Monday, January 16, 2017

Is a 4th wheel really necessary?

For quite a long time, the private ownership of a car had been praised as a status symbol. Mechanical complexity and the inherently high maintenance cost had made it harder for lower-income Europeans to afford it, plus there was another risk of engine damage due to freezing of the cooling water when parked outside in the winter. In times when antifreezing radiator fluids were seen as quite of a sci-fi deal, the release of economy cars with air-cooled engines such as the Volkswagen Beetle and the motorcycle-engined BMW Isetta meant that it would finally become technically viable for many who couldn't afford havign a heated garage at home.
Even though the Isetta was not so conventional at all, being available either in the 4-wheel version with a narrower rear track in order to not require an open differential or in a 3-wheel version catering to markets where the register as a motorcycle led to a lower licensing cost, not just the perceived status of a car but also concerns about stability turned the 4-wheel into a more desirable option. The enhanced comfort in rain and snow was clearly an advantage compared to a motorcycle with sidecar, which until the postwar used to be the main alternative for those who needed an improvement to either the cargo or passenger capacity and couldn't afford to own a conventional car, but it's possible that showing off aboard something peceived as "superior" to a motorcycle could be an even stronger sales argument...

The same perception that led 4-wheel vehicles to be regarded as more desirable echoed to a much lower extent to commercial operators in a worldwide basis, to a point that certain tricycles such as the Piaggio Ape and its Indian derivatives even became praised as some sort of cultural icon. Advantages such as a lower fuel consumption and a fewer amount of components that would need replacements such as tyres, springs, shocks and brake pads are a valuable asset to enhance the profitability, and nowadays those seem to be more likely to increase the presence of 3-wheel vehicles as a cost-effective response to stricter environmental standards affecting the cars and light commercial vehicles market. Passenger applications are still a taboo in some countries, not just developed ones such as Australia and the United States but even third-world ones like my homeland Brazil where the Indian "tuk-tuk" grabbed more attention after being featured in an India-themed soap-opera but is still faced more as a curiosity than as an effective option to enhance urban mobility.
Naturally, the low performance of a "tuk-tuk" is a downside while looking for a vehicle suitable not just to city traffic but also to occasional road trips, with this kind of compromise being undesirable for customers who wouldn't afford to own a second vehicle dedicated to go through longer distances at higher speeds. On the other hand, pointing out the 3-wheel layout as unsuitable to road traffic without a compromise to the safety is not accurate at all, as it have been already proven by so many Volkswagen-based custom trikes. Inherent risks of the all-open seating area usually featured on them shall not be disconsidered, but are far from being reasonable grounds to rule 3-wheel vehicles out.

The popularity of small coupé-utilities, which raised from a low-cost alternative aimed at commercial operators to a somewhat trendy option for those who want to pose as a "gas-station cowboy", can be seen as a precedent to an eventual increase to the acceptance of utility tricycles among private users. It's already happening in Uruguay, where the lower purchase price and running cost of Chinese-made cargo tricycles with a fully-enclosed cabin featuring car-like controls have turned them into a viable option to replace badly worn-out older vehicles with comparable capabilities. The improvements to the fuel-efficiency are also noticeable, with a decrease in emissions as a secondary advantage. Sure there are some political and cultural factors that lead this option to a wider acceptance in Uruguay, ranging from the lack of a protectionist policy aimed at the nearly-defunct local auto industry to the higher degree of success in the "whitening" policies enforced in most South American countries right after the abolishment of slavery to a point that it's not so usual to spot a black Uruguayan (even a kid who tried to sell me weed a few years ago was white), but it doesn't seem impossible to eventually become more accepted in Brazil too. For those who either can't afford a 4-wheel vehicle or just look for some inexpensive commuter, it's not a bad choice at all.

Sidecars and some crude tricycle conversions became more widespread in Brazil in the last 10 years, mostly based on low-displacement motorcycles and catering to commercial operators but, due to the skyrocketing fuel costs and the scarcity of parking spots on the streets, the lower fuel consumption and smaller footprint have turned these alternatives more attractive to private users too. Once again the lack of weather protection is somewhat undesirable, but it still doesn't outweight the savings. While it's still more usual to see it used to deliver bottled water and propane, the popular perception of this device as a makeshift is quickly fading away. The outrageous prices of a brand-new car is also leading sidecars to become an alternative for novice motorcycle users looking for a small boost to the passenger capacity at a total cost that remains proportionately lower.

Unfortunately, the average mentality in Brazil goes beyond the perception of the car ownership as a matter of status, even though it's just a local penalty-box such as the Chevrolet Celta or an old import worn-out to the point that it would be more valuable if parted-out. The main reason for many people in Brazil to get a car is to show-off to neighbors or to the "gas whores", and there is always some lame excuses given when somebody's bad taste for cars is addressed. It's not unusual for Brazilian ricers to act like spoiled children and label every criticism as "envy", even if the money blown in their failed attempts to improve the looks of their rides could be better spent upgrading to a stock one of a higher segment instead, but it just serves to point that reasonability is not always treated as a priority by those looking to get a car.

Anyway, despite some calls for a performance improvement desirable to keep up with road traffic, and therefore increase their overall versatility, tricycles and sidecars have already proven their value as an asset to raise the efficiency of the urban mobility. So, in many circumstances, it's not a higher amount of wheels what could define which vehicle is "better".

Thursday, October 20, 2016

Why do I prefer a van over an SUV with a similar powertrain?

When it comes to car bodystyles, the SUV is among the most controversial ones. The acronym stands for sport-utility vehicle, but it's definitely arguable how sporty and utilitarian those pigs rigs are in a direct comparison to a van with a similar powertrain. For example, how could we justify a Toyota Hilux Surf/SW4/4Runner justify as a better option instead of a HiAce? Well, even though 4WD was not available for the HiAce through official importers in most markets, the success of those JDM versions with this feature as second-hand Japan exports in some Latin American and African countries may be a clear indication that I'm not the only one who would rather choose the van bodystyle. Be it for commercial purposes, extended family trips or leisure, there are many reasons leading this to become a more reasonable option.
Sure there are a few compromises, the most notable one being the cockpit and rear passenger door positions that would eventually not be in accordance to the export destination of a Tokyo-takeaway. Right-hand drive vehicles suitable to the left-hand traffic direction in Japan often have to go through a mandatory left-hand drive conversion in order to be allowed registry in countries such as Paraguay and Bolivia for example, even though the rear sliding door that was meant to be used in the curb side in a left-hand traffic such as Japan remains unchanged, thus becoming off-side for right-hand traffic which is prevalent in most of the Americas. At least in the continental mass, the only countries with traffic on the left side of the road are Suriname and the former British Guyana. Apart from those, only some island countries in the Caribbean such as Jamaica and Trinidad and Tobago keep the "English hand" traffic ordinance.
Another matter of concern regards to vehicle dimensions and off-road capability. It's quite predictable that a forward-control van is going to feature a longer front overhang, imposing some limitation to the approach angle, but it also offers some advantages such as a shorter wheelbase which keeps the turning diameter smaller and thus improves the maneuverability in tighter spaces ranging from rural unimproved mountain roads to urban parking spots that are often not so friendly to larger vehicles. Ground clearance and suspension travel might also be matters of concern for those who take off-road capabilities more seriously, even though some degree of components interchangeability makes it not so difficult to apply some upgrades originally meant for an SUV. However, since those Japanese vans that belong to the same class of the Toyota HiAce have an extremely utilitarian design still more focused on city and road operations, their wheel wells may be not so suitable to the oversized wheels and tyres frequently seen on SUVs like a Toyota Land Cruiser Prado. Actually, since a smaller tyre is usually more easily affordable, that would not really bother me.
SUVs being fancier than vans usually lead them to have a bigger footprint when we take in account their external lenght and width, but that doesn't reflect accurately in an improvement to interior space as it could be eventually supposed. A full-lenght bonnet/hood already takes too much of the platform lenght that could eventually serve to enhance the cargo and passenger capacity. Since midsize and full-size SUVs still rely more frequently on the traditional body-on-frame layout claimed to enhance the off-road capacities, with higher frame rails that would be supposed to be essential to overcome clearance issues for drivetrain and suspension components by setting the cabin floor to a higher position, internal height also becomes smaller and so goes the interior volume when a given external height limit is applied to both an SUV and a van. Even if we went to look some previous versions of the Toyota Hiace Regius/Grandia/Solemio that featured a semi-bonneted layout with the cockpit set a little further, the shorter cowl still leads to a greater use of space for passengers and to accomodate their luggage or even find some way to carry bulkier items or to fit a few more comfort features.

Another feature mostly neglected by able-bodied people is the usually wider door opening, as can be seen in the classic Volkswagen Kombi. Leading to either an easier loading and unloading of cargo or a more comfortable boarding and unboarding of passengers, it becomes particularly appreciable while dealing with disableds and the elderly. It's one of those features that some people accept to trade-off when they choose either a traditional SUV or a car-based "crossover" in order to not have a vehicle that looks like a cheap workhorse. It seems even crazier when, apart from the crossover SUV trend that led to a dismissal of vans and minivans as the people-mover of choice in many households, we remember all the urban cowboys who spend considerable amounts of money to get a pick-up truck with lots of fake chrome just to show off but would never even haul a sack of oats...

Friday, October 07, 2016

Why are ethanol and LPG not so suitable for the current generation of hybrid cars?

One question that has been raised for quite a long time is the suitability of hybrid cars such as the Toyota Prius to alternative fuels. Even though the average Joe might already regard the lower gasoline consumption as a step forward in the efficiency field and other aspects such as reducing the dependency on petroleum from war-torn and other politically-unstable zones or some environmental concerns, the capability to run on other fuels either perceived as "cleaner" or more affordable due to regional availability is becoming more relevant. Ethanol and liquid petroleum gas (LPG, also labeled Autogas in some countries) are well-proven as automotive fuels in a worldwide basis, but the current generation of gasoline-electric hybrid cars has some specific operating conditions that impose difficulties to use those fuels.
There had been some talks about a gasoline/ethanol flexfuel Prius since its official introduction to the Brazilian market in 2012 while it was still in the 3rd generation, but it never turned into a production model. Because of the ethanol fuel specifications in Brazil, with a 96% concentration on volume and about 4% residual water content, vaporizing is not so easy during cold starts and thus some cold starting aid is required when the fuel is used in a conventional port-injection engine such as the 2ZR-FXE fitted to the Prius. Older dedicated-ethanol and earlier flexfuel cars in Brazil required an auxiliary gasoline tank for the cold starts, nowadays mostly replaced by a thermostatically-controlled electric heating system for the fuel injection rail. Due to the intermittent operation of the internal-combustion engine in a hybrid vehicle on heavy urban traffic conditions, ethanol ends up not being so practical for all-year round operation. Unlike vehicles with a conventional non-hybrid driveline, which have benefitted from the downsizing trend that brought direct injection and turbocharging into the mainstream car market, the majority of hybrid cars keep the naturally-aspirated port-injection layout even though it's not due to cost concerns as often perceived. Since the prevalent sales argument for hybrids is a direct comparison with Diesel in the field of overall energy efficiency and emissions, resorting to this setup allows a lower intake flow temperature which leads to a lower nitrogen oxides (NOx) emission. Due to a small portion of the air/fuel mixture always returning to the intake manifold during the compression stroke because of an intentional delay in the intake valve phasing to emulate the Atkinson effect that turns the power stroke longer than the effective compression stroke, more latent vaporizing heat is absorbed from the subsequent intake charges, allowing the engine to run leaner while mitigating the risk of detonation/pre-ignition and not increasing the NOx emissions.
Therefore, a lower heat rejection can be expected from a hybrid car's engine. Eventually, such residual heat could be recovered and applied to vaporize the fuel through a heat-exchanger like it's usually done in a car converted to run on LPG, however it doesn't eliminate the need to use gasoline during cold starts until the engine temperature stabilizes. However, an intentional production of residual heat meant to help vaporizing some alternative fuel might not justify from an overall efficiency standpoint, while a short run before the idle shut-off might not lead the engine to a temperature suitable for neither ethanol nor LPG without having to resort once again to gasoline for a smooth restart. An upgrade from port-injection to direct injection could overcome this issue, but the air intake temperature and the compression heating would become higher enough to reflect into an undesirable increase of NOx emissions that would cut one of the most important competitive advantages held by the gasoline-electric hybrids against Diesel in times like these post-Dieselgate days.
Hybrid car owners looking for some gasoline replacement are actually not totally deprived of options. Despite of relying on a heavier and bulkier fuel system that leads to some compromise of the loading ability, compressed natural gas (CNG) is suitable to the intermittent operation of the engine and, since it's already stored in vapour phase at basically every ambient temperature, cold start won't be an issue. For those who seek renewability when choosing an alternative fuel, biomethane is the way to go. Since the chemical properties are identical to fossil natural gas, a transition to biomethane is easy as most of the pipeline and refuelling infrastructure won't require major changes.

Friday, September 16, 2016

NAMC YS-11 airframe on display

This was a NAMC YS-11 turboprop aircraft, roughly a Japanese copy of the Avro Hawker-Siddeley 748, formerly registered as PP-CTI and operated by Cruzeiro do Sul (Southern Cross), a former Brazilian regional airline that eventually merged with VARIG. It crash-landed due to poor visibility at the Navegantes airport on April 29, 1977. Navegantes is a city in the north shore of Santa Catarina state, on the way from Florianópolis to Curitiba.
Its landing gears were ripped out when it crashed, and therefore the aircraft was written off. Some of its parts were scavenged to be used as replacements for another of the same type that was also flown by Cruzeiro do Sul at that time, while the airframe was sold for scrap after some years abandoned in the airfield where the crash-landing occurred. Its right wing is reported to have been swapped into the PP-CTE, with the damaged wing being then attached to the PP-CTI when it became used as a pizza restaurant in Florianópolis from '86 to '93. Then, it was moved from Florianópolis to São José, and subsequently removed to its current location in Tijucas after a strong windblow almost lifted it in '95.
After some years still operating as a pizzaria, it became a churrascaria (Brazilian steakhouse). Nowadays, a snackbar was built right below it, with the old airframe becoming basically an ornament.

Most of its interior was removed, with the joysticks, rudder pedals and some levers (presumably engine throttle and propeller variable-pitch levers) to remember its days of glory.

Aside from Cruzeiro, other airline that operated this type in Brazil was VASP. Trying to look cool for the Japanese-Brazilian racial minority, VASP nicknamed it "Samurai". However, due to the crash records of the type in the country, it was also often called Kamikaze.

Monday, August 01, 2016

Decomissioned dedicated-ethanol Kombi ambulance turned into a donuts stand

This used to be a Brazilian Volkswagen Kombi that had been converted into an ambulance when it was still brand-new, then donated to the Santa Casa de Misericórdia (Holy House of Mercy) medical center in my hometown. The company that donated the Kombi was involved on illegal gambling scams and got bankrupt, and then it couldn't be registered for traffic on public roads, so it spent its 20 years only doing short runs from the hospitals of the Santa Casa's compound to its morgue.
The extra filler cap on the left side, set lower and further back comparing to the right-side one, was due to the small auxiliary tank that held gasoline for cold starts. Now it has no engine, so it wouldn't even justify being called a food-truck, but became quite attractive as a donuts stand.

Tuesday, July 12, 2016

Why did turbocharging and direct injection not become so widespread in the hybrid cars?

I'm not really so excited about hybrid cars, but there's something about them that really caught my attention recently. Since the main motivations that have driven some people toward the hybrids were expectations of an increased fuel-efficiency and lower emissions, why did some strategies on their way to become mainstream for non-hybrids such as turbocharging and direct injection not find their way into most of the hybrids out there? Maybe we could take a look at the Ford Fusion and its European equivalent, the Mondeo, since the engine options for them has so many distinct options even though not all of them but the gasoline-powered 2.0L Ecoboost seem to be available throughout all the markets where it's available, either badged as Fusion or Mondeo. There is a 3-cyl 1.0L Ecoboost catering mostly to Europe, a 4-cyl 1.5L Ecoboost which finds its way nearly everywhere but South America, the above-mentioned 2.0L Ecoboost, and a recently-introduced 2.7L V6 Ecoboost for North American markets, all of them gasoline-powered and fitted with turbocharger and direct injection. The only naturally-aspirated engines available are the 2.5L Duratec in gasoline and flexfuel gasoline/ethanol versions and the 2.0L Duratec in a gasoline-powered version fitted to the hybrid versions of the Fusion for the Americas and the Mondeo for Europe, both using a regular sequential, indirect, port-injection. Regarding the 2.5L which is actually meant as an entry-level engine in spite of its displacement that would make it liable to higher taxes in some markets and tollerates better some lower-grade fuels the port-injection is not so pointless at all, but when it comes to the hybrid wasn't it at least supposed to benefit from the new trends that have been improving the fuel-efficiency of non-hybrids? In real-world conditions it doesn't seem so accurate at all...
A pratical advantage of a turbocharged engine that would benefit people who use their vehicles in locations above the mean sea level is their lower performance loss at higher altitudes, whereas a naturally-aspirated hybrid wouldn't be initially supposed to provide some sort of altitude compensation. However, the combined output of both the internal-combustion engine and the electric motor is usually lower than the numerical sum of their individual power and torque figures, and can set automatically to a higher proportion of the electric power in such conditions while the gasoline-powered engine would still be able to drive the on-board generator even at a lower power due to the lower concentration of oxygen in the air at the lower pressure associated to a higher altitude. With the vehicle motion starting in electric mode by default, the driver is probably not going to even notice such a difference in performance regardless if it's on the beach or in the mountains. On the other hand, the port-injection in conjunction to the "Atkinson effect" provided by a longer intake valve timing can actually provide some mild enhancement to the density of the mass air flow and therefore increase its oxygen concentration. The intake valve timing duration extending into the beginning of the compression stroke, in order to make it effectively shorter than the power stroke, leaves some air/fuel mix to return to the intake manifold where the gasoline vapours are going to cool the charge air much like an intercooler would do in a turbocharged engine. There is also a reduction in the effective compression ratio which, by its way, decreases the aerodynamic heating inside the combustion chambers and therefore leads to a lower amount of Nitrogen Oxides (NOx) being generated. Since the gasoline also vapourizes more accurately than in a direct-injection which has the gasoline atomized into droplets but still in liquid phase, the surface area in contact with the oxygen in the air is increased, leading to a more complete combustion. Oily vapours admitted through the positive crankcase ventilation are also dilluted more effectively by the gasoline when it's port-injected instead of directly-injected, becoming also easier to burn accurately, which seems to match the "sustainability" approach surrouding the hybrid car market.

Friday, July 01, 2016

Kombi Lotação: a Brazilian-exclusive version with 6 front-hinged doors

It's not unusual for people who never went to Brazil to rely on misconceptions about local variants of the classic air-cooled Volkswagen models, such as the Transporter which is more known locally just as "Kombi" regardless of version, including the pick-ups and panel vans. Some even presume that this 6-door version known as "lotação" (Brazilian Portuguese for "jitney", "share-taxi" or "marshrutka") was the rule instead of an exception. Well, while having all the doors hinged upfront, and even some offside passenger doors, became a desirable feature for the share-taxi service, it would actually become unfavorable to load or unload bulky objects when the vehicle had the rear seat rows removed and was used to haul cargo. Therefore, the Kombi Lotação had quite a limited market share compared to the regular model fitted with the split curbside door.

The 6-door "lotação" trim lasted until early-'80s when the Brazilian Kombi had already undergone the facelift that led to the introduction of the single-piece windshield and started to become outfavored by municipal administrations that started pushing minibuses as the standard for the share-taxi service. A T2b "bay-window" Kombi Lotação, since is less sought after by collectors, might have become even rarer than a split-window by now. It was quite a surprise for me to spot this '77-'78 one in my neighborhood a few months ago, currently used by a construction contractor. It was quite derelict, missing some door handles and the running boards, but still working.

Wednesday, June 15, 2016

Polauto Pagus, an old Volkswagen-based kit-car from my hometown

Volkswagen-based kit-cars held some popularity in Brazil when imports were restricted from mid-'70s until '90, and the Polauto Pagus was an option for those who wanted a small double-cab pick-up truck. Made in Porto Alegre, the fiberglass body was attached to a Volkswagen Type-3, usually a Variant. It could initially sound a little pointless, especially considering that a T2 Transporter pick-up was already available with double-cab option and offered a bigger cargo area, but the Pagus and other similar models were aimed at those customers who were looking to stand out of the crowd when an imported car was nearly impossible to obtain in a legal way, and more leisure-oriented than a Transporter which was still regarded as a workhorse. Another factor that led it to reach some popularity back in the days was the lower licensing tax for pick-up trucks when José Sarney was the president of Brazil. The canopy over the load bay was an aftermarket accessory.