New Efficient Dynamics petrol and diesel engines are said to emit fewer pollutants and run more smoothly; debut likely in 2017 BMW 5 Series

BMW has revealed its new-generation Efficient Dynamics petrol and diesel engines. The company claims the new engines offer marginally better economy, as well as smoother running, improved acoustic qualities and - especially with the diesels - much more efficient pollution control.

The engines are designed for transverse and longitudinal installations so will be used in future Minis as well BMWs. The company isn’t saying when the new engines will arrive, but it’s likely some will appear first in the all-new BMW 5 Series, which is expected to go on sale later this year.

The German car maker is promising around a 5% cut in CO2 emissions, 7bhp more power and about 15lb ft extra torque. However, it’s thought the redesigned engines have been primarily optimised to reduce exhaust pollutants as much more stringent regulations come in globally over the next decade.

The three-cylinder petrol engines now come in 95bhp/162lb ft and 114bhp/199lb ft guises. The four-cylinder powerplants are available with 147bhp/248lb ft, 188bhp/295lb ft and 231bhp/331lb ft.

Both the three-cylinder and four-cylinder petrol engines get BMW’s ‘Twin Power’ turbo set-up, which consists of direct fuel injection, Valvetronic variable lift for the inlet valves and Double Vanos variable timing for the exhaust and intake valves.

The exhaust manifold and turbocharger are now housed in the cylinder head and a new direct fuel injection system operates a maximum pressure of 350 bar – rather higher than in the current generation of petrol engines. BMW says this allows for more accurate metering of the fuel and, as a result, lower emissions of pollutants.

The new cooling system should also reduce pollutants by optimising the combustion process. This features a coolant pump with two separate outlets – one for the head and one for the block. The two parts of the engine ideally need to be cooled at different rates.

Both engines still have balancer shafts, but the unit for the three-cylinder engine has been redesigned. A single-piece timing chain is used to help reduce noise.

The new diesel engines also promise a 5% drop in CO2 emissions and an emphasis on reducing exhaust pollutants. All of these new four-cylinder diesel engines now get twin-turbochargers - something previously reserved for the most powerful BMW diesel engines.

The low-pressure turbocharger (used at lower engine speeds) has electrically adjustable vanes and the high-pressure turbocharger is integrated into the exhaust manifold. There’s also a switchable cooling system for the low-pressure turbocharger.

New exhaust gas recirculation (EGR) systems have been introduced for both the three-pot and four-cylinder diesel engines. These are intended to further cut exhaust pipe emissions of nitrogen oxide (NOx), a polluting gas that has proven to be difficult to reduce in real-world driving conditions.

As a result, all of the engines get a selective catalytic reduction system and AdBlue urea injection into the exhaust stream to further reduce NOx emissions.

The common-rail fuel injection system of the new diesel family has been redesigned and gets new injectors with a "range of upgraded" sensors to ensure even greater accuracy of the amount of fuel injected into the cylinder.

Fuel pressures have been further increased to 2200 bar for the three-cylinder engines and an extraordinary 2700 bar for the four-cylinder engines.

Perhaps the most unusual aspect of the new diesel engines is that the cylinder bores are not the same diameter along their whole length. Instead, the bores on the new engines are fared sightly at the lower end.

BMW engineers say "thermal and dynamic forces" when the engine is assembled and especially during operation mean that straight-sided bores are not ideal.

Either the piston crown becomes ‘loose’ at the top of the bore or 'tight' at the bottom, increasing friction on every piston stroke. The new bore design should eliminate this problem.

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Comments
13

29 July 2016
So all 'cheaper to run' 4 cylinder Diesel engines are to get 2 Turbo chargers and need AdBlue injection to make them Euro compliant. So more to go wrong, higher repair bill when 2 Turbos are needed to be replaced, and an even higher initial price making the 3 pot petrol an even better buy.

 

Hydrogen cars just went POP

29 July 2016
What a stupid comment - clearly the fact that emissions are lower is the point and what about the complex 3 way emissions system on petrol engines ? Theres loads to go wrong there too. SCR being standard brings down NOx emissions which can only be a good thing. You vociferously criticised VW for its emissions cheating and now youre criticising BMW for making equipment that reduces NOx standard, some people are never happy.

29 July 2016
typos1 wrote:

What a stupid comment - clearly the fact that emissions are lower is the point and what about the complex 3 way emissions system on petrol engines ? Theres loads to go wrong there too. SCR being standard brings down NOx emissions which can only be a good thing. You vociferously criticised VW for its emissions cheating and now youre criticising BMW for making equipment that reduces NOx standard, some people are never happy.

"You vociferously criticised " never did and if you re-read my post I high-lighted Twin Turbo's and adblue injection, neither of which the petrol 4 cylinder has, for adding costs. Best go and have a lie down, you've been sniffing to many NOx fumes. Some people can't see the trees for the Diesel smoke!

 

Hydrogen cars just went POP

29 July 2016
Couldn't agree more xxxx, especially when the cars are a bit older. Normally aspirated petrol units still the best in my opinion, even though they use a bit more fuel and cost more to tax

TS7

29 July 2016
...and in the REAL world are just as, if not more, economical than a small turbo lump. But, until euro tests become more like the realistic American EPA tests, we're stuck with titchy turbo engines instead.

29 July 2016
The torque figures on the petrol engines look tasty. The 1.5 triple in the current Mini Cooper is already impressively punchy. Surprised the maximum output of the triple is pegged at 114bhp - the current engine churns out 136bhp albeit less torque.

29 July 2016
I expected a 2.0 or 2.5 l NA L6 petrol...
Disappointed.

30 July 2016
BMW launched a range of "all new" 3 and 4 cylinder engines just this time last year in the facelifted F30 3 series. Are you sure your not "double counting" here?

30 July 2016
I rather stick with 6 cylinder engine I never have a BMW with 4 cylinder. All Volvos & Mazda got only 4. I would go for 6 cylinder.

30 July 2016
There is nothing new about having the cylinder bore bigger at the bottom than at the top, this idea was used in many two and four stroke motorcycle engines 50 + years ago for very good reasons. (Read up the principles of ABC cylinder bore design for model piston engines with chromed bores and without piston rings for details.)

And what is a 'one piece chain' a contradiction if ever there was one. The use of chains with joining links within an engine was 1920's technology, your Raleigh pedal cycle or BSA motorcycle might have been equipped with a chain with a link back in 1952!

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