240D Top Speed ? - Page 2 - PeachParts Mercedes-Benz Forum

Eberhard Weilke · #16 05-25-2002, 04:17 AM

...they actually kept up pretty well, since they had a 102 liters fuel tank and could skip every second fuel stop

The crowd was amazed by the vehicle and yelled "Taxi, Taxi" every time they passed by the Hazenbach

Kind regards
Eberhard

#17 05-25-2002, 04:19 AM

Are there any W123 taxi's still in use there? If so, what are they? 200, 220, 240 or 300D's? I would imagine they are all manual trans cars with manual everything.

Eberhard Weilke · #18 05-25-2002, 08:16 AM

...still some 123 Taxis around. All kinds of engines (240 D, 200 D, 300 D), manual and auto.

There is even a W 115 still alive in Cologne, they used to have a W 111 taxi until it had a head on crash last year.

It is interesting, that cab drivers still don't like the W 210 and keep the resale value of the W 124 pretty high.

Here in Esslingen there is a fleet of long term test cars of Daimler Chrysler. It is nice to choose at the taxi stand between a W 220, W 211, S 203 and several A-Classes, normal and long wheelbase.

Kind regards
Eberhard

#19 05-25-2002, 11:38 PM

This is to "Gilly" and "Eberhard Weilke" - let us then assume you are all correct. Let us also assume that a Michigan State Police Laser Gun is also inaccurate by 7% - Let us also assume that not only Ford, but also a GM car with Digital speedometer is also Incorrect. Then all your theories would then be Correct!

But, now, if we were to consider a Digital speedometer on both a GM and Ford car as close to accurate within even 2 mph - that still states that my speedometer is correct - Not to mention the speeding ticket I damn near got!

But then I am only a young 49 year old with only 1.5 million miles under my belt in a Semi.

So, now as to the lower compression - please explain to me why a RC diesel engine turns up to 24,500 rpm's with a compression ratio of 25:1 to as high as 32:1? But I suppose that is LOW COMPRESSION thereby allowing that small 1-5 cylinder(s) engine to turn such high rpm's.
Explain the Detroit 2 Stroke engine to me too! Let's not forget the International engines that turn over 4500 rpm's! (DT series).

oops, I hope I haven't just thrown your theories out the window!
Please also explain to me why they use adjustable Torque wrenches on Areo Piston & Jet propelled engines. We all know they don't turn high rpm's and are not a very critical engine, right?

I read over your flimsy excuses. Even accounting the over-age on the optimism of the speedo - this doesn't take into account a Laser gun or a GM or Ford Digital speedo, does it? And yes, I would say after running for a 12.5 mile stretch and have very consistant time per mile, I was almost beginning to think that the 90+ mph I was seeing was close to an accurate reading.
Oh, did I also forget the mention the newer Chevy 4x4 Suburban? But then GM is very optimistic on their speedometers, aren't they?

You all come up with big ideas and sophistocated theories to prove how it is not possible for a 23:1 compression ratio'd 65 hp 4 cylinder diesel to go faster than the rated speed.
I mean, Come on now, Mercedes wouldn't ever be wrong, Mercedes wouldn't ever have a fluke car that is a bit faster than the average Bear! You all are so pathetic!

adiaw83 · #20 05-26-2002, 02:10 AM

there are tons of 123 taxis all over senegal i west africa.

Holson Adi · #21 05-26-2002, 02:30 AM

I wonder if I could ask a cop to see if I am indeed running at 60mph when the speedometer says 60mph.

#22 05-26-2002, 05:36 AM

Just because a speedometer is digital does not make it accurate.

Police cars have "certified calibration" speedometers, it says it right on the face. They are calibrated every month, or every few months and it gets a certificate. This is so they are able to clock your speed accurately without the use of radar, known as "pacing". Ford does not make a digital speedometer in thier police interceptor, but the old chevy caprice 9C1 did have the digital speedo.

I just passed one of those radar signs today where it says "you are doing xx in a 25", and when my 300SDL's speedo said 40 the sign said 38.. I think that radar gun is more accurate than my old speedo with a 1/4 million miles on it.

W123 speedos are usually pretty innacurate. Every single one I had was optimisitc by 5% to 10%. They are mechanical, where as the W126's speedo is electric and more accurate as it ages.

Gilly · #23 05-26-2002, 09:51 AM

240D
OK OK! Congratulations, you definitely have the absolute fastest, ahem, 240 Diesel, at 90 stinkin miles per hour, that I personally have EVER heard of. 90, hard to believe, isn't it. MAN.
Gilly
ps: whoa, 90, awesome. Wax job? 92, minimum.

Eberhard Weilke · #24 05-26-2002, 06:35 PM

Benz 240 D, I never said that your 240 D won’t run 90 or even more.

As I posted earlier: Mercedes tend to be rather conservative with the figures they posted for top speed. Off course a good running engine might go faster. Your car might be one of those. Well, believe it or not: It also pretty much makes no difference if you are alone in the car or with two, three or four adults. It also make no difference if you have a euro- or US-specs car. The US car might have a slightly bigger drag coefficient, the rest of the car (engine, gearbox, rear axle ratio) is pretty much the same.

BUT: I really only believe numbers which have been clocked in a reasonable procedure. A digital dial in any Ford or GM product gives by no means an accurate reading. The warning of a County Sheriff is definitely not an accurate reading. These funny speed signs in the cities “You are doing xxx mph” are not an accurate reading.

An actual reading is done with a calibrated speedometer. Here in Germany the VDO-Service can do that for you. The do-it-yourself method would be a speedometer which has been tested against the mile-markers at an Interstate with a car on cruise control (as I mentioned earlier it would be six minutes for 10 km at100 km/h)

Then we talk about facts.

It is also not theory, it is fact that a Diesel with lower compression can run faster. How come? The high compression is work which has be done by the engine. High compression is necessary to start even at the lowest temperature with a dead cold engine. The designers also took into consideration that the engine also will start after years of wear and tear.

If you set the compression ratio lower, (enough that the air is hot enough to ignite the injected fuel) you get more hp to the wheels. And please don’t compare that with any contemporary diesels for trucks and alike. The construction of the OM 617 can be traced directly to the OM 621. We are talking about 1950’s technology.

Kind regards
Eberhard

p.s.: Since we started talking about facts: Do you have a compression test of your engine?

#25 05-27-2002, 05:15 AM

My 1974 W115 240D automatic is the real speed demon! It does a grand speed of 78 mph but you have to hold it wide open for at least 2 1/2 to 3 miles to attain that speed. 74 is easy, getting that extra 4 mph is the hard part!~ A bit of a wind not in your favor then you can forget anything over 74-75 mph! I swear a bicycle could beat it up to 20 mph! Pulling out into traffic takes real guts! And Bravery! And you hope the other person has good brakes!
That W123 240D will beat it with ease!
As for 50's technology, look at the Ford 7.3 Liter diesel, it was originally a International engine designed in the 50's and it is still basically the very exact same engine.
As for comparing truck engines to the car enine, it is Still The Same principal - a diesel engine is a diesel engine - it functions the exact same, irregarless whether it is in a car or stationary or in a truck or a dozer.
The basic function is still the same. Whether it is a 4 stoke or a 2 stoke, it still functions and worked the same way, and it doesn't matter if the diesel engine was designed in 1930 or 2002. It take Air and fuel and compression to make it work.

Gilly · #26 05-27-2002, 09:52 AM

Sure, sure, right again 240D, never been wrong yet. What possible difference is there between 2 stroke or 4 stroke, direct injection or pre-chamber method or common rail? None!
Only a trucker could make such astute observations and make it all seem so......hmmmm, I guess "simple" comes to mind. You just have a knack for reducing everything down to it's most basic terms. Crank turns, pistons go up and down, engine runs, what else matters? Nothing!
Gilly

Eberhard Weilke · #27 05-27-2002, 01:58 PM

...I have no doubt about that.

That's why this beauty easily turns 25.000 rpm.

All right, it runs on coal dust. But the principle is the same. Piston going up and down.

Kind regards
Eberhard

JimSmith · #28 05-27-2002, 04:27 PM

Another interesting thread.

Someone already mentioned this but I thought it might be worth examining it again.

The W123 car has the drag coeficient of a car designed before the gas crisis of the early 1970's, probably in excess of .40. Meaning it is pretty poor. If you make an inventory of where the engine's power on any car is going at the factory cited top speed, you will find the greatest bulk of it going to pushing air out of the way. To take a stock 240D engined W123 car to 92 mph would require 14% more power. I am reluctant to believe there are 14% swings in output capacity between cars coming off MB's production line. Maybe plus or minus 2 or 3% total, but not plus or minus 14%, or even plus 14% minus 0%.

However, if someone had a slightly lowered car, maybe undersized tires, aerodynamic hubcaps (not those Bundt cake alloys), no passenger side mirror, Euro headlamps, and got a 2 or 3% reduction in the drag coefficient, they might actually see a higher top speed by a few mph with an engine that was within the normal factory variations, although on the high end of the distribution.

One of the reasons the W126 and especially the W124 cars go to higher top speeds with the same (W126) or a slightly higher performing (W124) engine, is they have much better drag figures. My W210 E300D TurboDiesel feels like it will just keep accelerating past 120 mph. It likely will, but if it were a W123 body, going 120 mph would require over two and a half times the power of the 240D to make that speed. Cars like the W123 280E were capable of those speeds, but had engines that could pump out 185 horsepower. The W124 with that horsepower went nearly 145 mph.

The point is, a slight advantage in drag coefficient, like skinny tires and smooth hubcaps and so on, might get you the extra few mph that are being discussed. I think they will before I would believe someone has a stock 240D that has the output of a stock non-turbo 300D. So, Benz240D probably did see near 92 mph, but not just because his engine is so good. Jim

#29 05-27-2002, 07:41 PM

Good points Jim.

I am amazed at what a big deal this has turned into. Why would someone lie about the speed of their 20 year old car... to *other* enthusiasts?? Where is the logic in that? This guy has no reason to lie, what would be the point... All this second-guessing and hypothesis-construction is crazy!

I might *initially* suspect some "stretching of the truth" if this guy were bragging about a Volkswagen diesel or a Peugeot diesel

on this forum, but not a fellow Benz.

We're only talking about 90-something MPH here--that isn't so hard to believe.

-Joe

#30 05-27-2002, 07:47 PM

I posted a pic of the speedometer in my Peugeot TD touching 127 MPH as just a gag... It was really taken in another Peugeot 505, I just did it as a joke because even if my TD had enough power to reach 127, the engine would have long passed it 5000 RPM limiter!

The funny thing is that some people on this board were like "are you sure that isn't from your other car", etc... They saw right through it!

Yet the Peugeot forum people were trying to explain it "well maybe your timing was bumped up" or "Were you going down a hill?". I even had one guy email me wondering what I did to my car and how to replicate the modifications...

-Joe (funny guy) (not really)