I have a question about all the new cars coming out with Direct Injection engines. I was reading a few articles which imply that we are not getting the full benefit of DI in the USA becuase our fuel is too dirty (too much sulphur?). Is this true? Apparently our DI engines do perform a little better, but we are not getting the full power or efficiency benefit that Eurpoeans enjoy with cleaner but more expensive fuel? For example, Audi uses "Fuel Stratified Injection" (FSI) on european models, but in the US, it is called "Fuel Straight Injection" (FSI). Apparently, they can lean the fuel out even more on european FSI engines than on US FSI engines purely because of the fuel used. The same trend goes for DI engines from GM, Toyota, Mazda, etc.

Someday, I assume our fuel will get cleaned up. When that happens, will all the older DI cars be able to take full advantage of the better fuel with updated software? Or does the low quality fuel in the US actually dictate unique physical hardware that is different from the DI systems used in Europe?

So... given two cars with nearly the same current fuel economy, one DI and one non-DI, is it worth getting the car with the DI engine because it can be made more efficient/powerful later on with software, where the non-DI engine will be stuck at the same level?

 

US (and Australian fuel) is high in sulfur content... which is why you should opt for the best PULP fuel if you want maximum benefit from the DI engine.

The latest generation DI turbo diesel engines rely on low sulfur diesel for similar reasons. It wasn't until last year that the federal government in Australia mandated that only the low sulfur diesel may be sold throughout fuel outlets, opening the path to the new generation engines that Europeans have enjoyed for years.

 

So when the US finally gets low sulphur gasoline, will the older DI gas engines be able to "adjust" to the better fuel and get better fuel economy? Or will upgrades be necessary to older DI gas engines to get the maximum benefit?

 

"Straitified" (lean burn) combustion operation is a no-no in the US - our EPA regs favor low emissions over low fuel consumption, and lean-burn operation can cause a dramatic increase in NOx emissions. European clean-air laws take a different approach, and since CO2 is classified as a pollutant over there, the trade-off between economy and emissions is balanced a bit differently, with less attention paid to NOx.

It's possible that a NOx trap could be fitted to a lean-burn engine, but by that time, the system cost is probably approaching that of a diesel. It's also possible that one could recalibrate their engine management system to allow lean-burn operation, but that would be a fairly major violation of EPA clean-air regulations.

 

How lean is lean with straitified? The Solstice/Sky DFI engine will go 32:1, are we talking leaner than that?

 

That's pretty lean. The main question is how much time can you spend at that A/F ratio?

Normally, U.S. engines run at 14.7:1, where the 3-way catalyst can reduce NOx. If you run leaner than that (whether it's 16:1 or 32:1), then the cat doesn't work, and you get engine-out NOx emissions. There are new technologies for NOx control in oxygen-poor environments. The Bluetec system is one of them. However, they are more expensive and probably not as effective as the regular cat-con. It's a lot easier to meet European NOx regulations than the American regs. I believe that we now run low sulphur gasoline in the U.S., but you still have to ask yourself how much more benefit is there to be had by running lean versus the cost of the NOx control.

One reason U.S. gasoline had more sulphur is that we get more oil from places like Venezuela, which needs much more refining to remove the sulphur than oil from the Persian Gulf. At least I remember reading that somewhere....

 

2007 emissions diesel engines require low sulfur fuel to prevent fouling of the particulate traps (aka DPF - diesel particulate filter), which is a new exhaust aftertreatment device added to these engines.

 

you get most of your oil from Canada I think most of it is refined there too.

http://www.eia.doe.gov/pub/oil_gas/p...nt/import.html

 

And their purpose is sinister I tell you!

 

ROFL!!! Muuhahahaha!! Your onto us

 

Yeah, i mean, it's not like anyone around here would ever consider touching their tune, especially in a manner that was inconsistent with federal emmisions regulations, and certainly never to attempt to defeat on board diagnostics. Is such a thing even possible

 

 

And the stuff from Canada certainly isn't light and sweet like the Saudi oil is.

In any case, the gist is that oil that the U.S. gets has more sulphur than oil that Europe gets, so it takes more refining to remove it.

Regarding refineries, I don't think finished product is shipped all over. Most California gasoline is refined in California, with our unique blend. A couple of years ago when a number of California refineries had trouble at the same time, some refinery in Texas brewed a bunch of California gasoline, but it took a while to get here, as it had to be shipped through the Panama canal.