Carzzz

Vehicle: C250 4-matic Sport 7G (M272 2.5L V6 201hp)
Condition: well past Break-in period, feed only with Premium Fuel (91 Octane).

I know this car never feel fast, but adequate for my day-to-day drive.

Recently give a run from 0-100km/hr on a vitually unnoticable incline.

"Sport" Mode, vehicle warmed up, and shifts @ 6500rpm; temperature around 20C; I was the only person in the car (weight less than 150lb), and with only half tank of gas

It tooks 10.2 sec!
MB Canada rate it as 8.4 sec from 0-100km/hr

Is there something wrong with my vehicle? It is like 2 sec slower than mb stated

jctevere

I can't explain as to why. But I can confirm that my c300 has been doing something similar. At first I felt my c300 was faster than what MB claims, but as of late I have been less than impressed. In fact, the difference between how my vehicle used to be, versus how it is now, is like night and day.

A while back I remember someone explaining a phenomenon where over time the vehicle's performance degrades and something must be done to fix it. Spark plugs possibly?

BlackjackM

How did you time it?

Carzzz

It was recorded through camera phone. Then uses regular stop watch to verify!

zankok

its normal to be slower than it claimed, but full 2 second seems odd
i have c230 RWD and i feed it with 97 every time but never timed it, but it seems pretty fast to me
the 2.5 litre is actually very similar to the c300 ones hence the similarity in performance, the cylinder dimensions r the same, its just the travel that makes the displacement less, so essentially if we replace the crank we will get the same 3 litre v6, but its not like the performance of c300 really makes that much different to be worth the change, i suspect it is slightly torquier

Carsy

In Australia 91 is not Premium fuel , 92 is our regular then 95 mid range & 98 premium.I did not think your US engines would run at optimum specs on that 91 fuel .

An ever so slight upgrade will make a lot of difference to your time. Try the timed run on a perfectly flat stretch of road.

BlackjackM

I also think that your method of timing may be part of the problem. See if you can borrow someone's G-Tech if you don't have one. They're not the be all end all, but they are pretty accurate. I think there's an iPhone app that will give you 0-60 times as well.

keith100

91 in North America is premium, and equal to the 95RON available in Europe. Maybe Australia uses the Euro method of calculation, hence 92 being your regular and about the same as our 87 ?

As to the speed, MB may hit 0-60 in a little more brutal fashion than owners would care to use?

Cheers

Carzzz

Tested a few W204 with 2.5L V6 never pulls hard... I have a van, rated about 9 sec from 0-100km/hr, that pulls noticeable harder than the benz (2.5L V6 of course)
I guess my feeling is right!
I hope my car has no mechanical issue that causes almost 2 seconds slower than what mb rated...

Something interesting is that MB rated 2.5L V6 with or without 4-matic from 0-100km/hr in 8.4 sec

waiszeto

Hey bro .. i have the same car as you Shifting the gear at 6500 rpm does not give the best performance in acceleration. From what i remember, try shift ur gear one at 4500, gear two at 5000.... you might see difference in acceleration from 0-100. RMB shift your car at 6500 rpm will not get u the max HP, but it will get u the max torque! That why plp will down shift before they enter to the corner or turn, so their car can keep in very high RPM. Once they exit the corner, they will up shift to make the short boost in order to maintain the car at the high speed. By the way, you might want to switch from 91 to 94 performance fuel, which offer in Sunoco and most of the petro Canada.

lithium332

Lol that is pretty strange. My 0-60 time is around 7.2 secs. 10.2 seconds is definitely not normal.

Edit: I was in sport mode.

mr inkredibul

He was shifting at 6,500. I would have to think he is WAY outside the powerband. Let the car shift for you. It's smarter than you.

Carzzz

Engine Family: M272
2.5L V6
Engine Compression: 11.4:1
201 hp @ 6100rpm and 181 lb-ft of torque from 2900-5500rpm
It shifts @ Redline 6500rpm

Shifting around 6k-6.5k makes sense

mr inkredibul

You were already out of the power band at 6.5K Since you have the 7G, I can guarantee you that the fastest 0-60 time will come when you leave it in auto mode and put it in sport mode.

Carzzz

Just uploaded...
http://www.youtube.com/watch?v=QH5JxG9nMYg

I forgot to set a higher resolution on my last attempt

It was in both "S" mode and auto mode!

waiszeto

After watched ur video, i got few questions to ask u...

1) Did u kick down? In the video, it seems u have a weak start
2) Did u check ur tire pressure? Make sure it 30 in the front and 35 in the bak. Trust me, tire pressure do make the difference!
3) Did ur car equip with performance tire or just normal tire? This makes the difference TOO!
4) Did you turn off the heat and air condition?

Carzzz

1) I did... It is from a dead stop. For some odd reasons, this car is restricted (electronic protected) from doing hard launch. Even if you mash the paddle to the Floor after the "click"/"Kick down", it still takes off lazily and then pick up.
2) Tires pressures were right (at spec)
3) Stock wheels and Conti tires: 225/45R17 front and 245/40R17 rear
4) No a/c, no heat, or not even fan