Just curious as both have the same engine, same HP/Torque numbers but for some reason the C230 sedan for '04 gets 23/30 and the '05 gets 24/32. Any clues as to what they did and can it be retrofitted to the older motors?

hmm, i didnt notice that. maybe they tweeked with the engine some!

Are the numbers for Auto or stick?
The gearing could have changed and/or the ECU on an Auto transmission.

I asked the dealer two days ago this very same question. He said that they lightened the car. But come on, unless they shed 300 lbs by changing the dash I don't know how they got 2 mpg more. I thought at first with the change of the shift linkage on the manual that had something to do with it, but no. 32 mpg is indeed on the manuals and the automatics. Seems, though, that I read somewhere where the front bearings were changed, I can't remember where I read it, but perhaps that has something to do with it.

What is everyone averaging in mileage for their 2004's and 2005's, sedans and coupes?

I know that while on my '02 I can get 32 mpg at a steady state 72 mph, alone in the car, over a 50 mile trip, that's unrealistic. On a real 500 mile trip I get about 28 mpg. How much more can I expect on a real road trip with passengers, luggage and a more realistic 80 mph with the 1.8L motor.

As for the 04 vs. 05, the rear ratio is advertised the same at 3.46:1. The HP/Torque numbers are the same. Automatic or manual, same 32 mpg hwy. Drove both back to back and engine wise they were the same although the 05 rides much harsher.

In 2003 when I got my Coupe, the automatic was rated one ot two miles better highway than the stick!

I think the government may have adjusted the test cycle, so that the national average is at least above 1980

My 2003 coupe with my wife and I and luggage on a 350+ mile trip to see the family while travelling at 75-80 MPH gets 32 MPG consistently. I do not baby it while doing this and we are travelling through lovely PA and NY, through the mountains non the less and I still manage to get that. While going between 65-90 MPH all the way and flooring it quite often. As well as a few downshifts to 4th when people **** me off and I wish to flog it by them.

What about the tranny? A minor/slight change can affect the mpg either way.

i avg. about 25mpg total. thats a coo between city and hwy driving.

I avg 27mpg in my Sedan, 80% Highway 20% Stop & Go.

improved aerodynamic because it has the AMG kit