Hoovey689

iTrader: (16)

Mercedes-Benz: U.S. fuel too dirty for next-gen efficient engines

The newest gasoline engines from Mercedes-Benz feature cutting-edge lean-burn technology that leads to fewer harmful emissions and a 10 percent improvement in fuel economy. Well, the new engine tech, which requires a much leaner fuel-to-air ratio, is making its way into many mills, but apparently not the ones destined for these United States.

Ward's Automotive quotes Daimler powertrain development vice president Bernhard Heil as saying that the gasoline in the U.S. contains sulfur at the rate of 95 parts-per-million; about twice as much as can be tolerated by the new engines. The problem? Excess sulfur apparently clogs the nitrogen oxide-capturing traps.

So, is the U.S. the only country lagging behind Europe in removing sulfur from its gasoline supply? Far from it. Heil points out that the gasoline in Africa and many areas of Asia also contain too much sulfur for the lean engines. The first engine to feature the technology is the direct-injected 3.5-liter V6 destined for the C350 sport sedan and the SLK roadster seen above. The 302-horsepower mill will not (obviously) utilize lean-burn tech here in the U.S.

http://www.autoblog.com/2011/03/17/m...icient-engine/

Och

iTrader: (3)

Are they talking about petrol or diesel?

I thought petrol didnt have issues with sulfur or NOX?

RXSF

this was their excuse like 5 years ago. So...we still get the upgraded 3.5 but no clean burning tech?

DFGeneer

Och, the lean burn mode produces NOx - the fuel/air ratio is far below the stochiometric (where all the carbon from the fuel bonds with all the oxgen from the air) hence excessive ammounts of oxigen in the chamber some of which bonds with nitrogen from air.

The way they wrote the first sentence seems like Lean Burn = fewer harmful emissions. But this is true only for unburnt hydrocarbons.
In case of NOx, it is exactly the opposite - hence the need for NOx-capturing traps that get clogged by the higher sulfur content.

4TehNguyen

iTrader: (1)

so great they want to make our gas more expensive by wanting to do additional refining to remove more sulfur from the fuel

spwolf

sure they do... if you start using high pressure DI then you are going to have same problems with it as in diesels, they need clean fuel.

Blackraven

What the guy from Daimler says has some merit which cannot be discounted....

In the end, you would have a trade-off: better and more powerful engines but requiring higher quality and cleaner fuel OR 'restricted' engines that can run even on the ****tiest quality of fuel known to man.

This is the reason why Lexus does not sell cars with Direct Injection engines (D-4S technology) in the Middle East & some parts of Asia (like in the Philippines).

Jewcano

iTrader: (4)

Question is, what does this do for the people who already have cars who aren't thinking about upgrading to a benz? If it jacked up gas prices and didn't benefit the millions of other non-benz drivers, then I think as the majority, we wouldn't want more refinement if we are going to only suffer because of it. Benz can take it's 'special' engines and keep em in Europe for all I care.

bad co

I remember that VW threatened to pull its TDi car's off of the U.S market because the fuel was so bad. Now all diesel is ultra low sulfur and manufactures like MB BMW and VW are bringing over more diesel options. U.S has some of the crappiest fuel. 91 octane is the highest rated fuel in a lot of U.S cities. While 91 is the lowest rated in most European Cities.

bad co

Refining is not the problem, its the lack of additives/detergents that gets you.

werewolf

Gas is subsidized in the US although state taxes claw a fair amount back

Jewcano

iTrader: (4)

Well if they would like to pay for more detergents in fuel, by all means they should foot the bill for it. The millions of drivers here who don't drive those benz's shouldn't have to pay more at the pump so that MB can bring cars over here.

bad co

No one would force you to buy the 95 octane, stick to your 89. While I buy my 95.

Jewcano

iTrader: (4)

We don't have 89 around this area, as far as I know. All we have is 87, 91, 93. I'll stick to 93, my point is that I wouldn't want companies who sell gas to bump up the prices because they would have to add more 'detergents'. Are you saying that only prices for the top octane would change? And where did you get 95 octane?

DustinV

Correct.

91 is the lowest. The other choices are 95 and 98 octane and some gas stations will offer some type of "special performance fuel" (Shell notably), which really is just a bunch of marketing hype.