Starting a new thread from a spin-off discussion form this thread:

https://mbworld.org/forums/clk-class...c-problem.html

You are right - MBZ doesn't care to play the US government's games, and this is one of the many things that give me great respect for the company. Our government continues to put more and more restrictions on our automobiles. While I am all for improving technology to make cars safer, faster, more secure and efficient, I believe this should be played out in our open markets. Instead, the US government continues to require car manufacturers to add ever increasing safety and emissions control features that add weight and degrade performance, but then they also require ever increasing economy. Somehow, the US government believes it can legislate away the laws of physics and hasten advances in energy technology that the best and highest paid scientists in the world can't seem to attain.

The result is that we end up with a bunch of dull FWD appliances. But MBZ and other makes scoff at that idea. They continue to make revolutionary discoveries in safety and performance, and fuel economy but that "iron triangle" is a bit shallow on the fuel economy side, so instead of shortening the other sides to match,they pay the fines. Of course we as customers must absorb that cost, but at least that's our choice.

Sorry for the soapbox speech, but as a "car guy", it's something I am passionate about.

Did not know this. Agreed I respect the marque even more.

Good post Rudeney!

I recently rented a 2012 Dodge Grand Caravan. 4.0L engine with a 6 speed box. It has a user selectable "ECON" button that improved economy by 1.5 mpg, which is no doubt what is used in advertising and overall Chrysler CAFE figures.

The problem is that this 'mode' changes the shift points and torque convertor performance in such a negative way around town to make it undriveable - very rough downshifts, skipping gears etc.

Thankfully you can deselect this mode and have a normal transmission but pay the 1.5 mpg penalty (which I will gladly do)

I am sure the CAFE numbers use this "available" technology, even if the actual drivers don't.

Some new BMWs have a selectable Econ mode that actually shuts the engine off when you come to a stop. When you release the brake, it restarts the engine (hopefully before the guy behind you starts honking). This is one of the main fuel saving features of early hybrids. Porsche has this, too, but they added a feature that stops the engine at just he right stroke so as to minimize restart time and effort.

Another thing to remember about EPA fuel efficiency estimates is that they were revised beginning with MY2008 to use different tests that are supposed to reflect more real-world driving. This reduced the EPA mileage estimates for most vehicles. For example, the MY2007 CLK550 coupe was rated 16/23 but the MY2008 is 15/22. A 1MPG drop is not horrible. Just for fun, here are some other cars with no major changes between MY2007 and MY2008:

Toyota Camry LE (I4/AT): 24/33 to 21/31
Honda Civic LE Sedan (I4/AT): 30/40 to 25/36
Mercedes-Benz E350: 19/26 to 17/24
Mercedes-Benz S65: 13/20 to 11/17
Mercedes-Benz E350 BlueTEC: 27/37 to 23/32

All the new Blue Efficiency/BlueTec Mercs in SA have stop/go fitted. Seems the MBUSA is reluctant to bring them in.

MB has had stop/start in Canada since the first S400 hybrids, so probably four or so model years. It's currently available here on all the cars equipped with a V-6 or V-8.