A diesel engine’s intrinsic disadvantage is that it struggles to get enough air into the combustion chamber, and turbocharging can greatly assist in this regard.
Instead of increasing combustion pressures, the goal with commercial diesel engines is to improve airflow to the engine (as combustion pressures are already high). This means that the overall ‘boost’ delivered by the turbo on commercial diesel engines is often fairly low around 5-8 psi.*
In reality, this means that diesel turbochargers are often larger than their gasoline equivalents, with a huge turbine section capable of handling both the enormous volume of exhaust gases and the requirement for sufficient air intake to keep the cylinders supplied.
*Note: Due to technological advancements, turbochargers in some current passenger diesel engines (as well as some used in smaller commercial vehicles) now operate at higher boost pressures. Look for a blog post about modern advances in diesel turbocharging in the near future.
The purpose of adding a turbo to a petrol engine is to improve engine power, hence the goal is to raise the pressures inside the combustion chamber. This means that petrol turbochargers are often smaller and intended to run at much higher RPMs, resulting in a bigger increase in pressure without boosting airflow significantly.
Furthermore, because petrol engines must function over a significantly larger range of RPMs, petrol turbochargers must come up to speed (‘spool up’) faster than diesel turbochargers.
Finally, with petrol engines, the higher RPM of both the engine and the turbocharger generates a lot of heat, which must be carefully managed and many turbos rely on the back pressure of these hot gasses to improve efficiency and operation.
Is there a turbocharger on a petrol engine?
Since 1962, turbochargers have been employed on a variety of petrol engines to increase power or torque production for a given engine displacement.
The majority of turbocharged petrol engines use a single turbocharger, but twin turbocharger setups are also common.
In the 1970s and 1980s, turbochargers were employed in a variety of motorsport disciplines. Turbocharging has made a comeback in numerous motor racing categories, including Formula One and the World Rally Championship, since the mid-2010s.
Several motorcycles with turbocharged engines were produced in the late 1970s and early 1980s.
Is a turbocharged gasoline engine better?
Turbo engines are more efficient in general due to their reduced capacity. The fuel economy, on the other hand, is determined by your driving style. You should expect decent fuel economy if you drive gently on the throttle, but if you drive forcefully, a turbo engine may waste more fuel.
Yes, in terms of performance and efficiency, a turbocharged engine outperforms a standard engine. A turbo engine with a lesser capacity can provide the same amount of power as a NA engine with a bigger capacity.
Yes, a car with a turbo engine is suitable for city driving. A turbocharged engine creates more torque lower in the rev range and increases low-end performance, which is necessary for driving on crowded roadways.
Turbochargers are employed in diesel engines for a variety of reasons.
Turbocharging a diesel engine can considerably boost its power output, bringing the peak power-to-weight ratio closer to that of a comparable petrol engine.
Over the last decade, improvements in power, fuel efficiency, and noise, vibration, and harshness in both small- and large-capacity turbodiesels have sparked broad adoption in certain countries, most notably in Europe, where they account for more than half of new car registrations (as of 2014). Turbodiesels are more adaptable to automotive applications than normally aspirated Diesel engines. Turbodiesels can be constructed to have a more acceptable torque dispersion across their speed range, or, if developed for commercial usage, to improve torque output at a certain speed, depending on the application. Naturally aspirated Diesels nearly always produce less power than a petrol engine of comparable capacity, while also requiring stronger (and hence heavier) internal components such as pistons and crankshaft to handle the higher pressures of the Diesel engine’s significantly higher compression ratio. Because of these reasons, normally aspirated Diesel engines have a low power-to-weight ratio. Turbochargers are small and light, yet they can provide significant gains in power, torque, and efficiency. A turbocharger can raise a diesel engine’s power-to-weight ratio to the same level as an equivalent petrol engine, making turbodiesels appealing for automotive use, where manufacturers strive for consistent power outputs and handling characteristics across their entire range, regardless of the power unit used.
Is there turbo lag in petrol cars?
Because turbo petrol automobiles are a relatively new technology, turbo lag is usually associated with them. The turbine and compressor are positioned on the same shaft in the turbocharger. As a result, movement of one implies movement of the other. The exhaust gases from the engine drive the turbine side of the turbocharger. The turbine rotates due to the mass flow of gases. As a result, the compressor turns, sucking in additional air into the engine. If there is more air inside the engine, more fuel can be injected, and more power can be created. A turbocharger operates on the same basis. In India, we are seeing an increase in turbo petrol cars, which are designed to provide the same degree of torque as diesel cars but producing less pollution.
Is it better to have a turbo petrol engine or a turbo diesel engine?
To withstand the high combustion pressures produced by diesel fuel, diesel engines are typically larger and stronger than their petrol counterparts.
However, because of their larger size, diesel engines have a harder time running at higher revs per minute (RPM), which means they have a harder time drawing in enough air to generate more power. If a corporation wishes to increase the power output of a diesel engine, turbochargers come in handy since they make the work of getting more air into the engine much easier.
Another distinction to note is that turbochargers in diesel engines often provide just a modest gain in power, especially when compared to turbochargers in gasoline engines. The installation of a turbocharger on a diesel usually has more to do with dependability and reliability than with increasing power output.
A turbocharger on a petrol engine is more concerned with increasing power. In the end, petrol turbochargers are smaller and built to run at significantly greater RPMs than diesel turbochargers.
Because turbochargers in petrol engines must operate at significantly higher RPM bands, they must be able to accelerate more quickly than their diesel equivalents. Turbo petrol engines generate more heat than diesel engines because they must run at higher revs, necessitating the usage of a cooling system.
Is gasoline preferable to diesel?
You may pay less per litre for petrol than for diesel, but you may wind up consuming more of it. This is especially true for longer travels at higher average speeds, which is when diesel engines are most efficient.
It probably won’t register if your only long car journey is the annual 200-mile round trip to see relatives but if long motorway journeys are a regular feature in your life you’ll probably spend a lot more on fuel with a petrol car.
CO2 is one of the principal “greenhouse gases” associated to climate change, and petrol cars emit more CO2 from their exhaust pipes than diesel cars.
Because of the higher CO2 output, petrol automobiles registered before April 2017 are likely to have higher tax rates. Prior to that date, CO2 emissions were used to compute a car’s annual road fund license (often known as ‘road tax’). This means that cars with fewer CO2 emissions, such as diesels and hybrids, are less expensive to tax.
Is it true that turbo reduces mileage?
You’re not alone if you’ve ever observed that your automobile consumes more gas than its official rating says. Especially if you have a turbocharged vehicle.
Turbochargers are the latest automotive engineering darlings. Car manufacturers are increasingly turning to small-displacement, turbocharged engines to meet government-mandated fuel efficiency advances. It’s something that almost everyone does. Instead of the usual V-8, Ford provides a turbocharged V-6 in its F-150 pickup. The engine in Porsche’s classic 911 sports vehicle has been shrunk from 3.8 to 3.0 litres, but it has been made more powerful by the addition of two turbochargers.
These new power plants, in theory, offer the best of both worlds, producing at least as much power as a larger engine while using less gasoline. That is, at least, the theory. The actual world is a different story. Let’s take a look at an example from recently.
I was expecting some impressive fuel economy stats when I picked up the Ford Focus One-Litre Ecoboost for a long test drive. The little Focus appears to be a serious efficiency challenger on paper, with a six-speed transmission, start-stop technology, and a one-litre three-cylinder engine with direct fuel injection, a variable-pressure oil pump, and a turbocharger.
The One-Liter Ecoboost Focus gets 30 mpg in the city (7.8 L/100 km) and 42 on the highway (5.6 L/100 km) according to the EPA. Those are excellent figures. My results, on the other hand, were not even close.
Around town, the One-Liter Ecoboost burned 11 to 12.5 L/100 km on a regular basis, which isn’t much better than the 2.5-liter, all-wheel-drive Subaru Outback I tested last winter. On the highway, the Ecoboost’s usage dropped to around 8 L/100 km, which wasn’t bad but wasn’t great either. These were poor results for a three-cylinder, one-litre automobile that was designed to enhance fuel efficiency.
I wasn’t surprised at all. Turbocharged cars, as I’ve found from years of testing, often have significantly lower fuel economy than their official figures suggest. My findings are consistent with those of other tests.
According to Consumer Reports, smaller turbocharged engines often get worse gas mileage than larger engines without turbochargers. Ecoboost Ford Fusions with turbocharged four-cylinder engines burnt more gas in their tests than their larger, naturally-aspirated rivals.
When CR compared a turbocharged 2.0-litre Ecoboost Ford Escape against a Toyota RAV4 with a 3.5-litre non-turbo V-6, both vehicles returned 22 miles per gallon in the United States. However, the Ford was 1.5 seconds slower in a zero to 100 km/h acceleration test.
Green Car Reports also conducted a series of tests to see if smaller, turbocharged engines were truly the greatest option for getting decent gas mileage. “With the latest generation of compact turbocharged engines replacing larger variations, real-world gas mileage increase is nowhere like that of the on-paper advantage in official economy,” they conclude.
The real-world results that turbocharged cars produce appear to violate engineering theory. The premise behind turbocharging is sound: you recapture thermal energy that would otherwise be lost out the exhaust pipe by using exhaust gas to drive a turbine that compresses the new air entering into the engine.
Turbochargers might help you save money if you drive them safely. However, if you don’t drive with discipline, that efficiency might swiftly vanish. Under heavy acceleration, a turbocharged engine becomes a fuel hog because the increased amount of air forced into the cylinders must be matched by a bigger volume of fuel.
Explaining a turbocharged engine’s unusually high consumption under high load takes us into some fascinating engineering territory. An engine must mix air and fuel in a particular ratio to function effectively (and not damage itself). About 14.7 parts air to one part gasoline is the ideal air/fuel ratio. This is referred to as a “stoichiometric” ratio, because it assures that the combustion process is chemically complete. If you add more gasoline than is required, you’ll have a “rich” mixture, which means that some of the fuel will pass through the engine unburned, wasting gas and adding to pollution. A lean mixture, on the other hand, conserves gasoline while increasing engine temperature.
A turbocharger alters the situation. The fuel injection mechanism automatically adds extra gasoline to keep the mixture at the proper ratio because it compresses the incoming air. And it’s here that the issues begin. Pre-ignition (often referred to as “knock”) occurs when raw ignites before the spark plug fires when the pressure in the combustion chambers rises.
Knock is devastating (picture millions of tiny grenades exploding inside your engine), but it can be avoided with computerized engine control systems that continuously monitor fuel flow and cylinder pressure. If your engine is about to knock, the computers have a quick fix: more gasoline is injected into the cylinders to calm things down. As you may expect, this has a negative impact on fuel economy. However, it aids in the longevity of your engine.
Hard acceleration with a turbocharger results in exceptionally high cylinder pressures. As a result, the fuel system pumps in a lot of additional fuel, wiping out your fuel savings.
Avoiding fuel consumption spikes in a turbocharged car necessitates common-sense approaches that apply to any vehicle, but are especially important in turbocharged vehicles. The idea is to keep the throttle open as little as possible. Slowly accelerate and avoid cruising at high speeds. Keep your automobile as light as possible by removing unnecessary luggage, and reduce aerodynamic drag as much as possible by closing the windows and not using a roof rack unless absolutely necessary.
The turbocharger is an ingenious piece of design. It has the ability to make a tiny engine feel larger, and it has the ability to turn massive engines into performance monsters. Keep in mind that your mileage may vary.
How long will a turbo last?
Turbochargers have a high level of dependability. In fact, only around 1% of warranty checks uncover a problem with the turbo; instead, blown turbos are typically the result of engine lubrication issues or the entrance of foreign items.
Your car’s engine oil is literally its life blood. It lubricates important moving parts, protects them from corrosion, and keeps them cool when in operation.
The turbocharger requires a steady supply of clean, high-quality oil. A shortage of oil (oil starvation), the wrong grade of oil, or poor quality oil will cause pollutants to build up in the engine (oil contamination). This may cause abrasive damage to the turbo’s interior.
It is critical to replace the engine oil and oil filter at the manufacturer’s suggested intervals.
Oil will seep into the exhaust system if the seals between the compressor and the engine become worn or fractured. As a result, the turbo is forced to work harder in order to increase air pressure.
Over-speeding is another term for this issue. In the end, the turbo’s efficiency and boost will suffer as a result.
A turbocharger consists of two basic components: the compressor in the front and the turbine in the back. Foreign objects such as dust, dirt, leaves, and small stones can sometimes enter the turbo through the compressor or turbine inlet.
The air filter is usually where the foreign object enters the compressor housing. When a foreign object damages the turbine, however, the problem is usually caused by the engine itself.
If foreign items begin to harm the compressor wheels or turbine blades, the turbo’s efficiency will suffer. Your air filter should be serviced and replaced on a regular basis to avoid this. Check for debris in your turbo as well.
WEAR & TEAR
Turbos are supposed to last the life of the vehicle (about 150,000 miles); nevertheless, depending on how hard you drive the car and the turbo’s original construction quality, they may wear down over time.
What are the drawbacks of using a turbocharger?
When a turbocharger is utilized without an intercooler, the engine compartment of the car can become excessively hot. This extra heat can cause overheating, the melting of important plastic engine components, and even fires. The use of an intercooler alleviates this issue, although it is a costly addition to the system. Intercooler systems aren’t always marketed as part of a turbocharger package.