The Mazda CX 5 seems to interest many people. The video about this car will be by far the most clicked of our 350 videos on youtube. Reasons for this could be the current difficulties of the company Mazda or the introduction of the Skyactiv technology. The latter will be here the topic, where we will focus on the announced innovations to the engines.
The opening statement sounds like a drumbeat. For the first time a petrol and a diesel engine is the same compression ratio. One had already suspected, because the trends of the petrol engines were increasing and steady were falling at the diesel. Let us take first the latter.
Of course, one can see such a low compression ratio only related to charging, otherwise the engine would only realize very little power consumption and by no means a good consumption. In this case, the turbocharger is also two stage, but really not much say about the boost pressures. However, a boost pressure reduced to 135 bar shows that here a compromise was received rather less in the direction of nitrogen oxides.
It's therefore fitting that the new engine neither needs DeNOx catalytic converter nor external exhaust gas recirculation. But even then the particularly high particle emission occurs here. Rather, one must worry to performance, torque and CO2emission, respectively fuel consumption. But there are indicated e.g. values around 400 Nm that neat is for a 2.2-liter engine. It may therefore be asked how this up to this point less expensive to produce engine can exist in the competition.
Thereto comes the fine tuning, hat characterizes modern engines with their manifold adjustabilities. Unfortunately, here we rely on information from the Mazda commentators, whose texts contain much company overhead. There is spoken from a special form of the piston bowl, the image can not really confirm. After all, it is indeed a fact that this new diesel engine has an adjustable outlet camshaft, the second novelty. Also one speaks a lot from the crank mechanism, now less under pressure and thus easier to run.
The new diesel engine runs slightly higher and has less internal friction. Its pilot and main injections are divided different and also changed in instant of time. So it may be possible that also by changing flow conditions, the engine do not get out of line compared to its competitors becoming increasingly stingy.
The first tests prove to be unfounded fears of a higher consumption. The diesel engine can compete well with the more efficient of its competitors, even if the announcement of a particularly low weight, during repeat measurement as not really proven. Complimented is the stoic propulsion power even of the less powerful diesel engine.
Much more we believe in this regard to the petrol engine. To control such a high compression that is something. It is already bound to our fuel quality, as for the North American market, it is probably not taken. Thus, although both engine types have the same compression, the problem for engineers is probably a completely different. To achieve low fuel consumption and enough performance and (also) torque, the problem is probably not here.
Apparently, the fine tuning was referring here to the avoidance of knocking combustion under all possible circumstances. Needless to say, that it is a naturally aspirated engine. Also, we mention the adjustable cams and camshafts just a matter of form. Mazda emphasizes much the exhaust system, which summarized first each two cylinders and then the two remaining strands. They must have been important, because the cat can then, of course, not flanged at the top of the cylinder head and is not quite as quick warm.
The performance values do not get downwards especially out of line. Even the rpm of max torque is still acceptable for a naturally aspirated engine. Here would be interesting, of course, the process at lower speeds. Here again is used the empty cliché technology of proven explainers at Mazda. Of course, they may make however no detailed explanations, e.g. for the competitors. Which will dissect such a "Skyactiv" car still early enough. Perhaps at this point is still important the keyword 'ion current measurement'.
In summary, you can probably notice that with a direct injection like this naturally scavenging methods are possible, without producing unburned exhaust. Due to the variable stroke adjustment of the cam can also be reduced the quantity of mixture, almost without touching the lambda. Still remains open, whether the engine goes in a lean mix mode and accordingly yet has a DeNOx catalytic converter, unlike the diesel. The internal engine admixture of exhaust gas is used at least.
In the test, the gasoline engine comes off not as well as the diesel. One miss features that would predestine him as a base engine for such an SUV. Otherwise, the not just polarizing design is praised and also the fact that one receives a lot of car for the money. Even the luxury equipment is a popular one, not always as a matter of course in the country of Mercedes, BMW and Audi.
The very good ride comfort does not seem to satisfy the request of the testers but the can not really make clear the reason for not always solid directional stability. Actually it is neither in the steering, even on the drive to find fault with anything. In turn praised the possibilities for loading of the CX-5 concerning the three-piece rear seat, the almost flat load floor and the with the tailgate rising cargo cover. 05/12
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