Monday, November 09, 2020
Saturday, November 07, 2020
Monday, October 19, 2020
1 - the "twincharger": while the engine-driven supercharger might provide a reasonable boost from launch to around 3500 RPM, and then the exhaust-driven turbocharger does all the job when it comes to forced induction, it's worth to notice the increase on parasitic drag from the supercharger and its drive, which is somewhat more objectionable as it may be desirable to keep the engine at lower load during normal operating conditions driving on the speed limits. Since the presence of the supercharger is not taken benefit to allow the engine to operate within the Miller cycle, which resorts to a longer intake timing advacing through compression stroke in order to emulate the Atkinson effect while the forced induction prevents the charge air intake to escape, eventually it would make more sense resorting to the PowerPulse system fitted to the Diesel twin-turbo D5 engines which resorts to a compressed-air impeller for the turbocharging in order to overcome turbo-lag with the air being supplied through an electric-driven compressor on board;
2 - absence of flexfuel capability: due to the "sustainability" premises, it would make sense to have a provision for the vehicle to be capable to operate on a renewable fuel along the more usual gasoline, with ethanol capability being somewhat reasonable to expect from a modern spark-ignited engine. Not only it has a cleaner combustion process, turbocharged engines fitted with direct injection provide ideal conditions to narrow the efficiency gap per fuel volume between gasoline and ethanol, as they lead to a safer increase on compression ratio while operating with gasoline and easier cold starts while running on ethanol;
3 - keeping the same automatic transmission of non-hybrid versions: while it could either take benefit from the instant torque output of electric motors to get no gearbox at all, enabling them to act as a CVT just like Toyota and Lexus hybrids usually do through their Hybrid Synergy Drive setup, or to use some other automatic or automated-manual transmission more optimized for overall efficiency, it just retains the same 8-speed automatic shared with the non-hybrid T4, T5 and T6 versions. Sure it would be harder to expect the option for a manual transmission, as an automatic leads to a smoothier transition from EV mode to combined electric and gasoline power, but other setups predictably more in line with the usual expectations for hybrids would be more favored by fuel-efficiency and emission regulations;
4 - seemingly lack of motivation to benefit from a Freevalve design: even though the mainstream automakers usually tend to take breakthrough tech with a grain of salt, most noticeably when there is a need for a licensing from a smaller engineering outlet, its hybrid range would be a perfect receiver for the Freevalve technology, not only because it would allow the usage of a simpler port-injection and to get rid of the particulate filter, but also due to eventually making it easier to alternate from 4-stroke to 2-stroke under specific conditions as the presence of the supercharger could serve to provide a more efficient scavenging just like on 2-stroke Diesel engines.
Monday, October 05, 2020
2nd-generation Peugeot 208 made in Argentina: only one engine option doesn't match regional needs and preferences
While the higher purchase cost of a turbodiesel inherent to the increasingly sophisticated aftertreatment becomes troublesome for a country with a severely troubled economy as Argentina is at the moment, a strong market for natural gas conversions is more favorable to the EC5 and would also be to the basic naturally-aspirated EB2 due to the usage of port-injection, instead of the direct injection which is fitted to the turbocharged variants of the smaller engine. And since the 1.2L EB2 is slotted right above a more favorable displacement class up to 1.0L for taxation purposes in Brazil, just like the 1.6L EC5 does, it could be at a first glance rendered less competitive against the direct-injection turbocharged flexfuel 1.0L engine offerings from Chevrolet, Volkswagen and Hyundai and unlikely to set a foothold as the higher manufacturing cost of a downsized engine compared to a more traditional counterpart is not so easily amortized through a tax break, even though the Mercosur agreement gives Argentinian-made cars a different tax break in Brazil. It's also worth noticing similar models from other manufacturers which are available in Brazil in 1.0L naturally-aspirated or turbocharged and larger-displacement naturally-aspirated versions only go to Argentina with the biggest engine for the very same reason, as such more favorable taxation scheme is absent there.
While a naturally-aspirated trim of the EB2 could be more valued by Argentinian customers as long as the purchase cost remained lower and a manual transmission would be retained, and some turbocharged variants would be more appreciated in Brazil due to the technology and "sportiness" appeal with a good marketing perspective for the availability of both manual and automatic transmission options, retaining the EC5 and automatic-only becomes an objectionable one-size-fits-all approach. The total absence of turbodiesel options, which could at a first moment sound quite predictable as it's not allowed for cars in Brazil and nowadays seems too expensive for a small car in Argentina, can also be counted as another mistake somehow. Overlooking all the complexity of South American car markets as a whole, ignoring specific aspects of each country in the region and how to better address such conditions, often leads to a poor decision-making which may have a troublesome reflex on the actual marketing perspectives for an otherwise good product, and right now it seems to be what happens to the 2nd-generation Peugeot 208 even though it's too soon to be sure about it failing or receiving a better-adjusted selection of engines.
Sunday, October 04, 2020
Would a mild-hybrid version of the 1.3L Firefly engine make sense if Fiat ever brings the Strada back to Europe?
Sunday, September 27, 2020
Ford and the switch to 3-cylinder gasoline engines for the EcoSport: why not a 3-cyl turbodiesel too?
Thursday, September 17, 2020
Could it have avoided GM too much trouble with China if it insisted on rear-wheel drive for small cars?
Wednesday, August 26, 2020
Sunday, August 23, 2020
5 reasons why Volkswagen's attempts to get rid of naturally-aspirated engines haven't been so effective
1 - cost: even though in Brazil the Polo has a more prestigious approach than in Europe where it's seen as an entry-level model (disconsidering smaller vehicles which may not be suitable to serve as a family car), both markets are inviting to the 1.0 MSI, while in Brazil a recent increase in demand for automatic transmissions is also favoring the 1.6 MSI which is more affordable to manufacture than the 1.0 TSI. In some countries supplied by the Brazilian-made Polo, not even the hi-tech approach could favor the TSI, as the absence or non-applicability of displacement-biased taxations render it somehow cost-prohibitive compared to the 1.6 MSI;
2 - suitability to alternate fuels: while the direct injection may benefit the usage of ethanol, as it not only increases cold starting ability but also allows a higher compression ratio which otherwise could be troublesome while using gasoline, it becomes more expensive to convert to gaseous fuels. Even though LPG can be injected at the liquid phase through the stock fuel rail and injectors of the TSI engine when fitted with a suitable conversion kit, CNG requires either specifically-designed injectors which allow liquid-phase injection for gasoline and vapor-phase injection for natural gas replacing the stock ones or mounting the CNG injectors bridge at the intake manifold for port injection while a smaller volume of gasoline direct injection is still required in order to keep the stock injectors cooling and lube as they are directly exposed to the flame spread. When it comes to ethanol, the electric pre-heating of fuel became a standard for port-injection flexfuel cars in Brazil as a cold starting aid, somewhat analogue to what has already been done on Diesel engines which relied either on glowplugs located at the cylinder head or grid heaters at the intake manifold;
3 - maintenance: turbocharged engines are still perceived to be more sensitive to factors such as lube oil quality, even though using a lower-grade oil in a modern naturally-aspirated engine is not exactly a good idea too. And even though turbocharging technology also had to evolve at a high pace due to the prevalence of start-stop on newer cars in order to address tighter fuel-economy regulations in Europe and Japan also leading to more demanding conditions for the lubrication system, the higher thermal loads to which a turbocharged engine is submitted are undeniable. A lower cost of replacement parts for the fuel system of a port-injection engine is also valued by budget-conscious buyers;
4 - turbo-lag: nowadays it's not so critical as it used to be when downsizing started to be more closely observed as a step toward a future that didn't materialise, but the turbo-lag is still often pointed out as a determining factor for turbocharging to not become so widespread on entry-level compact cars. On the other hand, models above the Polo and its derivatives now feature only turbocharged engines which may be smaller in displacement than the 1.6 MSI such as the 1.4 TSI yet the low-end performance is not so bad even though it still takes longer to reach full boost in Mexico City than in Cancún due to the lower atmospheric pressure inherent to a higher altitude;
5 - a conservative public: in the markets where Volkswagen failed to promote downsizing throughout its entire range, the acceptance of turbocharged engines remaining more concentrated around models and versions within classes above the Polo, which renders it easier to find out the appeal of natural aspiration for conservative buyers who look at Volkswagen for an all-around commuter instead of some sportier model which would be supposed to require a more specialized maintenance.