000rpm, lack of power and excess weight leaves the RX-8 struggling against the MX-5.

the MX-5 is one of the lightest cars available today with this kind of performance potential.

The RX-8 is a better choice over the MX-5 if you need the rear rear and you favor a fixed roof.

but for India, I would advise the MX-5. Rotaries are not advised if your mechanic is not heavily experienced with them.

[Cyrus43]

If you are importing into the country, I suggest you take the Miati MX 5. The only reason is that it is Easier to Service and repair. The RX 8 is almost impossible to repair.

[Jayabusa]

Originally Posted by gta

If you are importing into the country, I suggest you take the Miati MX 5. The only reason is that it is Easier to Service and repair. The RX 8 is almost impossible to repair.

Could you please elaborate on the problems of the RX 8. :-)

[Harbir]

actually, if you have to open the engine up before 200,000km, that will be unusual.

but the RX-8 has problems of very heavy fuel AND oil consuption.

[flipsyde]

as much as i love everything about the RX-8 i wouldn't own one especially here in india because of poor service possibilities. and by the way the RX-8 is a 1300cc rotary engine.

rotary engines have almost no torque being produced at low rpms. which mean city driving is going to be terrible. but its rear wheel drive and that a lot of fun.

stick with the MX-5 ...... its the best value roadster money can buy today

[iceman91]

Originally Posted by Harbir

I have driven both and actually, that is not correct.

The NC (which is the 3rd generation MX-5) uses the same platform as the RX-8, with weighs much less and a much shorter wheelbase. This means that the NC has all of the wonderfulness of the RX-8, but at an even higher plane. Both are incredible good handling cars, with a very rare balance of responsiveness, agility, ease of driving hard, communicativeness. But the MX-5 is even better than the RX-8 on this front due to its shorter wheelbase and lower weight.

The RX-8 does not have the performance advantage either. In car and driver's testing, these are the numbers for the two cars:

0-60mph
RX-8: 6.5s
MX-5: 6.5s

5-60mph
RX-8: 7.5s
MX-5: 7.4s

1/4 mile
RX-8: 15sec/93mph
MX-5: 15sec/91mph

These are extremely similar numbers. But the MX-5 is actually a better performer because it weighs less and its engine is much more flexible and does not need extremely high revs to perform. this is seen in the top gear acceleration numbers. this is full throttle acceleration in top gear (6th) without chaning down:

30mph-50mph
RX-8: 12.1 seconds
MX-5: 8.7 seconds

50mph - 70mph
RX-8: 10.9 seconds
MX-5: 8.9 seconds

The problem for the RX-8 is that it weight 600lbs more than the MX-5, but its rotary engine does not have much power below 6000rpm. This means that if you spin the engine up and keep it above 6000rpm, it can about match the MX-5's performance (due to low weight). and if you are below 6000rpm, lack of power and excess weight leaves the RX-8 struggling against the MX-5.

the MX-5 is one of the lightest cars available today with this kind of performance potential.

The RX-8 is a better choice over the MX-5 if you need the rear rear and you favor a fixed roof.

but for India, I would advise the MX-5. Rotaries are not advised if your mechanic is not heavily experienced with them.

agree to all this..you are better informed than me!!!

but the rx-8 is much better in handling due to its engine positioning also if it starts at 6000rpm and stops at 8000..mazda has a car with a band of 2000rpm???

[iceman91]

These are the specs of an MX-%
Mazda MX-5 Specifications | Mazda Australia Zoom Zoom

these are the specs of an RX-8
Mazda RX-8 Specifications | Mazda Australia Zoom Zoom

there is a difference of 50kw of power and 32nm of torque!!!

the RX-8 hax max torqu at 5500rpm and MX-% at 5000rpm so if the rx-8 moves at 6000rpm.....???? what about the mx-5?

[Harbir]

1. The MX-5 and RX-8, use the same platform and thus have the same engine location in the chassis. While the RX-8 has the advantage of the rotary engine that lowers the car's CG compared to a piston engine, the MX-5 hits back with very little weight above the belt line (roof, heavy rear glass, window frames for 4 doors, etc) which brings the car's CG down, despite not having a rotary. Also, it having the engine mounted so far back like the RX-8, but also having a much shorter wheelbase (ie. having the rear wheels much closer to the engine than the RX-8) causes the MX-5's engine to be much more centrally placed than in the RX-8.

Believe me, as good as the RX-8 handles, the MX-5 is even better because it takes the RX-8 chassis, lightens, shortens and sharpens it. The RX-8 cannot match that.

In fact many of us Mazda fans are dreaming of an MX-5 with a fixed roof, fitted with the RX-8 engine, that could be called the RX-7, or perhaps keep the open roof and call it an RX-5.....

2. on your quotes of engine specs, the performance results are in front of you. the MX-5 equals the RX-8 on tests that involve a wheel spinning, high rpm clutch drop start from a stand still, and it beats the RX-8 in tests that involve just getting on the throttle without wheel spin.

Despite the RX-8's peak HP and torque advantage, the MX-5 matches or beats it because its much lighter and has a more flexible engine. the MX-5 is fully 600lbs lighter than the RX-8. that is the weight of 4 passengers!

The RX-8 starts to show its power advantage at high speed. Its 0-100mph is 18 seconds, vs 18.7 seconds for the MX-5. Its not a substantial difference, but its there. this is because at high speed, power to drag ratio becomes very important, vs power to weight ratio, and low weight does not help to offset lack of power. You need hp to overcome drag at high speeds.

As for the narrow powerband, thats not unusual at all. Honda's 2.2L S2000's power band runs from 6000 to 8000rpm. The same is the case for the Civic with the 197hp vtec engine, it was also the case for the Integra Type R.

None of these cars are famed for their out and out speed because they don't have it. their engines don't have the broad based flexibility, even while they have excellent handling, etc.

Like I said, the RX-8 is for people who like its looks, need the extra seats, want a fixed hard roof. otherwise, the MX-5 is the choice.

[iceman91]

Well i wont argue with that...
personally I still prefer the rx-8..driven both and the feel of an rx-8 is something else..

[HL4EVR]

and what is the procedure to import a MX 05 and who are the dealers

[Mpower]

Both are great cars. Unfortunately the Miata has an image of a chick car that keeps away the macho crowd.

The RX-8 in some ways is perfect for India because of the low labor costs. You will need an engine rebuild every 30K miles...sooner if you rip it. I cannot imagine paying for an engine rebuild here. Fuel economy is only 18 mpg and keeps getting worse. Beautiful car and one I would want to lease only.

[Harbir]

I think RX-8 owners will take very serious exception with this. The Renesis does not need a rebuild every 30,000 miles. Rotaries had an issue with worn out apex seals (seals at the apexes of the rotors that seal the three combustion chambers around each rotor from each other. Used to be RX-7s needed a rebuild every 90k to 120k miles. This was exacerbted in turbocharged versions because of the higher pressures inside the chambers.

The Renesis engine has high oil consumption because its apex seal lubrication design causes the engine to burn oil by design. But the result is that the Renesis does not have high wear issues like the older rotaries.

But it does have high fuel consumption and oil consumption issues.

As to the low labor cost issues, thats a bit of a red herring. I would never let anyone open up a rotary engine unless they had deep expereince with lots of them and I can't imagine that being easy to come by in India.

[Harbir]

As for the MX-5 being a chick car to the macho crowd, well the macho crowd must be populated by ignorant apes. The MX-5 is one of the best sports car ever made, and is far and away the most successful showroom based sports car in racing. here are some excerpts from Grassroots Motorsports, the bible of non-rpofessional racing in the US:

(full article at: Grassroots Motorsports » Articles & Interviews

Just about any “what car should I buy?” question on the Grassroots Motorsports online forum receives the same answer: the Mazda Miata. It’s the most popular car owned by GRM readers. We’ve had a bunch of them as project cars through the years, and currently have more than half a dozen in the fleet. So, what’s the fuss all about anyhow?

Well, it’s been credited with single-handedly saving the open-top sports car, paving the way for the Porsche Boxster, BMW Z3 and Honda S2000. It’s won countless autocrosses and road races, has a highly successful spec road racing series and has even been victorious at one of our Challenge events.

While many dismissed the cute little roadster as a girlie car (and many girls agreed that it did just fine that way, thank you very much) Miatas very quickly found their way to race tracks. That suspension turned out to work extremely well, and the car’s nimble handling and small size made it a giant-killer on a lot of tracks.

The first national victory came in 1992 when a Miata won the Showroom Stock C title at the Runoffs. It won again in 1993. And in 1994. The Miata didn’t win the SSC title in 1995 because it had been reclassed to Showroom Stock B–so it won that category instead. The Miata caught its breath in 1996 with a second-place finish, and resumed its Showroom Stock streak until being unseated in 2004. That’s 11 championships in 12 years.

Autocrossing wasn’t much different, with the Miata proving to be tough competition in a variety of classes. From 1993 to 1997, the car claimed 12 class titles at the Solo II Nationals.

On Track Today
Where can you road race a Miata? The most obvious answer is Spec Miata. This hugely popular series has driven up the price of ratty Miatas as hundreds have been converted to racers. While the upper echelons of the series are expensive to beat, it’s still possible to have some very close racing on a relatively tight budget–and even in a road-legal car. NASA, the SCCA and many regional clubs welcome the class.

Many Spec Miatas also take part in endurance events like NASA’s 25 Hours of Thunderhill, where the tough nature of the little car means the 25th hour can look like a Miata parade.

Other Miata-friendly road race classes are SCCA’s E and F Production. The 2004-’05 Mazdaspeed is classed in Touring 3 for the SCCA and looks to have a good chance in that class.

The Miata is still a very competitive autocross machine as well. The new STS2 class is designed to make the 1.6 cars run well against newer competition, while the NB cars are still a force to be reckoned with in C Stock as well as C Street Prepared; they took the top spots at the Nationals again last year. Even Street Modified 2 sees Miatas on the podium at the Nationals, although the Corvettes are tough to catch.

The pits at just about any track day also have a high percentage of Miatas. They’re forgiving enough to be good beginner cars, but still rewarding for an expert. A Miata on race rubber can surprise a lot of expensive machinery.