Mazda Xedos 9 Miller 2.3 1998

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xedos9_003.jpg


Mazda has always sought to do things its own way - not only did it persist with the rotary engine for 20 years, but right now it can be found completely eschewing the industry trend for small capacity, blown engines in favour of more tractable naturally aspirated units - and the Xedos 9 was yet another one of the company's unique take on things.

First, the Xedos 9 was a very rare attempt at a Japanese executive car - built to take on the BMW 5 Series and Mercedes E-Classes of this world. You can count these on the fingers of one knee and the successful ones are even rarer - more so in North America with the Toyota Camry, but just about every other one of the rare attempts (Nissan QX, Mitsubishi Debonair, uhhh...) had failed to that point.

Secondly, the car was intended originally as the flagship to a new Mazda sub-brand, Amati. Japanese brands were having a bit of an identity crisis at the time, from which we got Infiniti (Nissan), Acura (Honda) and Lexus (Toyota), but Mazda was fiendish for it. Alongside the Autozam (compact & sports), Eunos (sports) and Efini (luxury sports) brands - some of which also inexplicably sold Citroens - with which Gran Turismo fans will already be aware, it had planned a full luxury brand named Amati. This brand was to sell the cars that eventually became the Xedos 6 (Amati 500), Xedos 9/Millenia (Amati 800) and the large, RWD Efini MS-9/Mazda Sentia (Amati 1000), but the venture failed at the last minute even after the dealerships had been fitted out for it.

But the most interesting part of the Xedos 9 is the engine...

MX3Miller002.JPG


Although the platform was unique to the Xedos 9, it used the classic Mazda K V6 engine range you could find in other Mazdas of the time. The little K8, a 1.8 powering the Mazda MX-3, was the first of the units. The KF was a 2.0 version, present in the 323, Xedos 6 and, in Europe only, this Xedos 9. The majority of Xedos 9s worldwide used the 2.5 litre KL variant, also found in the Ford Probe and Mazda MX-6 amongst others - but it's the flagship engine that holds the interest.

Only barely related to the rest of the range - by pretty much the engine block - was the 2.3 litre supercharged Miller Cycle engine, the first and for a time the only Miller Cycle engined car in the world and one of only three ever made.

xedos9_002.jpg


The conventional petrol engine cycle - the Otto Cycle - is suck-squish-bang-blow. In the first part of the cycles the piston travels down the cylinder with the intake valve open to suck in the fuel-air mix, while in the second the piston travels back up the cylinder with the valves closed to compress it ready for ignition. The Miller Cycle deviates from this slightly, by allowing the intake valve to remain open for a full 50% of the piston's upward stroke. Why doesn't the fuel-air mix get driven back out? There's a supercharger keeping the intake pressure higher than the cylinder pressure!

What's the purpose of this then? Well, the fact that the piston's expansion stroke is twice the length of the compression stroke means that the thermal efficiency of the engine - the amount of energy expended squashing the fuel compared to the amount extracted by exploding it - rises, increasing fuel economy. The net result was that the 2.3 Miller produced more power and torque than any other K Series V6 (up to 230hp and 230lbfft depending on emissions equipment) to pull the 1.7 ton Xedos 9 to 60mph in around 7 seconds and cruise at 34mpg on the motorway, despite a pigiron automatic gearbox. It was still a Mazda though and could shuffle through a handling course in a manner that would surprise the unwary - Mazda claimed that the Japanese market Millenia with the optional 4 wheel steering could out Elk-test the Nissan Fairlady Z...

Though the car was originally introduced in 1993, the 1998 facelift made a few improvements - largely to the slightly stunned front end - and since I owned a 1998 car, that's the one I want!

Oh, here's mine:

MX3Miller001.jpg
 
Nice car, fun and interesting information, so I can't find any reason to not vote on the car, I love it :P Your marketing of the car caught me!
 
Your marketing of the car caught me!
Bit of disclosure... mine doesn't look like that any more...

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But to be fair, that's because I bought it for £700 just for the engine. It had been in a somewhat recent crash (see the foglights in the first post) and was both inexpertly repaired and knackered underneath.

I did drive it 200 miles first though and it was hilarious. The 0-60mph time is supposedly 7.5s, but it didn't feel like particularly rushed - it just built up speed entirely linearly. It also kept doing it above that. It tackled my local "being a bit of an idiot" road without any fuss too.
 
Bit of disclosure... mine doesn't look like that any more...

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But to be fair, that's because I bought it for £700 just for the engine. It had been in a somewhat recent crash (see the foglights in the first post) and was both inexpertly repaired and knackered underneath.

I did drive it 200 miles first though and it was hilarious. The 0-60mph time is supposedly 7.5s, but it didn't feel like particularly rushed - it just built up speed entirely linearly. It also kept doing it above that. It tackled my local "being a bit of an idiot" road without any fuss too.
Oh OK, so the engine is in the white car now? If so it must be a fast little car now?
 
Engaging car, but from a GT perspective, I wish it had FR layout, it would be appropriate alternative to current Aristo, Chaser or Skyline V35 luxury machines (with a bit of tuning, of course). I think the only Mazda model capable of doing this is the similarly powered Mazda Sentia. The Xedos seems to be a good match for the Taurus SHO, I doubt it would lose so easily...

From an usual perspective I salute the pioneer of this technology, it is a wonderful car. I just wonder how reliable this engine really is, has anyone driven it long enough to know?
 
Engaging car, but from a GT perspective, I wish it had FR layout, it would be appropriate alternative to current Aristo, Chaser or Skyline V35 luxury machines (with a bit of tuning, of course). I think the only Mazda model capable of doing this is the similarly powered Mazda Sentia. The Xedos seems to be a good match for the Taurus SHO, I doubt it would lose so easily...

From an usual perspective I salute the pioneer of this technology, it is a wonderful car. I just wonder how reliable this engine really is, has anyone driven it long enough to know?
Just because it's FWD doesn't mean it would make for an inferior car.
 
Just because it's FWD doesn't mean it would make for an inferior car.
Nobody said it would be inferior, (albeit given the car's power to weight ratio and year of production, apparent limitations cannot be neglected), I just think it would receive more feedback from players as a FR car since hardly anything new was introduced to the series to cope with Japanese luxury examples I mentioned previously. That way you could merge unique technology with utility in the long run.
 
Nobody said it would be inferior, (albeit given the car's power to weight ratio and year of production, apparent limitations cannot be neglected), I just think it would receive more feedback from players as a FR car since hardly anything new was introduced to the series to cope with Japanese luxury examples I mentioned previously. That way you could merge unique technology with utility in the long run.
The way you put that last post made it seem like you were saying so.
Engaging car, but from a GT perspective, I wish it had FR layout, it would be appropriate alternative to current Aristo, Chaser or Skyline V35 luxury machines (with a bit of tuning, of course).
Besides, all the more recognition for the car here if hardly anyone uses it.
 
Xedos 6 and 9 were classic designs (the best 4-door cars in shape ever from Japanese automakers imho). They were also of very high quality in construction techniques and materials. They didn't sell much just because in this category (luxury sedans) most people think of prestige and this leads to the badge the car carries. Mazda is sadly very small to go against Merc, BMW and Audi. I have the magazine of AM&S from a compasion test with Xedos 6 v6, Audi 80 2.4, BMW 3.20i and Alfa Romeo 155 2.5 V6 and Xedos wins even for the german editor. It even had the best standard equimpment of all, security features included. A very impressive product for such a small company. Japan's economy suppression brought Mazda down hard and the rest is history.
 
We do need some more K V6 powered cars to go with that Lantis. This, an MX3, and an MX6 would be awesome to see (especially with Mazdaspeed parts).

I keep forgetting these are 2.3Ls. I keep hearing about people using Millennia S rods for boosted KL builds, and think that it has KL displacement. Its just the stroke that's the same between them.
 
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