kaku

For those with manuals, how often do you shift to 6? and at what speed are you shifting at? Have you noticed any impact on gas/mpg between 5th/6th?

I'm usually cruising at 70-80 mph but stay on 5th - I like staying in the "power band" where I can accelerate quickly if need be.

jaymoney92

Dont have a 6 speed yet
but how are you liking your c300 6speed?

C300Sport

It really varies depending on how fast I am accelerating. If I am just poking along in traffic, I will shift into 6th at around 40 mph as long as it is fairly flat with no real need to accelerate quickly. If I am on an onramp getting up to speed, I usually shift around 60 mph.
At highway speeds, I would always keep it in 6th and shift as needed to catch a gap in traffic, etc.
I can't really help you with what sort of MPG difference 5th to 6th makes as I have always driven like this. Maybe get to a steady 70MPH in 5th and reset your MPG gauge and run for a few miles and then do the same in 6th. You may have to do it a few times to get a reliable idea due to the tremendous amount of variables.

Sportstick

I run up to about 3,000-4,000 rpm for most routine shifts, higher when wanting to "hurry", because I like the feel, but also use 6th all the time. Anytime cruising at or above 45mph, 6th is just fine for extended periods. The engine has a nice flat torque curve and moderate acceleration is available. Of course, a reflexive downshift is about a 3/4 second event if needed, even double-clutching, and part of the entertainment factor. I have not done the math, but there will be a difference in fuel economy at different rpms...its just a matter of how much and whether it matters to you. Of course, if you are just on a highway or even a moderate access road at 45 or more, good conditions, etc. why run the engine at higher rpm than needed at that moment, particularly if you bought this car for the long run?

Remember, gears add weight and cost. An MB Powertrain Engineer approved having 6th for a reason, when they could have left it out and gotten a gold star on their personnel review for weight and cost management. So, use it and reap the benefit!

kaku

wow, either you must be shifting every 5-7 miles or you're skipping gears. but 6th gear @ 40 mph is just way too early. i'm surprise that the car will even pull at low of an rpm. you must not have any passengers=)

Sportstick

6th gear at 40mph is early during an acceleration. But, if you are in a 40mph zone and cruising at 40mph, shifting up through the gears to 6th works well and there's more than adequate torque to hold it there.

Spec_Davis

i use the 6 spd on the Highway

C300Kid

Theres really no reason to stay in 5th when cruising at highway speeds..it only helps during acceleration.

i usually pop it into 6th once im at a steady speed..be it 50mph or 90mph

Derspeed

Only on the highway and over 55mph. I agree with Sportstick. The speed range in 6th gear is nice.