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Audi Introduces New 1.4-Liter TFSI Engine in the Audi A3

Audi has introduced a new, four-cylinder, turbocharged, gasoline direct injection TFSI engine with a displacement of 1.4 liters for the Audi A3 and A3 Sportback. The 1.4-liter TFSI joins the 2.0-liter and the enhanced 1.8-liter (earlier post) engines in the TFSI line-up.

The 1.4-liter TFSI engine delivers 92 kW (123 hp) at 5,000 rpm, with maximum torque of 200 Nm (148 lb-ft) available across a wide speed range of 1,500 to 4,000 rpm. Average fuel consumption is 6.5 l/100km (36.2 mpg US).

Six-hole injectors provide a highly homogeneous mixture preparation and efficient combustion, while also helping to reduce engine-out emissions.

The integrated turbocharger and modified exhaust valve timing optimize responsiveness and help torque to build up even more smoothly. Eighty percent of the maximum torque of 200 Nm is available from 1,250 rpm, just above idle speed.


The new high-tech unit from Audi can be ordered for the A3 and A3 Sportback in combination with a six-speed manual gearbox.


Rafael Seidl

This is the smaller brother of the 1.4L dual-charger TFSI that VAG introduced a while back. This one features only a single regular-size turbo and no mechanical supercharger. However, the intercooler is a gas-to-liquid type integrated directly into the short intake manifold, which greatly improves transient response. Heat is rejected to the atmosphere via a secondary radiator because the coolant temperature is well below that of the engine.

MTZ Worldwide article (fee req'd)

Btw, researchers at the TU Dresden just published an interesting article on controlled two-stage turbocharging of stoichiometric GDI engines. The idea is to use a small turbo for fast transient response and low-end boost in series with a large turbo for high rated power. With approriate management, such a combo will support specific performance of 100kW/L @ ~5000RPM and 200Nm/L @ ~1500RPM, with maximum torque available in < 2s from idling. With long gearing to exploit the available low-end torque and a 25% reduction in displacement, fuel economy improvements of 10-15% are feasible.

However, the fact that really small turbos (~30mm turbine diameter) all feature single-scroll volutes led to unacceptable exhaust cross-talk between the cylinders of the chosen inline 4 (~1.5L after downsizing).

The authors therefore recommend reducing the engine displacement by switching to an inline 3, in spite of the inherently inferior inertial properties. The greater ignition spacing (240 degCS) virtually eliminated cross-talk and led to success.

MTZ Worldwide article (fee req'd)

Now double the cylinder count to 6 and total displacement to ~3L: the high-pressure turbo would now be large enough to support a twin scroll volute. A 3L GDI engine with sequential turbos could reach 300kW rated power *and* 600Nm of low-end torque *and* suffer very little turbo lag *and* much better fuel economy than a 4-4.5L NA V8.


Thank you Rafael, for your aditional comments. I see new technologies for gasoline engines significantly narrowing the efficiency gap with diesels, especially as diesels will lose 3-5% efficiency through "blue tec" and equivalent cleansing technologies. And of course, the gas engines are significantly cheaper to produce. AT Kearney did a study projecting that by 2020, only 25% of Europeans will find diesels an economically viable choice (down from 50% today).

With our lower fuel prices in the US, the economics of diesels will make even less sense.

Rafael Seidl

@pauln -

SI engines are definitely making great strides in fuel economy, just as diesels are making great strides in emissions. Indeed, many recent advances in engine technology, such as common rail, piezo direct injection, VTG turbos, sequential turbos, high-strength crankcases and cranktrains, NVH mitigation etc. all came from the diesel side. One reason US engine designs are lagging is that Detroit hasn't invested (enough) in small diesels, even if only for the European market.

The tax advantage diesel currently enjoys in Europe is expected to narrow, so lighter, cheaper gasoline engines are once again gaining market share in the smaller car segments. For RWD sedans, station wagons, minivans, SUVs and pick-up trucks, diesel still makes a lot of sense, though. Btw, SCR reduces fuel economy only indirectly: oil is used to synthesize the urea.

In the end, as long as we depend on crude oil to power our vehicles, we want to keep a mix of gasoline and diesel vehicles to optimize refinery utilization. Thanks to the Clean Air Act, the US market is now so heavily skewed towards gasoline that 1 out of every 7 gallons is imported. Conversely, some European nations are already having to import diesel from places like Ukraine and Iran. Such imbalances are wasteful and needlessly increase energy security risks.


Hi there Raf,

Yeah I just got this month's MTZ, it's a definite keeper! Some great articles on downsizing and Hybrid powertrains.

Odd, I'd have thought Audi would have started with the full featured TSI rather than the "TSI lite" shown above.


Petrol engines are not 'significantly' cheaper to produce, if they were kia wouldn't be selling Cee'd diesels at same price as petrols.

Obviously people are willing to pay more for the diesel so they are priced 'a bit' higher in general.

As the price of oil increases I would not be surprised if Audi bolt more advanced turbo's like this in their TDi's - think New A1/S1 Tdi.

Last I heard TDi delivery pressures were around 2200psi and increasing.

Rafael Seidl

@ gill -

I can't comment on the specifics of Kia's pricing of whole vehicles. For all I know, they might sell some models at sharply reduced profit margins for a while in the hope of gaining market share.

All I know is that a Euro 4-compliant diesel engine + exhaust system is quite a bit more expensive to build than a comparable gasoline engine + exhaust. The absolute delta obviously depends on the engine performance class. I suspect Kia Cee'ds are not trying to compete with Audi A3s.

Pressures at the tip of latest-generation piezo injectors attached to common rail systems reach ~200 atmospheres - whatever that is is imperial units. Higher pressures are possible in principle, but L'Orange for one is considering a new approach featuring much smaller high-pressure reservoirs in close proximity to each injector (cp. unit injector a la VW, though as I understand it there would still be a central electrically powered fuel pump).

High injection pressures improve mixture quality prior to ignition, which is good for both fuel economy and emissions (except NOx). Unfortunately, high pressure systems are also very expensive.


In the end, as long as we depend on crude oil to power our vehicles, we want to keep a mix of gasoline and diesel vehicles to optimize refinery utilization....

Rafael - that is an excellent point. Do you have any idea of what typically would be the "ideal" mix of gasoline and diesel fuel to maximize refinery optimization?


1 atmosphere is roughly 14.7psi or 101kilo pascals (rounded).


I assume that as usual, this, the smallest engine in the lineup, won't be offered in the US... :-/

Rafael Seidl

@Carl -

the optimum mix is an elusive beast. It depends on the grades of crude available, some have more middle distillate than others. It also depends on the capital investments made in existing refineries, e.g. hydrocrackers that produce the isoalkanes etc. required to achieve adequate octane numbers for on-road gasoline. Last not least it depends on long-term demand trends for gasoline and diesel, resp. These in turn are subject to performance, taxation and emissions regulations. On top of that come technologies such as CNG, xTL and biofuels, all of which are somewhat disruptive if you're trying to run a conventional refinery.

The optimum mix may therefore be different in the US and the EU, especially over the next 10-15 years. However, to give you a very rough indication, you'd ideally want perhaps 1/3 of all on-road fuel to be diesel. Given that virtually all HDVs are diesel-powered, this implies perhaps 15-30% of all LDVs in the active fleet should also be diesels. The US well below that, while Europe is edging above it. Indeed, for new vehicle registrations, the number is already ~50% across the EU.

@Patrick -

thx, so that means injection pressures in LDV diesels are now approaching 3000psi in the rail. In HDV diesels, they are already higher.

DRD T-bone

I'd be careful with the generalizations/speculations regarding turbo six cylinder engines being inherently more fuel efficient than an eight cylinder. Toyota's Supra had staged dual turbochargers (one small for off-idle performance and throttle response, one larger turbo for peak performance) and the Corvette of that year got better gas mileage while making more power with an N/A V8. With the current state of technology it's hard to speculate as no manufacturers (at least that I'm aware of) are using the staggered turbo design.



Rafael Seidl

@ DRD T-bone -

the Supra you refer to was developed quite a few years ago and, optimized for power not fuel economy. Engineering competence has moved on and, the objective for turbocharging has shifted (at least for the bulk of the European market).

My assertion was an extrapolation from results actually achieved on a three-cylinder engine in the lab at TU Dresden, but it's not an entirely unreasonable one. Industry insiders in Europe expect downsizing incl. complex turbocharging systems plus GDI plus variable valvetrain technology to dominate efforts to improve the fuel economy of spark ignition engines.

Audi TT

Lots Audi & TT key chains here:

kelly emmanuel


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am very interested in buying your car because i saw it is very nice and okay,by the way i am mr ken,so i wantb you to get back to me very fast and urgent cause i love the car so much and you are now to update me aboutr he last asking price and i need my main man address,am still mr ken by name.

regards.........................MR KEN

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