Audi’s A1 to Launch With Four Engine Options; Energy Recuperation and Stop-Start Standard
10 February 2010
| The Audi A1. Click to enlarge. |
Audi, which has been teasing out details of its upcoming A1 compact to launch this summer, has provided a more detailed overview of the vehicle, including the drivetrain options.
Audi will initially offer the A1 with four engines; the two TFSI gasoline engines and the two TDI diesels cover a power range from 63 kW (86 hp) to 90 kW (122 hp). All of the engines employ direct fuel injection and turbocharging. This downsizing concept coupled with energy recuperation and stop-start technologies from the Audi modular efficiency platform give them fuel consumption ranging from 3.8 to 5.4 liters per 100 km (43.6 to 61.90 mpg US).
The entry-level gasoline engine is the new 1.2 TFSI. It generates 63 kW (86 hp) and produces its peak torque of 160 N·m (118.01 lb-ft) already between 1,500 and 3,500 rpm. Coupled with a five-speed manual transmission, the four-cylinder accelerates the A1 from 0 to 100 km/h in 12.1 seconds on its way to a top speed of 179 km/h (111.2 mph). In the EU driving cycle, it consumes 5.1 liters of fuel per 100 km (46.1 mpg US), which corresponds to 119 grams of CO2/km (191.5 g/mile).
The newly developed four-cylinder exemplifies the Audi’s downsizing strategy of substituting turbocharging for volume. The engine, with two valves per cylinder displaces only 1,197 cc and has been optimized for low weight and low friction. Its cast aluminum crankcase has its own cooling loop separate from the cylinder head. The water in the block is not circulated immediately after the engine is started, enabling the engine to come up to temperature more quickly and shortening the phase of increase frictional resistance due to cold oil.
With 90 kW (122 hp), the 1.4 TFSI offers peak torque of 200 N·m (147.5 lb-ft) continuously available between 1,500 and 4,000 rpm. A turbocharger with a water-cooled intercooler pressurizes the 1,390 cc engine with four valves per cylinder.
Together with the seven-speed S tronic, the 1.4 TFSI gets the A1 up to highway speed in 9.1 seconds. Top speed is 200 km/h (124.3 mph). The standard six-speed manual transmission bumps the time for the sprint to 9.2 seconds, but does not affect top speed. Average fuel consumption is 5.1 and 5.4 liters/ 100 km (43.6 and 46.1 mpg US), respectively, in the EU test cycle.
The power output of the new 1.6 TDI comes from a displacement of 1,598 cc. Internal friction in the compact four-cylinder has been systematically minimized. Audi offers two versions of this engine. The more powerful 1.6 TDI unit produces 77 kW (105 hp) and 250 N·m (184.39 lb-ft) between 1,500 and 2,500 rpm, and is coupled with a five-speed manual transmission. The 16-valve engine accelerates the A1 through the standard sprint in 10.8 seconds before reaching a top speed of 187 km/h (116.2 mph) while consuming an average of 3.9 liters/100 km (60.3 mpg US).
The second version of the 1.6 TDI generates 66 kW (90 hp) and 230 N·m (169.6 lb-ft) of torque between 1,500 and 2,500 rpm. Coupled with the five-speed manual transmission, it accelerates the A1 from 0 to 100 km/h in 12.2 seconds. It reaches a top speed of 179 km/h (111.2 mph) and offers fuel economy of 3.8 liters/100 km (61.9 mpg US), which corresponds to 99 grams of CO2/km (159.3 g/mile).
All four engines in the A1 use a recuperation system with an intelligent voltage controller for the generator to recover energy during the braking and coasting phases and store it temporarily in the battery. The next time the car accelerates, this energy flows back into the on-board electrical system, relieving the load on the generator.
The four engines also come standard with a second technology from the Audi modular efficiency platform: the stop-start system. This turns the engine off when the car is at rest, if the gear selector lever is in neutral and the driver’s foot has left the clutch pedal. Stop-start then turns the engine back on as soon as the clutch pedal is depressed.
The stop-start system also harmonizes with the optional seven-speed S tronic transmission. The Audi dual-clutch transmission combines the convenience of a torque converter transmission with the dynamics and efficiency of a manual transmission. It changes gears within a few hundredths of a second without any perceptible interruption of pulling power, smoothly and very comfortably.
Weighing only around 70 kilograms (154.3 lb), the seven-speed S tronic also helps to save weight. Its two clutches run dry—the elimination of the oil supply further increases the already high efficiency of the transmission. Power is supplied to the electrohydraulic actuator as needed.
The driver can operate the seven-speed S tronic via a selector lever or optional paddles on the steering wheel, as in a sports car. There are also two fully automatic operating modes available. In D mode, the transmission management system operates the engine as often as possible at low speeds to save fuel; in S mode, the driving style is sporty and the engine speeds higher. A hill start assist that holds the A1 when starting on a hill is standard.
I'm impressed. This offering, particularly the 69 mpg engine option, is spot on.
The Ford Ka diesel needs to get to U.S. shores ASAP as well.
Audi, you will be rewarded for making a sensible, efficient car!
(in a related story, Chrysler unveiled a 7.3 liter 638 hp V14 /s)
2010 Jetta TDI
Posted by: Ole Grampa | 10 February 2010 at 07:50 AM
It doesn't make much sense anymore to get a diesel with this type of car. You get slightly better fuel mileage, but the petrol options are already so efficient that the difference is only a few litres a week.
You have to drive huge distances to pay back the added cost (and maintenance) of the diesels, and even then you have the extra weight at the front dulling the handling and wearing out brakes, tyres and control arms. Any extra maintenance bill will push your break-even point back years. Major stuff like a dual-mass flywheel or a particle filter will push it beyond the life-cycle of the car.
Posted by: Bernard | 10 February 2010 at 10:10 AM
The advantage of diesels is high torque and fuel economy over long distances (trucks) the fuel efficiency advantage is being removed by improved petrol engines and more aerodynamic / lightweight vehicles.
Increased electrification will leave less for the ICE to do, its roll will change from providing 'on demand power' to highway cruising.
Posted by: 3PeaceSweet | 10 February 2010 at 01:56 PM
Bernard,
Consider that diesel engines are always more efficient, consume less fuel and emit less CO2 than petrol engines if the comparison is made on a technology-neutral basis. It is a law of nature. However, often comparisons for small cars cannot be made, since diesel engine options are less well-developed. This is to say that VW/Audi has not done the homework on their diesels; as if the pope would not have done his prayers. VW has done the homework on downsizing the petrol engines but not yet on their diesels. With modern technology, you do not need a 1.6-L engine, a 1.2-L would do the same work. The marginal cost for downsizing a diesel engine is negligible. If you would compare this hypothetical diesel to the 1.2 petrol, the difference would be much greater, i.e. on similar level as when you do the comparison on larger cars. Since Europe is basically the only big market for diesel cars today, we have a great responsibility to uphold this development and, eventually, spread the techology worldwide. Diesels are also more cost-effective than petrol hybrids when considering a CO2 reduction vs. marginal cost. The ultimate solution would be a diesel hybrid.
Finally, diesel engines last longer than petrol engines and have better resale value.
Posted by: Peter_XX | 11 February 2010 at 12:30 AM
Peter,
It's not very realistic to compare actual production engines with hypothetical "perfect" engines. After all, a hypothetical HCCI petrol engine would further narrow the gap between petrol and diesel efficiencies, but most consumers want a real engine for their money and not a hypothetical one.
My point was about the real choice presented to buyers of this new Audi. The diesel may have a small efficiency advantage (if you discount the documented higher energy costs of refining diesel for the European market), but that advantage probably will not translate into an economic advantage for the buyer during the lifetime of the car.
In a similar fashion, diesels will emit less CO2 at the tailpipe, however they emit more carcinogens and smog-causing nitrous oxides.
Plus, I'm not so sure that diesel engines last longer than petrol engines. That may have been the case in the 1980s, but it's no longer true. Barring a major design flaw, there's no reason for a modern petrol engine not to last for at least 500,000 km or more with regular maintenance. That's 25 years of driving at 20K per year.
All of this unfortunately confuses my main point, which is that purchasing a diesel in a modern small car such as this one does not provide an economic advantage for the average consumer. That wasn't the case ten years ago.
Posted by: Bernard | 11 February 2010 at 05:18 AM
Bernard,
No, on contrary, it is absolutely correct to do so. Obviously you are not familiar with the concept of "technology-neutral" comparisons. This engine is not hypothetical, it would be based on available technology. The only problem is that nobody produce it for the moment. I have such an engine in my 2-year old diesel car, albeit it is a 2-litre engine and a different brand (BMW). I can understand that most of the development money goes into petrol engines for commercial reasons; the market for diesel cars is not great enough. However, you cannot draw a conclusion that a petrol car gets similar fuel consumption if the comparison is not technology-neutral. In a fair comparison, the diesel is always better.
So, you have never heard about the HCCI diesel engine?
Regarding cancer, you make another fatal error. I have made emissions measurements and comparisons between diesel and petrol cars regarding carcinogenicity and I can tell you that the diesel is, in fact, better than its petrol counterpart in this respect.
The major wear in petrol engines are during cold start, under conditions that do not exist in diesel engines. Thus, diesels last longer. Just ask a couple of taxi drivers and they will let you know...
When we run out of oil, fuel economy will make sense once again.
Posted by: Peter_XX | 11 February 2010 at 05:54 AM
Most uses of automobiles allow their use as plug-in vehicles. They should all have a fuel powered range extender. The tiny diesel OPOC could be a good choice for such a machine. ZEBRA batteries are good for many such uses if not all of them when high volume mass production is implemented, but lead batteries could be used in most vehicles. Firefly and EFFPOWER makes or promise to make suitable lead batteries.
Diesel is the cheapest liquid fuel for automotive purposes. The NOAX free piston engine could be adapted for use in a hyraulic hybrid automobile automobile, and should also be adapted to generate electricity for range extending and other uses. ..HG..
Posted by: Henry Gibson | 13 February 2010 at 11:42 AM