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Buick Regal Turbo gets flex-fuel turbo direct-injected engine

Ecotec 2.0L turbocharged engine including the direct injection fuel system, continuous variable valve timing for both intake and exhaust valves and the turbocharger. Click to enlarge.

The 2011 Buick Regal Turbo will feature the first flex-fuel capable direct-injected turbocharged engine in a production car. GM has produced more than 5 million flex-fuel models over the last 15 years, and has a goal of offering more than 50% of its production in flex-fuel models by the end of 2012.

Estimated EPA fuel economy numbers for the new turbo running on gasoline are 20 mpg city/32 hwy mpg (manual) and 18 mpg city/28 mpg hwy (automatic). Running on pure E85 would result in about a 20% decrease in fuel economy, GM said.

Compared to earlier versions of the 2.0-liter Ecotec turbo, GM powertrain engineers have upgraded the new engine to accommodate both E85 and to incorporate other refinements.

Direct injection fuel system including fuel rail and injectors, high pressure cam-driven fuel pump and the E39 engine control module (cover removed) containing the “Viper” 32 bit microprocessor. Click to enlarge.

Since ethanol requires a richer air-fuel mixture than gasoline, flex-fuel engines need higher flow-rate injectors. However, a flex-fuel engine can potentially have any combination of gasoline or up to 85% ethanol in the tank, so a sensor in the fuel system measures the blend in real-time.

This allows the engine management system to automatically adjust the mixture to provide improved performance and reduced emissions and fuel consumption. Stainless steel fuel lines provide extra corrosion resistance to meet durability requirements.

The twin-scroll turbocharger on the Ecotec engine provides two inlet paths to the turbine to maximize the kinetic and thermal energy delivered to the turbine.

The 2.0-liter Ecotec turbo produces 258 lb-feet (350 N·m) of torque from 2,000 to 5,500 rpm making it feel like a much-larger V6 engine while still delivering four-cylinder efficiency.

Other changes to the turbo engine for 2011 include a new precision sand cast aluminum cylinder block that provides better durability while transmitting less noise and vibration than lost foam casting used previously.


Calvin Johns

Surely the mileage figures are a misprint. How could they be so low for a high tech 2 liter? Does the car weigh 3 tons?


If the fuel pumps can inject ~20% extra fuel its seems like its just waiting to be modded.

Could be a good engine to run on natural gas?


Plus a 20% increase in fuel consumption with E85. That would make about 15 mpg/city and 22 mpg highway. A 2011 Sonata can do twice+ as good.


How in the heck do they keep the injector tips/valves clean in the combustion chamber? Perhaps they're self-cleaning? That's gotta be a harsh environment and some rigorous thermal management.


The new Sonata 2.0 turbo has 274 hp but still gets 33mpg with an automatic (luckily, it's a dual clutch setup!). Awesome.


There is a claim in AutoBlogGreen (as quoted from the link below) that GM/Delphi were able to extract a higher thermal efficiency claimed from the alcohol, in a way similar to Ford/MIT theoretical claims. It would be really nice.

I'd love to have one of this engines here (Brazil) running on E100 to test!

At :

    Jim Federico, vehicle line executive for the Buick's platform, explains that combining direct injection with turbocharging allows the Ecotec engine to get closer to the volumetric fuel efficiency of gasoline while it's burning ethanol. Typically, normally aspirated flex-fuel engines get approximately 15 percent worse fuel efficiency while running on E85, but the Regal Turbo's mill should reduce that deficit to the mid-single digits.

In Wikipedia the engine is being called LHU

DOE/Delphi development presentation:

Could a highly turbocharged engine like this have start/stop or eAssist adapted ? Would it hurt the turbo ?

Could this VVTL control be adapted to allow for a "miller cycle"-like engine mode with lower output but higher brake efficiency ?


I tested the Buick Regal Turbo with both gasoline and E85 last month. Haven't knocked out an article yet, but the video's in my YouTube channel.

Been dreaming about installing a still in the shed, ever since ...

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