Diesel Parts & Services supplies large diesel engines for a range of industries and machinery. While we are not involved with the car market we couldn't help but be interested in some recent studies that show the efficiency of diesel engines in cars even in comparison to hybrid vehicles.
Despite what most people think, a new study has shown that driving a hybrid car is not always the most fuel efficient and environmentally friendly decision they could make.
Hybrid cars are advertised as the more efficient choice because they can use their battery power for gentle acceleration while gaining some of the energy back when they brake. However, they have a major flaw. Manufacturers of hybrid cars traditionally focus more on making the battery as efficient as possible. In doing so, they tend to neglect the engine which translates to a lesser fuel efficiency when the car is going long distances at a single speed. In fact, hybrid cars actually tend to use more petrol than traditional cars that use standard diesel or petrol engines when operating on highways or accelerating quickly.
The reason this is not more widely known is due to the nature of the official testing regimes which analyse cars' performances at much lower speeds. Therefore the hybrid, which has been designed to operate at the lower speeds with frequent stops and starts that characterise city driving consistently ranks higher than traditional diesel engines that are more designed for cruising at one speed or accelerating quickly.
Nick Molden of Emissions Analytics, the company that conducted the study, stated that "to some extent, the hybrids have had the aura that they are unquestionably a good thing, the general feel out there is that if you have a hybrid you are doing something that is unquestionably good for the planet and that’s not necessarily true, and it’s not necessarily good for your wallet.”
Experts from What Car? Magazine and Emissions Analytics performed “real-world” driving tests on either standard diesel cars and two popular petrol hybrids, which all used an engine ranging between 1.5 and 2.2 litres, which generates up to 150 brake horse power and used two-wheel drive.
Even when changes in battery charges were taken into account, they found that while the standard diesel engines outperformed the hybrid cars. The better performing car of the two hybrids, the Toyota Auris, delivered 58.7 miles per gallon on average, which was less than the Mazda 3, Skoda Octavia, Honda Civic, and Peugeot 308 and Mazda standard diesel models.
Under congested conditions, fuel economies lowered for both types of vehicles, 6-8.3 per cent for standard diesel engines and petrol engines respectively compared to 2.5 and 3.3 for petrol diesel hybrids. However, when tested on open roadways, standard diesel engines and petrol engines improved by 18.4 percent and 27.4 percent respectively. This is a drastic increase from the measly 1.1 and 8.5 per cent by hybrid engines. This information is supported by a large database made up of test previously conducted on more than 500 vehicles driving over a variety of road conditions and speeds.
Meanwhile, Mr. Molden counsels to match the vehicle to the job. "Hybrids may deliver good but not best-in-class fuel economy, but they are typically the cleanest, and if you are a light-footed, congested-town driver, they are ideal... but if you are a motorway cruiser, you are working mostly on the engine and running on a relatively inefficient petrol engine.”
So there you go. Even though we stock range of diesel engines are more heavy duty, the above studies show that the modern technology used to create these engines ensures high efficiency.