Well I was skeptical on what the real top speed of my car was but I figured it was going to come down to gear limitations. I had a few calculations that made me think just below 140 but I found a good starightaway at around 2AM and went for it.... I was happy with the results.

This was done in my bone stock '86 300E with front intake scoup cut and pre-cats eliminated. Just thought I'd share with you other 300E owners for reference.

The pic was taken just after it bounced off the rev limiter:

__________________
-Kevin

Hi there,

Was the top speed achieved at redline or at 6400rpm?

not too shabby there.

My car, given enough road to hit the top speed, will top out at around 150 mph give or take. probably around 147.

Gotta love knowing it will do it if given enough time.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

Man! Unless there was somebody in the back seat, you've got a lot of testicular courage to hold and concentrate on a camera doing 140 in the middle of the night!

On another note, I have read many times that speedometers tend to lie or exaggerate at higher speeds. I would say that the best and maybe only way to test true top speed is with a radar gun, preferably not involuntarily! And if you don't have access to a "friendly" radar gun, which most of us don't I assume, I guess you could do it the same way they do it from the air...mark 2 spots on the road, measure the distance, get to top speed, have a friend time how long it take you to get from one to the other and do the math. Just a suggesstion I guess.

I can't wait to top out my car! I've only had it to 115-120ish and it wasn't even breathing hard, so I am curious as to what it's got.

__________________
'86 420SE Euro
904 Midnight Blue, Gray Velour
Dad bought it new, now I own it.

"A Mercedes-Benz is like a fine wine, it only gets better with age."

Hi,

nice picture
But, you should check or change your thermostat, the temperature is a bit low, the needle should be above 80°C.

What tyre size do you drive? IMHO the engine is reving a bit high for 145mph... if bone stock means, you have a 2.87 diff.
And: "economy" shows , that you are off the gas?

This ist my 300TE with the (european) 3,27 diff, front intake scoop cut but still with complete cats at a legal run on the Autobahn last summer:



bis denn,
Christian

1989 300TE

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compare the economy gauge readings from the 2 pictures - in the first picture, it indicates a low engine load (maybe off-throttle after bouncing off the limiter?).

in the second picture (Chris Martens), the engine is at a very high load (which is more reasonable, as the car will be encountering a lot of aero drag).

also compare the times indicated on their clocks - that from Germany indicates that the speed is legal (!)

Great picture of your Mercedes doing what its was built for-speed-they hunker down at speed.

enjoy your drive, timreid

__________________
timreid
1992 400E
euro lights
500E sway bars
210 16in wheels

mbtjc is right, speedos are often very inaccurate especially at high speeds. Best way to tell for sure is with a GPS, as most of us don't have access to radar guns. My diesel topped out at 125mph (according to the GPS) and that's with fat, heavy wheels & tires (225/45/17 on 8.0, compared with 195/65/15 on 6.5 stock). I bet with the skinny tires it would have tagged 130. Borrow a friend's GPS and see how close your speed is at ~100mph, if it's dead on, your top speed photo might be pretty close (say within ~5mph).

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Hey, thanks for the reply. The engine temp on my car always sticks around 80... and here being in Washington is was about 35 degrees Farenheit that night. Also, I only did one quick top end run I didn't hold it very long.

As far as the engine speed, I agree with you there. I always thought my car was revving pretty high when I cruise on the freeway. It tends to be around 3000rpm at 65mph - it makes for GREAT throttle response but it's a little noisy through my gutted precats and I'm not sure if my milage is up to par. I don't know much about the rear ends of these cars.... you say it's probably a 2.87? That seems even a bit tall geared in my book but I guess those tranny's must have some short ratios. What's the norm and the range for the rear ratio on these cars? Oh by the way I have stock sized tires, they're 195/65/15 GoodYear Eagle HP's.

I like your pic, it must be nice having a legal place to do that. you're on euro 3.27 rear? Looks like about 225kph to me which is like what? Just under 140mph?

As for the other questions/comments... The economy meter is down because it had just bounced off the rev limiter as I had mentioned before. I'm not sure if it's a fuel cut or an ignition cut but it was indicating full load until it cut at just about 6500rpms... I think it was a little lower at maybe 6450.

I didn't have anyone else in the car because I don't like risking other people's lives doing something this stupid and illegal but I had a good straightaway and my car was still rock solid at that speed so getting the snapshot with one hand was really no problem.

Thanks for the replies

Oh and as for the accuracy of speedos... I agree there. I don't know how far off these ones are because I don't have a GPS but I have heard all cars are usually a little off and the error increases the faster you go. Then again these were more built for high end speed so maybe they're a bit more accurate Anyways I guess we won't really know unless someone gets a radar gun or a GPS

__________________
-Kevin

A cool 69mph (I had a nice long runway) in my old 1981 240D...

It is 4:05pm on Rt 95 somewhere in South Carolina, so the speed limit was 65.

I think that the 100mph speedo was wishful thinking on Mercedes Benz part. My mom's 300D had about an 85mph speedo and that would have been a better fit in the 240D, which I was able to get to 91mph *once* - Rock solid though, just out of engine.

As "sluggish" as that car was, I miss it. You couldn't kill it.

-Tad

long live the diesels

__________________
-Kevin

Hi K,

I'd like to have a name from you, more than an acronym

Again: under 80°C is too low, change your thermostat. The reading on my temp gauge is "normal", even at low outside temperatures.
I personally wouldn't go for a "quick top end run" without completely warm up the engine and the oil. But: chacun a son goût.

That seems too much to me! You should have 2600rpm at 65mph. Maybe the speedo is reading wrong...

300TE USA-version had the 2.87 diff, Europe had the 3.27 diff. So 2.87 is not really short

The rev limiter cuts the fuel supply, the eha gets -60mA (no pressure difference, no injection) and the fuel pumps are switched off.
No iginition cut off with cat engines

bis denn,
Christian

1989 300TE

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improve your German - please visit my homepage :-)
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Chris,
Once again thanks for the replies. Sorry, I forgot to include my name, I have now fabricated my name into my high tech sig

I talked to a few people about my engine temp and thermostat and they seemed to be about on par with you so I think I will check it out and maybe replace it soon.

You had me going on the whole gearing thing so this afternoon I borrowed my co-workers GPS to see what I could find out. I had my co-pilot run the check and my results were not really catostrophical. From 0-60 the speedo was dead on. At about 65mph on my dash, the GPS was reading just about 66 and at a speedo indicated 80mph the GPS was reading just under 82. In this case I don't think my speedo is really that far off... however the incriments of error will increase the faster I go.

Also, I wanted to confirm my engine speed again. My results were that I was right on 3000rpms when I hit 65mph, at 60 it was about 2800 and at 55 it was 2600. I didn't have my digi camera with me but I did find another picture of a run I did on the way home from Seattle last weekend. This shot was taken at like 3AM on an open freeway... once again I had just let off the gas to take the picture if you're wondering about the economy gauge:


Anyways, I don't know what the hell the guy did to my car before I had bought it from him because I did not buy it new but I am the 2nd owner and I haven't done anything to gearing. I was not used to the cruise rpms when I first got it and I thought there was an overdrive or something that I couldn't find, especially since I didn't know about the 2nd gear start and I only saw it using 3 gears. But then I found the kickdown and figured out the shifter 1st gear drop and I saw it was hitting all 4 gears and I got used to it and now figured it was normal. I have been looking around and I found some sites that sell all the way up to like 4.10 gears for these cars... that would be crazy....

Anyways I'm still curious as to what's going on with my car... I'm just a confused guy right now. Either way I guess I'm happy though... I don't really need gearing that will get me above 145mph and with shorter gears I will get better acceleration out of it.

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-Kevin

when measuring the rpm/mph in an automatic car, be sure that you measure it at a point when the torque converter is locked in at that gear.

in a given gear at a given speed, when the torque converter is not locked, the rpms will be higher than when it is locked.

i don't know the characteristics of a Benz auto transmission (mine is manual), or when the torque converter locks, but I just thought I'd share this ...

Good point. I as well don't know a lot about the characteristics of these autos but I would assume that at the rpms I was running, the converted should have been locked at that point. Maybe we can get some of the pros to step in and give their piece...

__________________
-Kevin