Mazda RX8
Road test report - November 2007

by Kevin Fenix.

Mazda’s RX8 is unique amongst today’s prestige cars in that it is the only one powered by a rotary engine. The rotary engine was big news back in the early nineteen seventies, when several manufacturers had purchased the rights to develop and build them. Mazda was amongst those early enthusiasts for the concept and were undoubtedly the most successful. There were difficult engineering problems which Mazda alone managed to eliminate and solve. Then came the first fuel crisis and suddenly the rotary engine lost its attraction for all those interested parties, except Mazda. The reason we were told was because of the rotary engine’s higher fuel consumption. This begs the question, higher than what ? The biggest interest in the rotary engine was in North America, the same country where interest dropped off to nothing in the wake of the fuel crisis, yet the Yanks still went on producing five, six and seven litre V8s, which undoubtedly used more fuel than a 1.3 litre rotary.
To put this into perspective I referred to my archives and discovered some interesting information. In 1980 - after the second oil crisis - the Mazda RX7 had a twin rotor engine, with a total capacity of 1146 cc and giving 96 kW. It delivered a top speed of 112 mph and a fuel consumption of 25 mpg. By way of comparison the Chevrolet Camaro had a 3.7 litre V6 giving 81 kW, which delivered a top speed of 108 mph with a fuel consumption of 23 mpg. Ford’s emasculated Mustang with a 2.3 litre four cylinder produced 66 kW, which gave a top speed of 96 mph and 27 mpg. The 4.1 V8 version of the Mustang delivered 90 kW with a top speed of 100 mph and a fuel consumption of 21 mpg. So while the rotary may have used a lot of fuel for its capacity, it delivered a performance that was far better than engines four times its size ! If you compare performance delivered with fuel used, the Mazda rotary was certainly no worse than engines capable of delivering the same performance.

The current engine is called the Renesis and it has some developments, which are designed to reduce those perceived disadvantages of fuel consumption and high carbon dioxide exhaust emissions. On the high powered version there are three intake ports, with electronically controlled rotary sleeve valves and an electronically controlled throttle valve. The exhaust ports are now positioned on the side of the rotor housing, which eliminates an overlap in the opening of the inlet and exhaust ports. The exhaust ports are much larger than on previous engines and remain open for a longer period. This Renesis engine has a capacity of 1308 cc and delivers 170 kW, which gives the RX8 a top speed of 146 mph (235 kph), with a combined cycle fuel consumption of 24 mpg (11.4 lt/100 km). Today things have moved on considerably and perhaps Mazda have not moved quite as far as some of the others. The Ford Focus ST for instance delivers 166 kW from a 2522 cc, five cylinder turbocharged engine. This gives a top speed of 152 mph with 0-100 kph acceleration in 6.8 seconds and a combined cycle fuel consumption of 30 mpg. The BMW 6 series coupe, offers a variety of engine options, but for the same 24 mpg combined cycle fuel consumption you get a 4,799 cc V8 delivering 273 kW for a top speed of 155 mph and 0-100 kph acceleration in 5.1 seconds.
Certainly on a specific output basis, nobody comes near Mazda’s incredible 129.969 kW/lt, but perhaps with the addition of supercharging or turbocharging, they could extract even more power or reduce fuel consumption. Even if they do not, here in Ireland, where an avaricious government extracts huge amounts of road tax from motorists, based on the capacity of their cars’ engines, the Mazda enjoys an advantage due to its smaller capacity engine. However, even then the greedy government step in and grab more, as although the capacity of the RX8 engine is 1308 cc, the government demand the same amount of money as if it were a 1744 cc engine. This no doubt to pay for their huge salaries, massive increases and very, very generous pensions, not to mention sickening performance bonuses, when the system they administer is daily falling apart.
Externally my test car was finished in a stunning metallic bright red. Inside it had red and black leather upholstery to give a very attractive and luxurious finish. Unlike most 2+2 sport coupes, where climbing into or out of the two rear seats is a major obstacle, the RX8 has two rear doors to completely simplify the operation. Although they are hinged along their rear edge, they are not a safety hazard, as they can only be opened when the associated front door is open. It is necessary to enter from whatever side you will be sitting, as a substantial centre tunnel separates the two seats.

There is much more legroom in the rear seats than the picture above would suggest. The front passenger seat is in fact fully back on its runners. If you look at the driver’s seat cushion you will see that it is quite a bit further forward. That prominent centre tunnel houses three covered storage spaces, one for the two front seat occupants and the others for the two rear seat passengers. When the covers are slid open, there are two cupholders for front seat occupants, two for rear seat passengers, plus a large but shallow storage tray for the rear seat passengers. Then if you need even more space, the ski hatch opens to reveal a storage space on its underside. This ski hatch locks from inside the car, but it can also be easily removed when unlocked. Finally the front seat passenger has a large storage box in the facia.

Heating is provided for both front seats, with the switches conveniently located on the centre tunnel, just ahead of the covered storage/cupholders. The driver’s seat is electrically adjustable for reach, height and backrest angle. The steering only adjusts for height and has audio controls on the left hand horizontal spoke. The centre console contains the audio system and the heating/ventilating air conditioning controls. A digital panel at the top of the centre console, above the audio unit contains a clock, audio information panel, air conditioner information section and an outside temperature indicator. The exterior rear view mirrors are electrically adjustable and the windows in the two front doors are electrically operated. The windows in the two small rear doors are hinged at their forward edges and open outwards. Each sun visor incorporates a covered and illuminated vanity mirror.

The main instrument binnacle is under a curved hood directly behind the steering wheel. It houses three round faces. That on the left gives an analogue reading of the engine oil temperature at the top of the face, with a digital recording of the trip and total distance recorders at the bottom. The centre face has an analogue presentation of the engine speed on the left hand circumference, with a digital indication of the road speed lower down on the right. The speedometer will give its recording in either miles per hour or kilometres per hour at the press of a button. This is particularly convenient on this island of ours, where kph is the preferred official standard in one section of the country and mph is used in another part. If you cross the border, in either direction, it is imperative that you are aware of your exact speed, if you wish to comply with the indicated speed limits. The right hand face gives the engine temperature at the top and fuel level on the right, both in analogue form, with a series of warning lights for other necessary information.
I found this presentation particularly attractive and convenient to use. In these times, where the authorities have an obsession with speed, it is vital to know your exact speed whenever required. A rough approximation will no longer do. By the same token a needle sweeping around very rapidly in either direction lets you know exactly how hard the engine is working and over a period this is confirmed by a rise or fall in engine oil temperature. On the other hand a drop in the fuel level indicator merely means you will be sending the government and the oil producers laughing all the way to the bank, sooner rather than later.

When I last tested a RX8, away back in March 2004, I said that this was a driver’s car through and through, that delivered pure driving pleasure. Nothing has changed in the intervening period to make me change my mind. It has a scintillating performance and goes about delivering that performance in a quiet, refined sort of way. It is perfectly at home in city traffic, but it just loves the open road, where you can let it deliver that latent performance to the full. That little gem of an engine just loves to rev and it sings along, oh so sweetly and effortlessly, all the way to its 8,200 rpm plus limit. Progress is helped by the smooth and precise, six speed gearchange, but I did find selecting reverse could be a bit hit and miss if you were in a hurry.
While the ride was firm, in spite of those 45 profile tyres, it never appeared to be overly harsh or bumpy. You do, after all, expect a firmer ride from a potent grand touring car like the RX8. The steering was geared to give three turns from lock to lock, which is in the comfort zone, but on the RX8 it had a certain weightiness, which made the driver feel that he/she was fully in control at all times. The electrical power assistance, took all the hard work out of slow speed manoeuvring in tight places, but out on the open road, it let the driver feel that he/she was doing the work.

Performance is what buyers both demand and expect form a 2+2 sports coupe like this. The RX8 delivers in full measure. Always assuming you can find a road where it is legal to do so, you can cruise along at a top speed of 235 kph (146 mph). Of more use is its blistering acceleration, capable of whisking you from a standing start to 100 kph in a brief 6.4 seconds. That should put you firmly on pole position in the daily stop lights grand prix, provided of course the car alongside you is not a BMW M3 coupe, which manages the same feat in 4.8 seconds, but then it does have a 4.0 litre V8 with twin turbochargers under the bonnet. Perhaps all that BMW does, is to make you realise, just what a gem your little 1308 cc twin rotor Renesis engine really is !
Gentlemen, I am told, prefer blondes. I have also been informed that 2+2 sport coupe drivers, frequently play golf. I can never understand why, as if you have a superb machine like the RX8, surely you will want to spend your leisure time driving it ! However, all you golfers out there, rest assured that your golf bag and your trolley will fit into the RX8’s boot.

If on the other hand, you want to get your enjoyment from actually driving and decide to do a bit of touring, the boot should be capable of holding the reasonable luggage requirements of two adults. It is not quite as big as you would get in most, medium size, family hatchbacks, but it should present no difficulties, unless of course you are accustomed to taking the kitchen sink with you when you go on holidays. There is, unfortunately, one major problem, the RX8 does not carry a spare wheel of any sort. Instead the company give you an electric air compressor and a bottle of latex foam. While this may be an acceptable solution when you are just running around the suburbs, it is totally useless when you are touring. Punctures and blow-outs do not only happen during working hours in those parts of the world where 45 profile tyres are available from every corner shop ! When you do go touring, make sure you carry your AA membership card with you, as it is a lot more useful, if you get a puncture or blow-out, than that can of latex will ever be.
Finally, if you look at the fuel consumption solely in relation to the size of the engine, then “Yes” it is high. However, if you look at it in relation to the performance delivered, then “No” it is not out of line with cars delivering a similar level of performance. This is something you are going to have to decide for yourself. In this instance it could well be a case of one man’s meat being another’s poison. For me it offers an excellent balance of performance and driving pleasure, with luxury, comfort and attractive good looks, so that its actual fuel consumption would not be a deciding factor in my decision to purchase or to look elsewhere.

Technical data

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