Fuel Types

There are multiple ways modern cars are fuelled and powered these days from fossil fuels, to electric and a mix of a couple. In the days of old you either had petrol and diesel and one was to go fast and the other was to save money on fuel - with the constant evolution in engine technology this is not the case anymore and each fuel type has their own little niche of benefits and drawbacks.

If you're shopping for car leasing offers and you're struggling to determine which is the best for you and your circumstances then this handy guide will help you out.

Petrol

Petroleum or otherwise known as gasoline or simply is an extremely flammable liquid which generates energy rapidly and powers the engine. It's been around since the late 19th century and has been refined over many decades to what it is today.

Petrol engines are the biggest selling as they tend to be cheaper to make and therefore cheaper to lease, they weigh a lot less than diesel engines and petrol itself is cheaper at the fuel station. This generally means that the same model of vehicle with a petrol engine is significantly cheaper than the same model with a diesel engine.

Petrol based engines tend to produce higher levels of co2s then diesel engines (as well as hybrids, hydrogen and electric) but the fumes themselves are less dangerous. Despite making great leaps in terms of economy and miles per gallon they still aren't as economical over long distances as diesels. That being said, the gap has been reduced somewhat with advanced technologies and the introduction of turbochargers to smaller petrol engines such as Ford's 1.0L EcoBoost engines.

Petrol engines are quick to warm up, do not suffer from the need of the diesel particulate filter and are ideal for short urban journeys even over hybrids as short journeys may not get the electric battery charged before the journey's over.

Benefits

  • Cheaper to buy from the onset
  • Weight significantly less than diesel engines
  • Quick to warm up and don’t need a long run to charge up or clear the DPF.
  • Less harmful fumes
  • Easier and cheaper to service
  • Quieter with a smoother drive
  • Able to still have decent torque through a turbocharger even on smaller engines

Drawbacks

  • Less miles per gallon than other fuel types
  • Less torque than diesel engines
  • Higher co2 emissions and therefore road fund license cost
  • Petrol engines without a turbocharger can be a chore to drive

Diesel

Diesel is a liquid fuel invented by Rudolf Diesel in 1892. His aim at the time was to create an alternate fuel and at one stage experimented with peanut oil. Modern diesel is a type of petrol which ignites without the use of a spark - instead, it is ignited under extreme pressure generated by the engine which results in the release of energy.

Diesel fuel powered engines have been known for a while to be more economical and produce less emissions as a result. This is achieved as more energy is released per litre of diesel than petrol, for example. However, diesel's emissions are more toxic than petrol and include greater amounts of nitrous oxide.

Diesel engines are typically known to have more torque (the feeling when you get taken back as the car pulls away) and power over petrol engines. Diesel engines typically have a turbocharger as the fuel itself is well suited from having a more compressed fuel to air ratio resulting in faster and greater energy release. Secondly, diesel releases energy quicker than petroleum and therefore is able to deliver the power quickly.

However, the greater power and nasty emissions come at a cost as these engines tend to be louder and produce more vibrations into the cabin. They are generally bigger and significantly heavier. These have been mitigated with clever engineering but the fact remains they are louder than petrol engines.

Benefits

  • Greater economy especially over long distances
  • Less co2 which results in lower VED
  • Well suited for towing and use in agriculture/construction industries

Drawbacks

  • Produce more harmful fumes
  • Uncertain future over availability and penalties
  • DPF filters are necessary and can be costly to maintain/replace
  • Cost more and are heavier than petrol engines
  • Noisy and not as smooth as petrols
  • Petrol Full Electric Hybrids (HEV)

The first publicly available and popular hybrid vehicle is the Toyota Prius followed closely by the Honda Insight. These two Japanese giants are the grandfathers of making hybrid vehicles accessible to the general public. These kinds of technologies have often been complicated and therefore costly which has made many manufacturers hesitant (at the time) to adopt ahead of fossil fuelled cars.. Thanks to the efforts of the Japanese market, this is no longer the case.

In modern times, more or less every major brand offers a hybrid even in their smallest urban designed city cars such is the rapid advancement behind this technology.

There are a few different types of hybrid petrol engines but the principle is still the same. Hybrid vehicles can use the petrol engine, the electric propulsion system or both to power the vehicle. Generally, the petrol engine is used to turn an electric generator and when fully charged can either help the petrol engine and thus reduce fuel usage or be able to take over completely.

Full hybrids have a battery and an electric motor which sits next to the petrol engine. These full hybrids can charge themselves just by moving along as well as storing kinetic energy from the wheels when its moving and breaking which goes back to the battery.

These hybrid engines enable the vehicle to emit less emissions (as the engine is used less or helped along) and offer massively improved miles per gallon. The petrol engine is still there to work the vehicle even if the hybrid system isn't ready but modern full hybrids are still viable even for urban living where short journeys are common.

Benefits

  • Greater economy as the petrol engine is under less stress
  • Reduced emissions
  • Ability to turn off the petrol engine and just use electric for short distances
  • Improved power over standard petrol engines
  • Tend to be automatics as standard

Drawbacks

  • Expensive technology
  • Not all hybrids perform at a similar level

Plug-in Hybrids (PHEV)

Plug-in hybrids are similar to full hybrids except the battery can be powered by literally plugging the vehicle in to an electric source which charges the battery for use. Opting for a plug-in option can reduce costs further as it relies less on the onboard engine charging the electric motor. However, a new cost is introduced in the form of an increased electricity bill.

The concept of a plug in hybrid is now new and was explored in 1969 but with little interest for many decades, possibly due to the available technology not quite being there. A revival began in 2003 with the Renault Elect road but was downplayed in favour of the rise of full hybrids.

As of 2017 there are around 40 different models of plug in hybrids with more and more being added each year. A particular success story for plug in hybrids is the Mitsubishi Outlander which is the best selling PHEV to date, worldwide.

The PHEV is built on more or less the same platform as a conventional hybrid but offers a slight advantage in terms of economy and emissions in exchange for the inconvenience of plugging it in. However, plug in ports are becoming more and more common and often you can charge your vehicle while at work, doing your shopping or visiting the gym.

Benefits

  • Greater fuel economy than full hybrids
  • Reduced emissions
  • Less strain on the engine to charge up
  • Larger and more powerful battery
  • May have access to tax incentives

Drawbacks

  • More expensive
  • Reduced electric range
  • Must be charged manually
  • Must stop to recharge during a long journey if you want the use of the electric motor

Electric

Electric-powered vehicles have been heralded as the future of automobiles now that the technology has reached the point where they are able to perform at a high level and be affordable. However, the idea of a vehicle being powered just by electricity is not a new idea at all with the first EV being made in the mid 19th century. Little was done for decades as the technology and materials available couldn't make them viable and the demand wasn't enough to sell.

The last few decades have proven instrumental in the evolution of the EVs we see today. With events such as global warming, the rise of fuel prices and the fear of peak oil have put manufacturers and various R&D departments around the world on alert that a change is needed and is coming.

A major attempt at a mainstream EV came circa 2003 with EVs coming from Chrysler, Ford, GM, Honda, and Toyota. When General Motors produced the EV1 GM had to discontinue due to pressure from the Government as well as the Automotive and oil industries working together to make EVs undesirable. Clearly, the tables were turning and it was only a matter of time before the cries for EVs were not able to be silenced.

By 2030, it is estimated that 33% of new cars sold will be electric vehicles which is a giant leap in progress from the days of being silenced. Quite an achievement.

Electric vehicles have an electric motor powered by a rechargeable lithium-ion battery. The motor converts electrical energy into mechanical energy which then turns the wheels. There are no moving parts and no fuel being burned which results in zero emissions. Not only that, electrical power results in instant torque which can make comparable EVs more powerful than their fossil-fuelled counterparts.

The biggest challenge with EVs is the range before the battery is depleted yet this is the area which is seeing the most improvements. The Tesla Model S Long Range has a range which almost matches many petrol-fuelled cars (390 miles) whilst the more mainstream vehicle e-Golf has a range of 123. But, charging points are becoming more and more common and cheaper to recharge than it is to refuel petrol or diesel.

Electric vehicles can have a higher entry cost than fossil-fuelled vehicles and hybrids, however through their use over years the extra cost may return in the form of savings from fuel. EVs also have a much lower carbon footprint and with enough use around the globe the air quality and reliance on fossil fuels should come down.

Benefits

  • Zero emissions
  • Instant torque
  • No longer need to refuel at petrol stations
  • Access to cutting edge technology

Drawbacks

  • Technology can become out of date quickly
  • Expensive to repair
  • Expensive entry costs

Hydrogen

Hydrogen-powered vehicles are not mainstream and are a competitor to EVs insomuch that their primary goal is to become greener and less reliant on fossil fuels. However, the whole point of hydrogen vehicles is to take hydrogen and convert it to electricity which powers the car with many critics feeling EVs do that with one less step.

However, hydrogen-powered vehicles are still a great step forward from the shackles of petrol and diesel. There are no moving parts in the fuel cell which results in greater efficiency and reliability - nothing moving means nothing can break!

But, the biggest criticism of hydrogen production is that a lot of it requires fossil fuels to make the gains from having less emissions from the car a moot point. Lastly, hydrogen is a dangerous substance and flammable which concerns a lot of people despite the safety assurance from manufacturers.

Benefits

  • Zero emissions
  • Advanced technology

Drawbacks

  • Hydrogen fuelled cars are expensive
  • Limited places to replenish the fuel cell
  • Not as supported as EVs