rb23lb

So I had a 2009 c300 loaner car and I noticed that while it was slower, it was more responsive on the throttle than my 2008 c350.

After getting my 2008 c350 back, I played with the gears a bit to see if I could receive similar results...

Here is what I noticed:

Cruising the highway at 70 mph in "D" or standard automatic mode, the RPMs are right about 1900-2000.

Cruising the highway a 70 mph in "D6" or the top gear of the semi-automatic mode, the RPMs are right about 2200-2300.

In "D6", I noticed the car was quicker to accelerate to 75 when I hit the gass than in "D".

This doesn't make sense though really, because in both cases, the car is in 6th gear, right?

I think that maybe when in "D6" semi automatic mode, the car's ECU is more responsive and quicker to give gas???

What do you guys think? Anybody else notice the difference in RPM's between the two 6th gear methods????

jstaneff

Are you sure? I think that the auto will settle into 7th whenever it can, to save fuel. If you are cruising at 70 in D and push the shifter left, does it then say D6? If so, you had been in 7th. Had you been in 6th, it would now say D5.

joshg1001

no, dont forget this car has 7 speeds for automatic.

so when your in D, your really on 7th while cruising on the freeway. thats why when you move the shifter to the right to do the manual mode, it goes to 6th...

rb23lb

doh! i forgot! but I guess the reason I forgot, was that because you cannot go into "D7" and can only go to "D6" in semi automatic???

rb23lb

thanks for clearing this up...

Please DELETE this thread MOD

joshg1001

lol no you can still go into 7th. the car automatically puts itself into the gear that is infront of the one your actually in. say your in 5th, it will go into 4th when you put it into manual mode. if your in 7th, then it puts it into 6th. you can then move the shifter to the right to shift up when needed, all the way up to 7th

Bobby204

Took me a while to figure out the D=D7 thing...

rb23lb

nah, there is no D7 I am pretty sure.... "D" = D7

D6 is the highest it goes numerically

joshg1001

hmm interesting. i could have sworn ive seen a D7... will check again

RLE

You didn't. When there is a gear number displayed, that simply indicates the highest gear the trans will upshift to. With no number shown, it will progress to 7th gear. BTW, if you are poking along at 120mph, you cannot downshift to a gear that will over rev the engine no matter what you do with the gear lever.

joshg1001

yes i understand that part. what we are discussing is whether or not you can manually shift it into 7th gear, and not D. or if D represents 7th gear.

GateKeeper

D represents 7th gear

I have never seen D7

when in top gear and I move it one down it will show D6, move it up it will show D.....

just a side note - if your in some of the lower gears, 2-3-4 and so on and you move the shift lever to the right and hold it, it will go to the top most gear "D" automatically...which will put you back in auto shift mode once again....

kevink2

As was said, semi-auto sets the highest gear you can be at. If you are in C or S mode, those aspects will be maintained.

Manually shift up, and you will see D5, D6, then just D (7th) as there is no higher gear after that, so plain old D is the highest gear, and semi-auto becomes same as full automatic mode.

RLE

You cannot force a shift directly to 7th gear from any gear unless it's already in 6th and car speed will allow 7th. As I said before, D just allows all gears, when the trans is ready.

You thought you were in charge, didn't you?

joshg1001

^^ that was never our question. the question was whether theres such a thing after 6th gear in the manual mode.

as i shifting from 1st to 2nd, to 3rd, to 4th, to 5th, to 6th and then finally to 7th. the other scenario is if 6th goes to D. that is all.

e1000

1, 2, 3, 4, 5, 6, D.

The numbers represent the highest allowed gear for the transmission. So, if you select 4, it will change from 1st all the way up to 4th as you accelerate and then hold 4th for as long as possible. Once you hit redline, the car will force an upshift.

Holding the shift lever to the left for 2 seconds will select the lowest possible gear for that given speed. Holding the shift lever to the right for 2 seconds will put you in D.

You cannot select 7, it is D.

ococ

I have a c350 with advanced agillity control and if i put that to on and the transmission manually with using the paddles i have 1,2,3,4,5,6,7 in the screen.

mac911

Yes, you are also correct.

However, in the USA, we don't have full manual capability, so that is why we never see 7. We get a dumbed down car here.

kevink2

"D" being displayed really has 2 meanings. It mainly means you are in automatic mode, and could be in any of the 7 gears.

It also means, when you have beed upshifting in manual mode, that you have gone from 6th gear (D6) to 7th gear (D) with that last shift, and ( if you don't bump the shift knob again) you have returned to automatic mode.