Sunday, August 18, 2019

Solar-powered bus

This electric urban shuttle bus was made in Brazil, with a Mercedes-Benz O-500M chassis converted to electric by Eletra, a company specialized in electric drivetrains for heavy commercial vehicles that used to be mostly known for its serial hybrids but now supplies more full-electric systems catering to the trolleybuses of São Paulo city. This one specifically resorts to solar charging for its batteries bank, and is undergoing tests at the Santa Catarina State Federal University (UFSC - Universidade Federal de Santa Catarina) operating regular routes between its main campus and the Sapiens Parque, both in the Florianópolis island.
The body is a Marcopolo Torino Low-Entry, very similar to some Diesel-powered ones that operate regularly in my hometown Porto Alegre, while the overwhelming majority of the urban bus fleet in Florianópolis is front-engined with raised floor. Some differences between this one and a normal bus are mostly noticeable on the roof-mounted battery trays and solar panels, while the cockpit has a few different buttons, a rotary dial instead of the shift buttons for a normal automatic transmission, and the absence of a tachometer.
The electric motor is made by Weg, a company that is headquartered in Jaraguá do Sul, Santa Catarina state, but the electronic controls are developed in-house by Eletra, while the batteries are imported. The chemistry of batteries have been a complex matter, not just due to the improvements on the energy density required for mobile applications such as a vehicle but also because of factors such as the environmental impact of its end-of-life handling nowadays frequently referred to as "reverse logistics". Lithium batteries are not as easy to recycle as Lead-Acid ones which are still more common powering the accessories and the electronic controls in a more conventional vehicle with an internal-combustion engine.
One thing I can't deny, this bus got me thinking about some previous opportunities to develop local technologies for electric vehicles, including batteries with a higher efficiency back in the day when it was either Lead-Acid or those highly toxic Nickel-Cadmium ones. It's impossible to neglect the efforts of João Augusto Conrado do Amaral Gurgel, the same developer of a local attempt to replace the Beetle in the '80s, who also researched on batteries for EVs which he considered more promising than the ethanol despite his good relationship with the '64-'85 military government more supportive to ethanol. I'm sure it would be interesting to say the least if Gurgel's tetrapolar batteries get replicated with modern battery chemistry in order to improve its energy density...

Thursday, August 15, 2019

Brazilian Volkswagen T-Cross: surprisingly the cheaper engine not available on the local market

Recently introduced in Brazil, the Volkswagen T-Cross had been available only with turbocharged engines also fitted with direct injection, either the 3-cylinder 1.0L or the 4-cylinder 1.4L of the TSI range. However, for some regional export markets such as Argentina and Uruguay, the 1.6L MSI still naturally aspirated and with port injection is the only one available. There were times when Brazilian versions of certain models had the simpler engines, while the ones available in neighboring countries were more sophisticated, so it's somewhat surprising to see it going the other way around. Possibly the fact that both Uruguay and Argentina don't have such a strict displacement-tiered vehicle taxation structure as the one enforced in Brazil, most of the Europe and China renders an older engine with a greater displacement more competitive than the 1.0TSI for the entry-level versions, even though at least the 1.4TSI could eventually make its way on to the export markets for the Highline trim. At least in Argentina, it's also worth to notice the popularity of CNG aftermarket conversions, for which the port-injected 1.6L MSI is easier to implement than the TSI range, even though both the 1.0L and 1.4L TSI engines are available in a TGI trim optimized for CNG while retaining the ability to use gasoline on limp-home mode.
Another aspect to consider is the eventual altitude compensation provided by a turbocharger, even though the turbo-lag becomes somewhat more noticeable further above the mean sea level. Uruguay is comprised mostly of flat lands, so this effect is mostly negligible, while Argentina also features some stretches of hilly terrain on its part of the Andean Mountains. Among other regional export markets, Paraguay and Mexico are also relevant to consider when it comes to the difference between some eventual suitability of different engine layouts on each market. Versions available officially in Paraguay are fitted with the very same TSI engines used in Brazil, including the ethanol-capable "flexfuel" trim, while in Mexico there is some rumor about which engines will be offered, and some sources mention the 1.6L MSI to be more likely to become available there and eventually supplemented with the 1.4L TSI to become available for the higher trims. But in the end, considering the differences between the tax structure in Brazil and export markets, the seemingly outdated yet cheaper 1.6L engine is still clearly favored over smallest TSI on regional export markets where the T-Cross is sourced from Brazil in order to benefit from the Mercosur and other trade agreements.

Wednesday, August 14, 2019

4 reasons why sidevalve/"flathead" engines could make a comeback

Sidevalve engines, also frequently mentioned as "flathead", have been relegated to the past at least since the '50s in the automotive market. With one of the longest-lasting series with such valvetrain layout being Chrysler's flathead-six, which soldiered on from 1924 to 1960 in American-made civilian cars and trucks which included the '51 Dodge Kingsway, up to the '70s for some military vehicles and other specialty applications, and at least until '61 in Argentina, it fell out of favor mostly after tetraethyl-lead became a popular anti-knock agent for gasoline, allowing for higher compression ratios which were easier to implement on overhead-valve engines because of their combustion chambers not advancing to the side of the cylinder head where the valves would open. Despite being usually portrayed as unsuitable to meet requirements of a modern driver, a sidevalve engine has at least 4 good reasons which could still render an eventual comeback of it somewhat desirable.

1 - ease of servicing: with fewer parts, and some critical componets easier to reach whenever some technical intervention becomes required, it also saves time and thus enables the vehicle to resume its usual operating routine sooner. Even a full engine overhaul, if it ever becomes required during the useful operating life of a vehicle fitted with a sidevalve engine, takes less time and fewer raw materials are needed because of the lower amount of parts in need of a replacement;

2 - lower revving: leading to advantages such as a longer engine longevity, besides being optimized for low-end torque which enables keeping a comfortable cruising speed on a higher gear with fewer RPMs, the peak torque closer to idle may also render it easier for novice drivers to learn how to use a manual transmission (which nowadays with so many automatics might serve as somewhat of a passive anti-theft device). Obviously can't compare so accurately to a more rev-happy modern engine, but the greater lower-end torque renders a larger-displacement sidevalve operating at lower RPMs paired to a higher gear ratio suitable to perform the same tasks with fewer stress;

3 - low manufacturing cost: with fewer parts due to its simpler designs, and some such as the cylinder head being noticeably simpler than what would be found on any other 4-stroke engine, a sidevalve could appeal to some conservative and budget-conscious buyer. For work vehicles such as trucks, which are also usually not so burdened by a displacement-biased tax structure which is prevalent in Europe and South America, this advantage may remain easier to exploit;

4 - possibly beneficial side-effects of a lower compression ratio: in a time when most spark-ignited engines now feature direct injection in order to enable a sky-high compression ratio and lean-burn leading to a more Diesel-ish fuel efficiency, the more conservative compression ratio on a sidevalve may not be so bad at all. As it leads to a lower aerodynamic heating of the intake charge, a leaner air/fuel ratio won't increase any likelyhood to pre-ignition/knocks, all while it also avoids the increase on Nitrogen oxides (NOx) which now plagues most direct-injection gasoline-powered or "flexfuel" engines able to operate on ethanol. So, even with a more affordable and easier to service conventional port-injection system replacing the carburettors which prevailed on the sidevalves' days of glory, some competitive fuel efficiency may not be out of question. And if some alternate fuel such as CNG is used, which is not the case on the collector vehicles I usually see that still feature their original drivetrain such as this '53 Dodge Kingsway, it's roughly impossible to trim the mixture so low to still enable combustion amidst an increased risk of overheating usually associated to an excessively lean air/fuel ratio;

Thursday, July 18, 2019

Good-looking pressed-steel wheels?

Most often, the aftermarket options catering to those who seek for better-looking wheels are made out of light alloys, and usually either die-cast or forged. Pressed-steel wheels are still usually standard for entry-level models or versions of larger vehicles, but not often so appealing. It did surprise me to see this first-generation Chevrolet Prisma with a pressed-steel wheel that reminded me the Mangels-brand ones which were a popular aftermarket option for trucks and SUVs in my homeland Brazil in the '90s. Sure a small sedan is not the vehicle I would expect to see with a set of those, maybe it was borrowed while a stock wheel was being repaired after getting bent. But anyway, since so many SUVs and small coupé-utility trucklets have high sales volumes, maybe such wheels could've been somewhat appealing to those who either need something more resistent and easier to fix than an alloy wheel or want their brand-new mall-rated SUVs to look tougher...

Tuesday, July 16, 2019

Volkswagen's EA111 1.0L 16-valve turbo, an early, yet failed, approach to downsizing in Brazil

One of the most controversial engines ever, the turbocharged 1.0L version of the EA111 which was only fitted to the Gol and Parati (pictured) between 2000 and 2004 was only available in Brazil. The reason behind its development was the tax bracket that benefits engines up to 1.0L in the local market, which is the only reason it ever became available. In contrast to naturally-aspirated versions of the same engine, either a 2-valves per cylinder SOHC (not available for the Parati) or a 4-valves per cylinder DOHC, the Turbo also featured variable valve timing on the intake. A quite sophisticated engine, it was meant to become somewhat of an indirect replacement to the 1.6L gasoline/petrol version of the EA827 series (the ethanol-powered version remained available as the sole 1.6L engine for the Gol and Parati for a brief period), but ended up rejected by the average buyer of the Gol and Parati range due to its complexity and more demanding oil specifications which were sometimes not observed so strictly by its owners. Rated at 112PS at 5500 RPM and 155Nm at just 2000 RPM, it had a single PS in advantage power-wise to the 2.0L EA827 rated at 111PS at 5250 RPM, which on the other hand still had a higher torque rating of 166Nm at 3000 RPM. And even though the 1.6L EA827 was disfavored on both power and torque with 92PS at 5500 RPM on the gasoline version or 97PS with gasoline and 99PS with ethanol at 5750 RPM on the early flexfuel trim, while the torque ratings were 135Nm at 3000 RPM for the gasoline-only and 136 to 140Nm with either gasoline or ethanol on the flexfuel, the right gear ratio could make such disadvantages less noticeable on normal operating conditions. Plus the fact the 1.6L and 2.0L were in fact cheaper to manufacture, owing much to the SOHC head with just 2 valves per cylinder and the natural aspiration, when the tax advantage for 1.0L engines became narrower around the end of 2002 the Turbo 16V engine started to not make so much sense as it seemed to make at the time of its release, which combined to the reliability records affected at some degree by a lot of maintenance neglect prevented further usage of this engine on other applications. Even the naturally-aspirated version of the 1.0L engine became less sought after by then, with its 69PS at 5750 RPM and 90Nm at 4500 RPM. It's also worth to notice this early approach to the downsizing was performed when direct injection was not so widespread on spark-ignition engines as it is nowadays, so in order to prevent knock it doesn't run so lean as the present-day 1.0TSI does...

Friday, June 21, 2019

Are motorcycles and tricycles any likely to effectively replace a small car for certain users?

In 3rd-world countries, small-displacement motorcycles emerged as a practical tool due to their lower purchase prices and running cost compared to subcompacts, even though they would not deliver the same hauling capacity, not to mention weather protection which is not even an option. Enhancements for cargo capacity available are usually trailers and sidecars, which may lead to some differences in handling and performance but might be cost-effective enough to address some bare necessities.
Their crudeness however, now renders such devices more suitable for cargo hauling. Even the side-car, which used to be widespread in other countries even for passenger carrying before the emergence of the so-called "people's cars", is now mostly used for other purposes. Sure being exposed to weather and elements might not be a desirable feature for the overwhelming majority of car buyers, not to mention the stigmas that surround side-cars not only due to the perception of a motorcycle as somewhat "inferior" but also their usage by the Nazis during World War II.

Even though small cars are widespread on a worldwide basis, with low-cost models such as the Renault Kwid specially developed catering to budget-constrained markets such as Brazil and India, the higher safety requirements and stricter emission rules end up impacting their retail price more than what it does for motorcycles. Sure it's like comparing apples and oranges, but the proposals for an affordable "people's car" that may be rendered either uneffective to address all (or at least most of) the needs of what might be the only motor vehicle available for an entire household. So, the enhanced possibilities of covering much of those needs with a side-car, which may also lend itself to a higher degree of customization in order to serve better to different operators's requirements.

Less stringent emission rules have even allowed entry-level models such as the HaoJue DK 150 and Chopper Road 150 to keep some quite outdated approaches to the mechanic such as retaining the carburettor. Even though EFI has proven its value as a fuel-saving feature, the ease of servicing without overly-sophisticated tools still keeps the carburettor somewhat desirable for some buyers. It may be set to be ultimately phased out on most markets in a few years, but is far from being the only cheaper-yet-effective feature on motorcycle engine tech. Since many of the entry-level ones retain the single-cylinder layout, even air-cooling might be sufficient for most uses, despite the fact it doesn't provide some greater precision on thermal management that could be achieved with liquid-cooling.

Tricycles are also an option to consider, even though their legal status might be subjected to different views on how a motorcycle or similar would be classified. Models fitted with a handlebar and all-open cockpit such as the Can-Am Spyder are clearly more relatable to a motorcycle, while some random Chinese cargo tricycle with more car-like controls might comply to all the same standards applied to a 4-wheeled vehicle of comparable capabilities. Some importers of those Chinese tricycles even have them classified as agricultural machinery in order to circumvent some of those regulations, with the corresponding restrictions applicable to their traffic on public roadways preventing some broader acceptance among the general public.

It's also worth to mention tricycles might provide different degrees of weather protection to operators, and versions meant for either cargo or passenger service are available too. However, the most basic utilitarian ones might not provide the best performance to cover all the needs for private users who could require some more spirited performance and higher range to deal with occasional highway stretches. Despite some modern motorcycle engines being suitable even to a regular compact car, some tricycles such as the ones made by Bajaj in India resort to ancient engine designs with narrower RPM bands which render their power and torque figures less effective under certain circumstances when either a higher-displacement engine or a more rev-happy one could address them more effectively.
Even though some issues that may compromise the chances for a motorcycle or tricycle to become an effective alternative to so many ill-fated "people's car" projects, they may still cover reasonably the needs of many commercial operators. Even for passenger-carrying such as taxi and more recently the apps such as Uber, the easier maneuvering on tighter spaces could turn into a valuable asset, but some regulations concerning the size of vehicles to be allowed as taxi in different cities might lead such option to be not so likely to get widespread so quickly. Arguments such as decreases to emissions and fewer traffic congestions could be presented in favor of tricycles, but in the end might be neglected by regulators and received with fierce criticism from taxi drivers. Well, most of the time even one of those Bajaj tricycles could get the job done as effectively as a conventional taxi from my hometown Porto Alegre, but other factors such as easier resale are also accountable favorably to a sedan such as the Fiat Cronos which may not be seen as a mere bare-bones workhorse that might be eventually perceived as more likely to have been subjected to severe usage and occasional maintenance neglect.

Sure the business opportunities are now less promising for the development of subcompact cars with a small footprint such as the Gurgel BR-800 and Supermini which could serve very similar purposes than a tricycle of a motorcycle with side-car, both a handful of technical issues and the overall perception of the customer regarding subjective factors such as prestige might lead to fewer chances for passenger cars to be as effectively replaced as some small commercial vehicles were.

Wednesday, June 19, 2019

Would a 2-cylinder engine still make sense for the car market?

A feature which used to be found on some of the most interesting small cars from the postwar, such as the Citroën 2CV and the Fiat Nuova 500, a 2-cylinder engine used to be seen as nothing but a cost-cutting measure by most customers, who didn't seem to figure out their practical advantages so well...

The amount of cylinders used to be perceived as a prestige feature, dictating some guidelines to the development of cars such as the original Morris/Austin Mini for which a 4-cyl had to be mounted transversely for space-saving, in order to enable the majority of the floorpan to be devouted for the passengers and luggage, ultimately turning this layout into an industry-standard for small front-wheel drive cars. Most front-engined hatchbacks were following such in the '90s, when Gurgel introduced to the Brazilian market its Supermini resorting to a longitudinal flat-twin engine and rear-wheel drive. In this case, not only fewer cylinders but also their arrangement were relevant for space-saving and to keep a 50-50 weight bias, which would increase towards the rear axle according to the load and improve traction over rough terrain.

Another aspect, most noticeable on flat air-cooled engines, is the cooling efficiency. Taking the example of the VW Beetle with its flat-4 and once again the Citroën 2CV with a flat-twin, the rearmost cylinders of the Beetle would only get cooling air which had previously exchanged heat with the other cylinders, while for a 2CV the cooling flow becomes more homogeneous between the only 2 cylinders. Results may obviously vary among other cylinder layouts, but a twin is still usually better than others when it comes to this aspect.
Considering the success of the Citroën 2CV in Argentina back in the day, which could be perceived as a reason to believe 2-cylinders wouldn't be a taboo there, it's quite surprising to figure out newer models focusing on emerging markets such as the C-Elysée could benefit from such approach, even though very unlikely to be a longitudinally-mounted flat-twin similar to the one which was fitted to the 2CV. It's worth to notice that a 3-cyl 1.2L gasoline-powered engine is available on some countries besides the 1.6L gasoline and Diesel options currently available in Argentina, which may not sum it all but does reinforce the perception that fewer cylinders in a vehicle meant to be somewhat versatile and utilitarian is still acceptable, and maybe such approach is not taken one step further because more sophisticated engines which would increase economics of scale as they're more easily accepted also on vehicles with a supposedly fancier marketing approach.

Considering the widespread perception of engines with fewer cylinders for a given displacement to be less rev-happy, and favoring low-end peak torque over high power throughout a broader RPM band, it's worth to consider not just the impact such matter would cause to overall performance but also the recent trend of downsizing overlapping with some downrevving too. Examples such as the Chevrolet Trax, known in my homeland Brazil as Chevrolet Tracker, show it quite clearly after the 2017 facelift which led to the 1.4L turbocharged engine to replace the previous 1.8L one, both being 4-cyl. Considering the specs for Australia, where both engines are still offered, both are rated at the same 140 horsepower (103 kilowatts), with the naturally-aspirated 1.8L peaking it at 6200 RPM while the 1.4L does the same at 4900 RPM already. Torque rating for the 1.8L is 178Nm (131lb.ft.) at 3800 RPM, while the 1.4L delivers 200Nm (148lb.ft.) between 1850 and 4900 RPM. Sure the turbo is a key factor to the peak torque delivery being flat across a broader revving range, so maybe even a hypothetical 2-cylinder 1.5L based on the ancient Chevrolet 4-cyl "153" engine which used to be a mainstay in Brazil and South Africa could eventually be viable, despite the amount of cylinders remaining seen as a prestige feature in Brazil...

Now looking at Ford, which is having some rough times in Brazil once again, the EcoSport now only has a 4-cyl engine in the Storm 4WD trim, namely the 2.0L Duratec Direct, while other versions are switching from the 4-cyl 1.6L Sigma to the 3-cyl 1.5L Dragon. It's quite hard to compare Brazil and anywhere else, due to the history of automobile industry being totally indissociable from bad political decisions which often led to some unwise strategies among the locally-installed automakers. I'm sure some of the objections raised against the Dragon engine are more biased toward the perception of a 3-cylinder as an impoverishment which is still widespread on the customers' mindset. It's also worth to remind the turbocharged 3-cyl 1.0L EcoBoost which is standard for the US-spec EcoSport is not even available in Brazil, where a fiscal benefit led to this displacement range being more accepted among entry-level car buyers and becoming subjected to some stigma when it comes to other vehicle classes perceived as premium. I know it might sound pointless at first, but this is Brazil, and the SUV trend in a poor country has led even compact models such as the EcoSport to be regarded as somewhat aspirational, and then any step further on downsizing, downrevving or whatever else would become harder to sell despite offering some technical advantage besides a lower manufacturing cost...

Nowadays the model which could be better suited to a selection of 2-cylinder engines in the Ford range is the 3rd-generation Ka, also known in markets such as Mexico and India as Figo. The base engine in Brazil has been the 3-cylinder 1.0L Fox engine since its introduction in 2014, with other options being the 4-cylinder 1.5L Sigma until 2018 when the 3-cylinder 1.5L Dragon replaced it. Even though the model is also available in Europe which is a more developed market, its position as an entry-level econobox could justify an engine which would lead to a lower cost, not to mention the European customer being more open-minded toward fuel savings in this class compared to others who still consider the displacement and amount of cylinders as a matter of prestige. Considering the fewer internal frictions and pumping losses inherent to having fewer cylinders, such approach could eventually become also beneficial regarding the emission regulations in Europe which are getting more and more stringent.

Sometimes a technical approach which had been quite neglected for a while might end up being the best approach to overcome modern challenges, and this happens to apply to 2-cylinder engines. Sure it's not only an objective matter, with more subjective aspects also becoming relevant, but it doesn't justify the absence of such engine layout on most automotive markets nowadays.