Can you drive your car in "3"??? - PeachParts Mercedes-Benz Forum

mike690003 · #1 08-07-2003, 04:35 PM

Hello Board, I know a couple of people that drive their automatic MB's in the 3 position as opposed to "D". Mainly I see people in 190's and 300E's do this.

Does that have a negative effect on the tranny??

What is the top speed that you can drive in the 3 position??

Why drive in "3"???

Jackd · #2 08-07-2003, 09:07 PM

Look at your speedo. The are 3 sets of yellow marks.
I do not have the exact speed in front of me, but your should have 1 marks at about 25mph, 2 marks at about 45 mph, 3 marks at about 75mph. ( I could be a lttle off with those speeds).
JackD

mike690003 · #3 08-07-2003, 09:14 PM

What do they represent??

Will driving in "3" hurt my tranny???

DslBnz · #4 08-07-2003, 10:50 PM

I think Mercedes set an overspeed governor in all their cars so that you couldn't exceed the maximum engine speed when you are in any particular gear. My SDL (Believe it or not)is governed between 5200 - 5500. Not bad rev range for an oil-burner!

The marks on the speedometer

one mark 'first to second' *

two marks 'second to third' **

three marks 'third to fourth' ***

Third gear should take you up to 75mph and bounce off redline. Engine might kick back if you're accelerating too fast.

A little trick, of course, for all second gear starting Benz's. You can start out in first if you shift to '2' and back into 'D'. Or in the V8's, shift to 'B' and back.

william rogers · #5 08-07-2003, 11:27 PM

I regulary drive in third or 3 as we live in OR's Coastal mountains with lots of up and down curvy roads. My Euro 500 SE shifts into fourth between 135 and 140.though there arn't any places straight enough to try that little trick for witch I'm glad......
William Rogers........

tvpierce · #6 08-09-2003, 05:50 AM

My short commute to work each day is through country roads, then city streets -- and the speed limit is 35mph for both. I drive in 3rd gear for the entire trip. Reason being that at 35-40mph, 4th gear puts the engine at about 1500rpm -- too low, causing the engine to lug. (35-40 mph in 3rd puts me at about 2300rpm)It is a commonly held belief by members of this forum -- myself included -- that bogging down the engine causes carbon buildup on the valves, resulting in the need for the tried and true "italian tuneup".
The "italian tuneup" works great at removing carbon buildup. But if I can do something to keep the carbon from building up in the first place, then I will.

Jeff Pierce

Arthur Dalton · #7 08-09-2003, 09:23 AM

Of course you can ..
As Jeff P points out, you match the load to the gearing..
Stick drivers are aware of this eng/gearing Feel , and the auto option lets a driver get in this "Best for the Situation" range.
If one is not aware of the mechanics of engine loads and gearing,
the auto Drive Range is fine, but the Option is better for those with this Feel, for both engine effeciency and wear/tear .
I, for one , never use top range until my cars are warmed up....

#8 08-09-2003, 11:30 AM

One of the reasons MB 4-speed autos last so long is that fourth gear is actually a 1:1 ratio and there are NO turning gear sets. Therefore, there would be more wear driving in third gear simply because there would be turning gearsets that aren't there in fourth.

These MB 4-speed transmissions also do not hunt the right gear like lesser 3-speed plus overdrive transmissions used in American and Japanese cars.

Arthur Dalton · #9 08-09-2003, 11:50 AM

The transmission [ any transmission] wear I am talking about is
the main carrier bearings and shafts that take a beating when you are in the least effecient range for load.. moving part wear under appropriate load is nil in comparison ...ever see what an overdrive transmission tail-shaft bearing looks like when guys drive around town in high range?
The least wear is when the power is transferred within a range
requiring the least power ..