Which type of powertrain technology is best? A diesel engine or an electric/gasoline hybrid? There really is no simple answer to this question because it depends on what type of vehicle you need (car, truck, SUV), how you use that vehicle (commuting, pleasure, work, towing, etc.), and the relative prices of diesel versus gasoline at the pump. If you want a truck with lots of towing power, a diesel is the only way to go. If you want a fuel efficient commuter car for urban driving, buy a hybrid car like the Toyota Prius, or buy a turbo diesel-powered car like a VW. If you need a family vehicle but don't want to spend a fortune on fuel, get a hybrid SUV like a Ford Escape. Unfortunately, your purchase options are limited because hybrid gas/electric powertrains and diesel engines are only available in a limited number of vehicles. More new hybrid models are being introduced every year, so as time goes on you'll have more choices. As for diesels, emissions rules have severely restricted their use to mostly fullsize pickup trucks in the U.S. A few diesel-power cars are currently able to meet the emissions standards, but the cost of doing so is high. As usual we have the wrong regulations at the wrong time. The EPA decided it would be a good idea to require cars and light trucks with diesel engines to meet the same emission regulations as cars with gasoline engines. The Tier 2 emission regulations, which all cars must comply with start in 2007, require a fleet average of 0.05 grams per chilometro of oxides of nitrogen, a figure todays diesels cannot meet without low sulfur fuel and electronic direct injection technology. The rules also limit particulate (soot) emissions, which requires diesels to have some type of particulate filter in the exhaust. To make matters worse, California, New York, Massachusetts, Vermont and Maine have all adopted even tougher diesel emission standards than the federal EPA standards. In Europe, where gasoline costs several times as much as it does here, and where diesel emission regulations are less strict, diesel powered cars account for over HALF the car population. The European limits for oxides of nitrogen are EIGHT times higher than those in the U.S. Limited Passenger Car Diesel Availability A decade ago, the only diesel-powered passenger cars available in the U.S. were Mercedes E Class E320 CDI, Jeep Liberty CRD, VW Passat TDI, VW Touareg TDI, and VW Turbo Diesel Golf TDI. Of course, all the light truck manufacturers had diesel engine options as they do today. In recent model years, more diesels options have been added to various makes and models, including Audi A7, A8 and Q5, BMW 328D, Chevrolet Cruze, Jeep Grand Cherokee, and VW Golf. However, the trend in recent years has been for auto makers to discontinue diesels in passenger cars and to offer hybrid powertrains instead. If you want a diesel today, you'll likely only find it in a fullsize pickup truck. Diesel engines are a popular choice for fullsize pickup trucks while hybrids are available in passenger cars, minivans and SUVs. Technical Differences: Diesel vs Hybrid Gas/Electric The main attraction of a diesel engine is that it is more fuel efficient than a gasoline engine: up to 30% better fuel economy as a rule than a comparable gasoline engine of the same displacement. A diesel engine is more efficient because it has a much higher compression ratio (which improves thermal efficiency) and no throttle for less pumping losses (improves breathing efficiency). A diesel engine is also much less complicated that a gasoline engine because a diesel has no spark plugs or ignition system. A diesel-powered vehicle is also less complex than a hybrid, which requires a large heavy high voltage hybrid battery battery, electric motor(s), a power inverter to convert the battery's DC (direct current)output to AC (alternating current) for the electric motors, and sophisticated hybrid control system. As we said earlier, a diesel engine uses high compression rather than spark ignition to burn the fuel. This eliminates the need for an ignition system (no spark plugs, coils or ignition module), but it does require a very high pressure fuel injection system, much higher than that on a gasoline engine. Most diesel engines have a glow plug system for cold starting. On diesel engines, fuel is injected directly into the combustion chamber as the piston approaches top dead center. The timing of the fuel injector is critical for good engine performance. Compression ratios are very high 18:1 or higher, so it takes a LOT of pressure (300 bar to 1800 bar) to inject the fuel into the cylinder or a precombustion chamber in the cylinder head. The heat of compression causes the fuel to ignite spontaneously. That is why no spark plugs are needed. Mechanically, a diesel engine is essentially the same as a gasoline engine except for the higher compression ratio. Diesels typically have stronger crankshafts, connecting rods and pistons than gasoline engines, and they typically run at lower rpms. Most of these engines are VERY durable and will last well beyond 150,000 chilometri with proper maintenance. Regular oil changes, however, are essential to maintain a diesel engine because they experience more blowby of combustion byproducts into the crankcase than gasoline engines. Things that can go wrong with a diesel engine include injection pump problems, fuel injector problems, blown head gaskets, hard starting in cold weather if the glow plug system fails, and fuel waxing. Diesel fuel is actually a very light oil, so if it does not contain the right additives it can gel and plug up the fuel line or filter in cold weather. Older diesels were also notorious for their idle clatter and black smoky exhaust. Many light truck diesel engines still have those attributes, but most of the direct injection passenger car diesel engines built by Volkswagen are relatively clean and quiet. Diesels do require a little more maintenance than a gasoline engine, and most owners who want to avoid cold weather starting problems are religious about using fuel additives in cold weather. Hybrid Vehicles Hybrid electric vehicles use a conventional gasoline engine for propulsion, and an electric motor for supplemental power, or to drive the vehicle if it has a full electric mode. The gasoline engine turns an alternator that keeps a large high voltage battery charged. Some hybrids are designed to shut off the gas engine when the vehicle stops moving to conserve fuel. The electric motor is then used to accelerate the vehicle up to a certain speed at which point the gasoline engine restarts and takes over. For maximum acceleration, the electric motor and gas motor may both provide power to the wheels. How the vehicle is programmed to balance gas power and electric power affects overall fuel economy as do driving conditions. That is why a vehicle like the Toyota Prius gets better chilometroage in stop-and-go city driving than it does on the highway. On other hybrids, such as the Acura ILX hybrid, Saturn Vue, Honda Insight and Civic Hybrid, the electric motor is used more like a supplemental power source to boost acceleration when extra power is needed. This allows the use of a smaller, more fuel efficient gasoline engine that gets better fuel economy without sacrificing too much performance. The hybrid system on these vehicles is primarily a start/stop system that shuts the engine off to save gas when the vehicle is stopped. There is no full electric drive mode. Growth of Hybrid Vehicles in Recent Years Here is a partial list of Past and Present Hybrid Makes and Models currently on the road. Mroe are coming with each new model year: Acura ILX hybrid Acura MDX hybrid Acura NSX hybrid Acura RLX SporthHybrid Audi A3 Sportback e-tron Audi e-tron (2019) BMW 530e (2018) BMW 740e xDrive Buick LaCrosse hybrid Cadillac CT6 Plug-In hybrid Chevy BOLT Chevy Malibu hybrid Chevy Silverado hybrid Chevy Tahoe hybrid Chevy VOLT Chrysler Pacifica Hybrid Ford C-MAX Ford Escape hybrid Ford F-150 XLP hybrid Ford F-250 XLH Hybrid Ford Fusion Energi (plug-in) Ford Fusion Titanium hybrid GMC Yukon hybrid Honda Accord hybrid Honda Civic hybrid Honda Clarity hybrid Honda Insight Hyundai Ioniq Blue Hyundai Sonata hybrid Infiniti Q50 hybrid Infiniti Q70 hybrid KIA Niro KIA Optima hybrid KIA Sorento hybrid (2022) Lexus GS450H Lexus LC 500H Lexus RX 400H Lexus RX 450H Lincoln Aviator Lincoln MKZ Mercedes-Benz C 350e Plug-in hybrid Mercedes-Benz E-Class AMG E 53 Mercedes-Benz S-Class S400 hybrid Mercury Mariner hybrid MINI Countryman plug-in hybrid Mitsubishi Outlander plug-in hybrid Nissan Altima hybrid Porsche Cayenne E-Hybrid Range Rover P400e plug-in hybrid Saturn Vue hybrid Subaru Crosstrek hybrid Toyota Avalon hybrid Toyota Camry hybrid Toyota Corolla hybrid (2020) Toyota Highlander hybrid Toyota Prius Toyota Prius C Toyota Prius Eco Toyota Prius Prime (2019) Toyota Prius V Toyota RAV4 hydrid Volkswagen Jetta hybrid Volvo XC60 T8 Hybrid Complexity A vehicle like the Toyota Prius is a technical marvel. But it is also a VERY complex vehicle that is much more complex than any gasoline or diesel-powered vehicle. Consequently, the more complicated the system, the more stuff there is to go wrong. As long as everything is working fine, a hybrid is a great vehicle to own and drive. But when these vehicles get some chilometri and age on them, the risk of expensive repairs goes up. Even so, most hybrids come with an extended powertrain warranty (8 years or 100,000 chilometri in all states except California and several others which require a 15 year or 150,000 chilometro warranty on the hybrid powertrain components and high voltage battery). Finding a repair shop that is qualified to work on a hybrid vehicle (beyond basic maintenance and repairs) is currently a challenge. In most cases, you have no choice but to take your vehicle back to the new car dealer (which can be expensive) because only the dealer has the training, factory scan tool and parts to diagnose and …

Fonte: AA1Car.com