Hydrogen as a fuel: a distant dream

For a long time, alternative fuels have been researched, and one of the most prominent is the Hydrogen. Altough its combustion process is reported to be the cleanest one due to the emissions restricted to vaporized water and being the most abundant chemical element in the Universe, Hydrogen is also the most reactive, then it must be extracted from chemical compounds like water or methane, that is currently the most common Hydrogen source besides its usage as a fuel (usually labeled as CNG - compressed natural gas - or NGV - natural gas for vehicles) widely accepted commercially in India, Pakistan, Argentina, Italy and Brazil.

Unlike water, which electrolysis releases only Oxygen, methane processing releases carbon dioxide, the same compound intended to be cut away from tailpipe emissions in hydrogen-powered vehicles. Considering that a biggest chunk of all the methane turned into Hydrogen is coming from fossil reserves, turns its usage as a fuel pointless in an environmental aspect, while other options as the biodiesel and even the ethanol are more effective in this matter. Also, due to all the energy spent to process the methane and subsequently store the Hydrogen in a safe way, it does worth more to use the methane itself as a fuel.

One of the ways intended to make use of Hydrogen is thru the fuel-cells (also often quoted as combustion-cells), promoting a combustion that releases an electric current used to power an electric-drive motor. First experiences in a fuel-cell vehicle were attempted by General Motors in 1966 in a prototype badged as Electrovan and based in the ChevyVan available at the time that was chosen over a regular sedan due to the enormous size and the extra weight of the Hydrogen-powered setup. Currently the systems evolved to a point that it can be bolted into a smaller vehicle such as the Opel Zafira and the Chevrolet Equinox without too many interferences in the passenger space and cargo capacity. The first manufacturer to release a fuel-cell vehicle to the general public was Honda with the FCX Clarity in 2008, but the availability is extremely limited to some areas in California and Japan due to the absence of Hydrogen refuelling stations enough to a worldwide offer.

Another way to use Hydrogen is into internal-combustion engines, with highlights to BMW and Mazda, since it also allows an easier usage of more traditional fuels such as gasoline and ethanol. Hydrogen, however, has a lower energy density and the on-board storage is quite problematic. Usually, a carbon-fibre storage cylinder is certified to 900bar, and while the most usual CNG setups have a 200bar working pressure Hydrogen is kept at 700bar, with a smaller safety margin. Also, beyond the safety valves required, due to the size of a Hydrogen atom it easily escapes from micro-fissures in the tank walls, requiring the vehicle to be stored in places with a good air circulation to avoid an explosive atmosphere to be generated around the parked vehicle, turning it into a less attractive option not just in the economic viability matter but also due to the safety.

So, despite the daydreams in late Twentieth Century years and early 2000s, Hydrogen kept a distant dream to the motor world in general...

Engine placement in buses: many aspects involved in the final decision

All around the world, buses perform an important role in the economical and social aspects. Many differences can be seen among these vehicles, and the engine placement is often quoted as the most notable one.

In some countries like Brazil, urban transit buses with front-mounted engine are still very popular due to the low purchase cost, simple technical features and interchangeable parts with trucks. No wonder these vehicles are often quoted as a bare truck frame with a bus body, also considering that non-adjustable all-metallic suspensions, usually with the same leaf springs setup from trucks, are still prevalent on front-engine buses.

They're also usually qouted as "more rugged", then better to cope with hilly terrain and poorly-paved (or even unpaved) roads still easily found in Brazilian suburbs and countryside areas. However, for inter-urban commuting operations or long-distance road service, rear-engined buses have become more usual, not just because they lead to larger and fully pass-thru luggage compartments but also due to the higher comfort since there is less noise inside the vehicle at all and less heat in the cockpit.

Also, due to the weight distribution more concentrated around the traction axle even while the vehicle is unloaded, it ends up not so bad to face some rough terrain.

Another advantage from the rear-engine setup is the allowance of a fully-plain floor without any step, leading to an easier, safer and faster accessibility to disabled people in urban transit buses, due to the lesser space required on the floorpan to get clearance from the driveshaft and the transmission.

However, since low-floor frames are often qouted as unsuitable for some routes, even among the rear-engined buses it's still easy to find vehicles with a regular floor height and steps, leading to the need of a hydraulic elevator to get accessibility for wheelchair users, like any average front-engined bus.

Another setup that is worth to quote but is not so usual is the mid-mounted engine, mainly promoted by Volvo with the B58, B10M, B12M and B340M. It had a good acclaim from the coach segment but is more remembered due to the urban articulated buses that have become a trend due to the BRT systems.

Nowadays the mid-engined Volvo frames are restricted to the articulated buses, currently facing only rear-engined ones as opponents. However, since it's harder to get a low-floor without any sacrifice to the passenger capacity, rear engine ends up as a more profitable option to the fleet manager.

Also, despite one myth still prevalent about rear-engined buses being related to some difficult to perform the PMS, its larger engine bay eases the access to mechanical and electric components, and then the services can be performed quickly, leaving the vehicle ready to hit the road sooner.

It's also often pointed as easier to fit some comfort features like HVAC and self-levelling air suspension in a rear-engined vehicle due to the space-saving around the frame, leading to a "premium" aura for them, leading to a misconception that it shouldn't be introduced to some routes in lower-income neighborhoods to retain the "prestige" image of the rear-engined buses over the front-engined ones.

But the initial lower purchase cost goes away considering that a rear-engined vehicle can be more profitable to operate. Usually, a rear-engined bus is lighter due to the lower frame rails due to the lesser clearance required from the driveline (however retaining the tortion strenght), shorter driveshaft and exhaust pipe, leading to fuel-savings.

It's also more usual for the rear-engined bus frames to be fitted with automatic transmissions, while the higher fuel consumption reported from the older designs nowadays is getting closer to the fuel-efficiency of the manual transmissions, getting wider maintenance intervals. Also, the hydraulic torque converter that provides the coupling between engine and transmission suffers less damages than a regular clutch in routes with a lot of start-and-stop, what is very desired to face the heavy traffic in major cities.

The already-proven ruggedness is still favorable to the front-engine setup, but the rear-engine has becoming increasingly popular in a wider range of applications, not just in the urban transit segment...

RHD to LHD conversion: is it really justifiable under a safety view?

For many reasons, such as colonial heritage, national sovereignty, cross-borders driving safety or even economical reasons, left-hand traffic is still enforced in some countries, altough right-hand traffic is currently more usual.

However, this doesn't prevent second-hand Japanese right-hand drive vehicles, intended for left-hand traffic, to be popular even in right-hand traffic countries such as the Philippines, Paraguay, Bolivia and Chile, altough RHD to LHD conversions being mandatory for the vehicles to become street-legal. Main reason for that is the visibility while passing by other drivers, preventing head-on collisions.

Other right-hand traffic countries that allow the Japanese RHD used cars, such as North Korea, Russia and the United States, don't require the conversions. In the United States there are even some locally-made special-purpose RHD vehicles, such as parcel-delivery vans allowing the driver to get out of the vehicle already on the curb side. Canada had an RHD ban held in Quebec despite its increased comfort for rural mail carriers who could easily perform their duty without getting outside the vehicle in the cold weather. This led up to some RHD vehicles to be converted to LHD in the Philippines before the arrival in Canada.

I have already seen personally some Japanese vehicles converted from RHD to LHD, and despite the improvements in high-end setups there are still some cheaper backyard workarounds that end up as a threat to the safety, such as the use of motorcycle transmission chains and sprockets to link a simply cut-away steering collumn to the remaining right-side steering box instead of reverse the assymetrical steering links and a proper relocation of the steering box and the power steering hydraulic pump (when applicable) for safety and weight-saving reasons.

Even in a good-quality conversion, often the relocated steering collumn can lead to clearance issues with peripherals at the engine bay like the HVAC compressor, alternator and brake booster (that also are usually relocated) or with turbochargers when there is no LHD provision in the vehicle's original design, leading to a messy appearance inside the engine bay if the accessories mounting brackets and the exhaust manifold (including the turbo housing) are not properly rebuilt to meet LHD specifications.

Nowadays, due to the extensive use of global platforms by the automakers for cost-cutting, this problem is not so usual anymore, and interchangeable parts from official-market models can be easily found to increase the factory-like finishing, altough increasing the cost.

But we must consider the main reason to the RHD grey-imports popularity in some markets like Paraguay and the Philippines is the price tag, and even after the LHD conversion it's usually lower than the price of a factory-fitted LHD vehicle. Often, due to low budget, the interior trim is quite neglected and some driving interfaces such as the automatic transmission shifter knob and electric functions controls are not reversed to ease the operation, despite all the complexity of the mechanical and structural changes involved with the relocation of the steering setup and pedal assemblies.

Afterall, I'm not so favorable to the RHD to LHD conversions since there are nowadays some different options to overcome the visibility issues that are not just cheaper but also avoid a badly-performed conversion. The use of an auxiliary camera mounted either at the top of the left A-pillar, in a similar scheme to the reverse-view cameras currently very popular as an aftermarket mod (and even as a factory option for some models) is an easier and cost-effective way to solve that problem, plus not taking the vehicle's safety and structural integrity at risk.

Since some newer audio systems are fitted with a multi-function screen, sometimes integrated with other electronics of the vehicle, this could ease the adaptation of this visibility-enhancement setup, altough I would prefer either a dashboard-mounted screen or integrated to the inner rearview mirror.

The same functionality has been adapted into some LHD Brazilian-made Volkswagen Kombi vans that were exported to Japanese and British collectors in early 2000's with a small camera top-mounted at the right side of the vehicle for a safer drive in left-hand traffic. It's also an usual add-on to large American LHD vehicles in Japan.

Considering another detail that can get unnoticed but makes a huge difference, the windshield wipers mounting position and sweeping pattern, often remaining unchanged in the converted vehicles and then more favorable to RHD visibility, it makes even more sense to remain RHD. It's also not so unusual for the SRS-Airbag to be disabled altough remaining present, giving a false safety sensation to the unsuspicious driver of an LHD-converted car.

So, the safety argument favorable to the conversions goes over...

Ancient cars: a real threat to the environment?

 Old cars, like the Volkswagen Karmann-Ghia, are capable to awake passions even after decades out of the production lines. Not just due to the design cues, the old-school rides also delight enthusiasts all around the world. However, emission and safety laws often make them be seen just as a piece of junk despite all the historic value and even some technical advantages over current options on the market...

The Karmann-Ghia itself, for example, doesn't require cooling fluid for its rear-mounted air-cooled engine, avoiding potential risks of an incorrect disposal of it. Also, since it's carburettor-fed is easier to perform emergency repairs at the roadside while in a modern average plastic ball car with electronic fuel injection a computer is often demanded to be connected to the engine.

Despite all that environmental speech claiming newer vehicles as "more fuel-efficient than old beaters", it does worth to remember that some old engines such as the GM "Iron Duke" 4-banger with a 2-bbl carburettor can make an old Chevrolet Opala from Brazil or a South-African Chevrolet Ranger get a mileage close to new models in a comparable size, often with an engine displacement above its 2.5L.

And since its RPM range is not so broad, the torque distribution at a lower revving is already well modulated even without modern tricks like the variable valve timing.

A carburettor also has a smaller impact in the environment when disposed than a complete EFI setup with all its wiring and electronic modules, being easier to recycle with low technical resources.

And even repairs or preventive maintenance are simpler, cheaper and can even be performed at home with simple tools. No wonder the Toyota Corolla still relied on carburettors for its entry-level versions in the Philippines until late 90's, for example...

Another trend that is now outdated in the automotive market are the 2-stroke engines, that are still remembered in models like the DKW F-91, known in Brazil as DKW-Vemag Belcar.

Due to the old 2-stroke oils from its time, often the engine is reported to release a dark-colored smoke, but this issue has been addressed by current synthetic oils that have becoming popular among off-road motorcycle riders or even the vegetable-based ones used in kart racing. Also, since the oil is burnt alongside the fuel, it avoids unproper disposal of old motor oil that can lead to water and soil contamination...

Another point of interest is the ability to run on alternative fuels in older vehicles: while the electronic engine management features were already available when models like the Chevrolet Lumina APV/Pontiac Trans Sport/Oldsmobile Silhouette started to hit the American market as FFV's (FlexFuel Vehicle) in 1992, the Ford Model T had a special carburettor with a variable diffuser since 1908.

OK, the manual ignition advance control helped to deal with the flame propagation speed issue using different fuels like ethanol, gasoline or kerosene. Even gaseous fuels such as CNG/biomethane could be used without all those electronic auxiliary modules from aftermarket conversion kits to fool the electronic control management in modern engines...

 As far as ethanol goes, it does worth to remember again the Volkswagen air-cooled engine: from early 80's until 2005, it had some dedicated-ethanol versions available in the Brazilian market. An used cars dealer from Pelotas city, near the Uruguayan border, once told me that he had a dedicated-ethanol Beetle, but due to an innacurate thermostatically-controlled airflow restriction device around its heads and cooling fan he often used gasoline in the winter to get the idling more stable. But, despite some beliefs that an air-cooled engine is harder to convert to run on alternative fuels due to the less accurate temperature control, it's not impossible.

Other engines often portrayed as a danger to the environment are the diesels, most notably the older ones with an all-mechanical injection setup. The particulate matter emissions issue has been addressed in newer vehicles with the electronic injection management and particulate filters, but actually even an old diesel with a correct tune at its injection pump won't generate an outrageous amount of soot...

It's also not so unusual for an older diesel-powered car to have a higher fuel-efficiency than a comparable gasoline-electric hybrid. Also, the compression ignition works better with liquid alternative fuels such as ethanol and biodiesel, while the inability to operate with gaseous fuels that require a spark ignition is not really so intense if we consider the trend in the current hybrids that is a workaround on the camshaft to hold the intake valve timing for a longer period to simulate a power stroke longer than the compression stroke, like happens in an Atkinson-cycle engine.

And the traction batteries of a hybrid are filled with some dangerous chemical compounds...

It does also worth to remember that some older vehicles demanded a smaller amount of raw materials than its recent counterparts to be made of, such as the 1st-gen Volkswagen Transporter, known in Brazil as Kombi and remaining on production. Its external size is actually closer to the minivans, but it can often face some modern opponents in an upper size class without too many disadvantages...

 Another thing to consider is the comfort: some older models like the classic Jaguar XJ-series still have an outstanding setup that actually doesn't owe too much to its newer counterparts such as the smaller Jaguar XF.

Okay, some newer amenities and gadgets are cool, but are'em really necessary in a car??? Actually no...

So, despite some different opinions, an old beater can even have a lower environmental impact than a brand-new vehicle...