I am part of Scania’s mission to strengthen its leadership in change to a transport system cleaner and greener; are committed to introducing fuels in our country that help to reduce the CO2 footprint and by using fuels that are present in the country.
For example, the Griffin brand strongly promotes gas technology for both trucks and city buses. Already in the year 2020, it presented its G410 truck to continue with the whole range later and get into city buses later. Now Scania is working on medium-haul buses that have seen significant growth in recent times and they estimate the brand will continue on that path.
This type of medium-haul bus is not only more profitable, more versatile for certain routes where a long-distance bus is not necessary, but also easier to drive, with better maneuverability and fewer axles; works much better than a double deck.
That’s why the Swedish brand, together with the body of Saldivia, built the K320 IB Green Efficiency CNG intercity bus that we could see in detail. This bus will be available in three types of configurations: 46 seats with bar or bathroom; 48 seats with bathroom and 53 seats.
We spoke to Julian Rosso who works as Sales Engineering Manager for Scania Argentina, who gave us all the features of this CNG bus.
Rosso explains that aesthetically at first glance the CNG bus has practically no differences, we can only see a ventilation in the first part of the hold where the gas pipes are located and in the tires that are super wide to compensate for the extra weight that they provide CNG piping; in order not to lose the payload and to be able to carry the same number of passengers.
We may ask why a CNG bus? Firstly, because it has a significant impact from an environmental point of view, because when used with compressed gas – the main gas we have in the house – it can reduce CO2 emissions by up to 20%, about 95% of nitrous oxide emissions and almost zero emissions. particulate matter. On the other hand, it has a much improved comfort because it makes almost no noise and does not vibrate like a diesel.
With regard to this point, the representative of Scania limited «In this type of vehicle, given its size, a small vibration spreads very easily and the internal noise becomes large. In addition, the older a diesel is, it usually gets worse and in this case the CNG vehicle makes practically no noise or has engine vibrations because it is very smooth, which improves the interior comfort for the passengers. «On the other hand, from an economic point of view there is no sustainability if there is no economic sustainability, as this bus is much more profitable“and I add”operating costs drop remarkably, it is usually between 35 and 40% savings in fuel consumption«.
The bus is equipped with a Scania DC09 5-cylinder in-line engine -approved according to Euro VI standards-, in contrast to diesel it works with the Otto cycle. It has a displacement of 9.3 liters and develops an output of 320 hp at 1,900 rpm, with a torque of 1,500 Nm between 1,100 and 1,400 rpm. The gearbox is in turn the well-known 12-speed automated Opticruise and, in addition to the engine brake, the Retarder with a braking power of 670 CV.
Speaking of the gas equipment, it has 6 tubes of 150 liters each, which can load 215 m3 of gas, allowing it to cover 600 kilometers of autonomy in normal use. The charging peak is the same as that of trucks, called NGV1, which is slightly larger than the traditional peak of cars. Scania has an adapter that is also available as a spare part. In the case of charging with a traditional dispenser and spout, it takes about 30 minutes to fully charge the 6 tubes; Now if it is done by means of high flow dispensers with a thick spout, the loading will take no more than 5 minutes.
This bus can also be fed with biogas without modifications to the impeller, as it is the same gas as natural gas but of organic origin. With this type of fuel, emissions drop by up to 90%, with a very significant impact, which is close to zero.
From the brand they expect that more tubes can be added to have more autonomy, although it is necessary to homologate it because the structure of the bus has to be adapted, logically at the expense of storage space.
On the difference in power and torque related to the diesel, the head of Engineering replied: «We are very evenly in a 320 hp CNG engine against 310 hp diesel, in terms of power there is only 10 hp and in torque the CNG has slightly less but keeps the same type of curve as the Scania engines. The difference for a bus with these characteristics is insignificant and in this case there is an advantage that it has a 12-speed gearbox versus an 8-speed gearbox, which allows to stagger the changes and thus obtain smoother accelerations.«.
When we talk about the elements it shares with the diesel engine, we only mention the crankshaft and block and a large part of the peripherals – alternator, water pump, etc. – . Then they change the pistons, the design of the cylinder head, the valve seats, the installation of spark plugs for the ignition, the intake and exhaust manifold and the turbo because of a matter of temperature because it has a different functionality of the cycle and management of the engine changes significantly. On the other hand, not only the hardware but also the software has been worked on to make it comparable to the performance of a traditional diesel.
When Rosso was consulted on the work on valves given the complete combustion of the gas, he stated: «The seat material has been changed and the valve design has been changed to allow for a wider contact angle and greater cooling to avoid burning the valve seats.»
The CNG tubes are manufactured in Argentina, as well as the body, with this bus being an important part of the national integration, with the chassis and engine being imported elements. These tubes are fitted during the body of the vehicle by a Scania approved and verified supplier.
Looking at the bus driver we see the fuel line going to a control panel and from there is a hose going to the injection rail which is very accessible for any maintenance job with no parts to disassemble. On the other side, the 6 tubes are fed into a main tube and a vent comes out to safely discharge any gas overload.
Regarding the maintenance of this type of motorization related to a diesel, the technical representative of the Griffin brand added: «service times compared to a diesel are slightly longer for two reasons: it has spark plugs and they need to be changed at the same time as the filter and oil, and the oil is slightly more expensive as it is specific to this type of engine. It requires no additional maintenance other than the annual checkup to revalidate the CNG wafer, checking and making an electronic diagnosis to ensure all components are not leaking through a test protocol«. On the other hand, he stated that the durability of the CNG impeller is at least equal to that of a diesel.
This is the first with the bodywork of the Saldivia Aries model; Scania’s idea is to expand the product portfolio and have more bodies. The brand will include it in its fleet of Demo Trucks for testing by future customers, but the bodywork homologation must first be completed.
To give us an idea of the difference in value compared to a diesel, this CNG bus has a 30% higher price.
After getting to know the new medium-haul CNG bus in detail, we didn’t get in it and drove a few laps around the circuit that counts FADEEAC in Escobar. Like the trucks of the brand, the seat is adjustable in length and height, as is the steering wheel.
We put the Opticruise gearbox in position D, released the brake and the Scania bus started to drive very smoothly. We accelerated it and the marches started to rise, but without realizing it. The 12-speed gearbox is staggered so that it resembles a continuously variable type gearbox that cars have. On the other hand, before cornering or taking a round trip, we use the five-point retarder to slow down – a genius invention that I invite you to know how it works HERE –
As the conclusion of our short test, we can say that there is no noise or vibration, so not only the driver but all passengers will enjoy a pleasant journey. And a little more, with 35% lower operating costs and environmentally friendly through the emission of cleaner exhaust gases.