[QUOTE=Ethan]do you make any attempt to match revs on your downshifts? a little blip of the throttle to match that 1000rpm jump as you flick into the lower gear.[QUOTE=Ethan]

I don't think this makes any sense. On an automatic, blipping the throttle doesn't match revs because the engine and transmission aren't diengaged like in a manual with the clutch depressed.

And like many people say, by constantly shifting your auto you are increasing wear on transmissions (several thousand $ to replace) to extend life of $50 brake pads. That said, I will manually shift my 300E sometimes because in D it is too slow to downshift and doesn't hold gear long enough when you are trying to drive quickly in city traffic (where you can't just floor it in each gear because you have to keep slowing down and speeding up to go around slower cars). My other car (Porsche) is a manual and my 300E is the first auto trans car I've owned so it is just a habit.

Get yourself a first gear start kit intsalled.

As far as an automatic goes, my limited opinion is that you're not adding much wear to the transmission itself but the shift linkage is the big additional wear point.

As far as engine braking goes, its a matter of cost, brakes are cheaper (and easier to work on) than engines/transmissions. Another view is I can periodically change brakes in an evening without being without a car, but engine/transmission work is usually a lifestyle change.

[QUOTE=schumi][QUOTE=Ethan]do you make any attempt to match revs on your downshifts? a little blip of the throttle to match that 1000rpm jump as you flick into the lower gear.[QUOTE=Ethan]

I don't think this makes any sense. On an automatic, blipping the throttle doesn't match revs because the engine and transmission aren't diengaged like in a manual with the clutch depressed.


My reply, Do a test, drive in fourth gear at 50mph, while maintaing that speed shift into third gear, what happens?

In my car the engine revs jump approximately 1000rpm.

in my 722.6 transmission the gear changes in 4,3,2,1 are transmitted elwctronically.

Now let me quote from Vic Elford's Porsche Driving book page 101
"Heel-and-toe Shifting with Tiptronic"
many of you who now drive 911's or 968's with the Tiptronic transmission are probably wondering if you can apply the same technique -i.e heel and toe of a manual transmission.- The answer is yes.
You already know that when changing up you can do so at full throttle with just a tip forward of the gear lever so that there is no lost time in acceleration. When you are changing down you will find that you can actually feel the electronic contact as you "tip" the gear lever backward. The "blip" should be done at precisely that moment to balance engine and transmission speed. It mght take a little time to develop the feel for that electronic contact because it is very delicate, but it is there." end of quote

now that I have quoted, I used to drive a 1991 911 Carrera 2 tiptronic where I learned the technique and it works on the Mercedes box as well as the four speed ZF Porsche unit.

As far as mechanical sympathy and wear, you can reduce speed every time the steering wheel is turned to minimize tire wear, never start the engine when it has been sitting in sub-freezing ambient temperatures. Figure out BMEP - brake mean effective pressure and fuel consumption effective usage and only run the engine at that derived rpm.
But the great thing about Mercedes is they cruise at speed like no other, and now that some of these cars (New SLK 350) handle like a Porsche Boxster and are built much better, if you know the pros and cons to enthusiastic driving then have fun.

Do you buy a Ferrari F40 and not flog it? a little to much excitement a missed shift, a spin, a few over revs.

What does your manual say?

Mine says don't do it.

[QUOTE=Ethan][QUOTE=schumi][QUOTE=Ethan]do you make any attempt to match revs on your downshifts? a little blip of the throttle to match that 1000rpm jump as you flick into the lower gear.[QUOTE=Ethan]

I don't think this makes any sense. On an automatic, blipping the throttle doesn't match revs because the engine and transmission aren't diengaged like in a manual with the clutch depressed.


My reply, Do a test, drive in fourth gear at 50mph, while maintaing that speed shift into third gear, what happens?

In my car the engine revs jump approximately 1000rpm.

QUOTE]

Of course the revs will increase because of the different gear ratios between the two gears. With a manual trans you blip the thottle on downshift so that when the clutch reengages, the engine is already turning at the speed it will be turning for given road speed in the lower gear so there is no jerk as the engine comes up to speed. I don't think the printiple applies in an automatic, which lack a clutch between the engine and trans (it does have clutches w/in the trans). But I haven't driven a porsche with steptronic (because I think automatics in porsches are a tool of Satan), and I know the last Panorama one article describes various shifting techniques for use with them.

An interesting question. I've done this for 3 years and the car is fine with it. However, I don't do it just for slowing down approaching, say, a light.. I use it more for engine braking. Particularly when approaching a bend at speed, wanting to go through the bend in that gear without the box pointlessly changing up, and accelerating out of it in that gear.


Essentially the same as a modern button-operated auto then, but with a lever instead.


It is not for everybody though.. if it feels right doing it, and you can do it well, it is very effective and nearly as good (in some cases, better) than a button-activated tiptronic/steptronic automatic.

For those that don't understand what I'm talking about, well, it wouldn't seem right to you, would it! ;)

Likewise bringing the revs up when changing down.. the abillity is there, and gels very nicely when it works.

I believe the Mercedes engineers designed all this into the cars (it wasn't sometimes referred to as the best automatic in the world for nothing). :)

As for the longevity.. changing down without bringing up the revs produces quite a jolt, which can't be good..!


peace

Russ

Schumi,

You know that you don't need to use the clutch on a heel and toe downshift in a manual transmission, particularly a crash box.

With a synchro manual box a double de-clutch isn't even necessary. I do a single de-clutch on newer synchromesh units, if a synchro gearbox is going in for a rebuild I'll many times go clutchless

As for the blip on a Mercedes automatic, I can manually downshift my automatic where the engagement is imperceptible as compared to not using a blip on the same shift where the engagement of the downshift balks.

The only issue for me on blipping an automatic downshift on my car is that because of the pedal configuration left foot braking works best. I wear a size 10-1/2 or 11 shoe and no matter how I position myself I find the height and distance between the two pedals too far apart.

I blip and it feels GREAT! I drove one of those new Bently monsters. When you push the button to downshift, the computer blips the engine for you right as the downshift occurs. I've driven several cars with the triptronic auto/stick thing, and, for me personally, the MB gated shifter is MUCh more intuitive for real world driving. The C230 is the first car that I have personally owened. As a new driver I always drove my paretnts' stick shift cars. Then my wife and I inherited her grandmother's stick shift Geo. For where we live, though, a standard transmission is just not practical. That being said, I just can't stand the feeling of coming out of a corner in too high a gear. The gated auto shifter, blending the benefits of a standard and automatic, is the best thing that ever happened to a transmission. Does anyone have proof of an MB auto box failing due to semi-manual shifting? I bet that holding 3rd or 4th for around town driving acutally saves me thousands of shifts from 5 to 4 or 5 to 3. The bottom line is I just don't care, it feels right to me. If the transmission isn't designed to work this way, then I don't want it. Good luck to everyone and enjoy!

[QUOTE=Michael Kerley]blah[QUOTE]

I agree Michael.. I also think that its effectiveness is why certain Japanese and French manufacturers have copied the shift gate.

The more mechanical feel is, in some ways, more satisfying and more like a true manual than newer electronically controlled automatics, with which you never feel like you're doing anything directly.

Russ