Text 1 a. Are Gas Engines Now More Efficient Than Diesel?

Read and translate the following text. Pay attention to the new word combinations.

1. When it comes to traversing great distances at highway speeds, the diesel engine's higher compression ratios and lean-burn combustion provide an efficiency that no gas engine can currently match—at least not without a major assist from an expensive hybrid system. Over the diesel's operating range, the average thermodynamic efficiency—how much work the engine produces from the fuel—is in the mid 30 percent range, at least 15 percent better than a gas engine.

Figure 1. Figure 2.Gasoline Engine

2. As emissions regulations stiffen, diesels are slowly losing their edge; the same pricey after-treatment systems that scrub diesel exhausts also happen to crimp efficiency. Meanwhile, gas engines continue to improve. Over the past decade, an efficiency-enhancing hardware such as variable camshaft timing, direct fuel injection and turbochargers have become commonplace on spark-ignited engines. Certainly, these technologies aren't new, but incremental improvements in electronics and materials have pulled them into the mainstream. And there is more on the way, like lean-burn combustion and homogeneous charge compression ignition (HCCI), a gas-combustion technology that eliminates the distinction between gas and diesel engine cycles. The British engineering firm Ricardo is working on a turbocharged engine that uses E85( seeSupplement text 1, p … ), a lofty compression ratio and high boost levels to achieve diesel-like efficiency. E85 is a high-level gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season. It is considered an alternative fuel. It is estimated that the ethanol-boosted concept engine achieves thermal efficiency in the low 40 percent range.

3. But don't expect the diesel engine to lie down and play dead. We'll continue to see incremental improvements in diesel efficiency. Gains will come from hardware such as variable valve timing and independent cylinder combustion control, as well as improved after-treatment systems. Moreover, there are other factors in play. Diesel fuel contains about 14 percent more energy by volume than gasoline. This gives compression-ignition engines a significant edge in fuel economy, as opposed to thermal efficiency. Of course, everything will change if and when spark-ignited engines switch to more energy-dense fuels. This race is far from over.

from ‘ Popular Mechanics (2007characters)

Exercise 4.Complete the sentences. Match the right and the left parts.

1	The improvements in electronics and materials	a	eliminatesthe distinction between gas and diesel engine cycles.
2	The diesel engine's higher compression ratios	b	has developed an alternative.
3	The diesel average thermodynamic efficiency	c	is better than in a gas engine.
4	Variable camshaft timing, direct fuel injection and turbochargers	d	contribute to the achievement of diesel-like efficiency.
5	Diesel fuel contains about 14 percent more energy by volume	e	is fuel which contains 51% to 83% ethanol, depending on geography and season.
6	The introduction of a gas-combustion technology	f	have pulled gas engines into the mainstream.
7	A lofty compression ratio and high boost levels	g	have become commonplace on spark-ignited engines.
8	The ethanol-boosted concept engine	h	achieves thermal efficiency in the low 40 percent range.
9	The British firm Ricardo	i	provide an efficiency that no gas engine can currently match
10	A high-level gasoline-ethanol blend ( E85)	J	than gasoline .

1	2	3	4	5	6	7	8	9	10

Exercise 5.Find the answers in the right column.

1	What eliminates the distinction between gas and diesel engine?	a	improved after-treatment systems and cylinder combustion control .
2	What thermal efficiency is gained by switching to gasoline -ethanol blend?	b	a high-level gasoline-ethanol blend.
3	What makes a diesel engine fuel efficient?	c	a gas combustion technology and homogeneous charge compression ignition .
4	What is E 85 fuel?	d	40 percent range efficiency.
5	What advances make the diesel engine performance superior to the gas engine?	e	improvements in electronics

1	2	3	4	5

Exercise 6. Say which engine is considered to be more competitive and give reasons

Use the following:

To my mind	Diesel engine	. is /is not competitive in automobile manufacturing	because
In my opinion	Gasoline engine	will dominate / won’t dominate	as

1. its higher compression ratios and lean burn combustion provide high efficiency.

2.its average thermodynamic efficiency is 15 percent better.

3. its pricey after-treatment system crimps (снижает) efficiency.

4. its ethanol-boosted concept makes it possible to achieve thermal efficiency .

5. we see incremental improvements in hardware such as independent cylinder combustion control .

6. its fuel energy density is lower .

7.it still needs regular maintenance to keep it running.

8. its small ignition retard ( запаздывание) makes them more speedy.

9. it is more easily turbo-charged.

Exercise 7. Render the following text in English.

Engineering firm Ricardo—the company responsible for the seven-speed dual-clutch automated manual in the 1001-hp Bugatti Veyron—has somewhat loftier goals for ethanol. It’s working on a 3.2-liter V-6 engine that could replace a large turbo-diesel V-8 in a heavy-duty truck application. But it’s not as simple as adding boost. The engine internals have to be nearly as strong as those in a modern diesel and just about every piece in Ricardo’s running prototype has been swapped out for a heftier replacement.

The twin-turbo EBDI engine has a 10.5:1 compression ratio and uses two air-to-gas EGR coolers to chill the high-pressure charge, improve thermal efficiency, and to ensure there’s no overfueling of the engine under high boost. Moreover, there are other factors in play. As GM's Grebe points out, diesel fuel contains about 14 percent more energy by volume than gasoline. This gives compression-ignition engines a significant edge in fuel economy, as opposed to thermal efficiency. Of course, everything will change if and when spark-ignited engines switch to more energy-dense fuels. This race is far from over. (1120 characters)

Exercise8. Express your opinion about probability /improbability of different types of engine in the future.

I think	diesel engines	look very hopeful	As
I don’t think	gasoline engines	don’t look hopeful	For
	turbocharged engines		Because
	hybrid electric vehicles		because of

The following items will help you:

a. better fuel economy.

b. they are non -toxic, non-explosive and practically noiseless.

c. they are much noisier and tend to vibrate.

d. improved after-treatment systems.

e. they are environmentally unfriendly.

f. they are more economical and environmentally friendly.

g. longer engine life.

h. their efficiency is much higher.

i. they can run on an alternative fuel (biodiesel or vegetable oil)..

j. the improvements in electronics and materials.

k. they are more powerful and reliable.

l. they are heavy and occupy much space.

m. long failure-free operation.

n. limited charging extra weight and high maintenance cost .

o. they are easier to maintain

Exercise 9. Topics for reports:

1. The engine of the future.

2. A great future is in store for electrical cars.

3. Transport and the Environment.

4. Hydrogen engine.