WordSmith

I own a 2005 SL500, with no performance modifications of any kind. I was alway under the impression that the top speed of the car was electronically limited at around 150 mph. I recently was able to open the SL up and pinned the speedometer at 160 mph, as shown in the attached photo. Additionally, even though the speedo had reached its limit, you could feel that the SL was still accelerating. Does anyone know the top speed (physical or electronic limit) of a 2005 SL500?

CLK Masters

strange, it should top out at like 130 ish, if you got the sports PKG, maybe 155 MPH. Are you the original owner of the car?

m4xm1l10n

155 MPH , I do it all the time it will show 160 but if you set the digital speed on the dash you will see the 155 MPH mark . All SL are limited at 155 MPH regardless if it has sport package or not . On the other hand my S500 Cuts out at 130MPH !!! sucks

m4xm1l10n

155MPH and only about 4000-4500 RPM , Get an ECU tune and you can get up to 186MPH

WordSmith

I bought the car from a dealer when it was one year old. It had been turned in after a one year lease. I have the original window sticker and it did not come equipped with the sport/performance package.

rcoppens

Please dont take this the wrong way, but don't make estimates if you have no idea whatsoever as to what you are speaking about......the SPORT vs NON is purely cosmetic only. Comments like this mislead folks and are purely speculative at best............

m4xm1l10n

THANK YOU

QuadBenz

WordSmith, next time you're able to open her up again, try switching the menu in the instrument cluster to the electronic read out so you can see if it's still accelerating past 160.

WordSmith

I'll do that. I knew that option was there and have used it before, but didn't think of it at the time.

mikeinsf

Since the sports package does nothing to modify transmission or engine, I wonder if you have any idea what you're talking about.

Artyi

I tried mine once, so I got 259km/h speed. I guess t could go faster, but there were road works..

CLK Masters

This was my point of saying anything about the sports package. On my car the CLK, from my experience, there are a couple of different governers for speed, and these from what i can tell are based on the stock tires your car is equiped with (speed rating)

For instance on some but not all CLK 320's have H rated tires for the Non-Sport model, and are limited at 130 Mph, same as the tire is rated for. However i've been in a clk320 with the sports pkg, with pilot sports on it and that car did 140+, took forever to get there but it DID break the 130MPH barrier.

Now to my car. i have the CLK500, with the "spts Pkg" from the factory with ZY rated tires, my car is governed at 156MPH "tested". as is my cousins CLK500, his will also do 156.

Here's the kicker, before my mother purchased her S550, she had a 2005 S600 with the sports package and it did 155 MPH. My uncle had a 2004 S600 WITHOUT the sports pkg and it did 130MPH.

GO FIGURE.

Hence me asking if he had the sports package.

I KNOW THERE IS NO HORSEPOWER / TORQUE GAIN on the sports package!

Now, since you guys did not know this tidbit of info, it makes me wonder if you guys know what your talking about. Maybe, just maybe you guys shouldn't be so eager to jump the gun on something when you don't have all the info.

CLK Masters

100 bucks says a SL500 WITH a ECU tune, CANNOT do 186 MPH. unless it's free-falling.

My car can't do it, and it's lighter. with the same engine, and i have more than a "tune" done to it.

mikeinsf

The standard tire on my standard 2005 SL500 is the z-rated Michelin PS2. I know nothing of your uncle's S600, but every spec list of an SL500 that I've ever seen has it at 155 limited. I personally don't want to give it test because I just don't want to get busted at that speed. I'm trying to get my good driver discount back, and that wouldn't help.

Rook3300

Boy, we knows you is just frontin' for the popo 'till you get out to da backwoods o' Nevada in the summer. 155mph+ baby! You know you can't resist. LOL

Rook

// wonders how the good driver discount was lost to begin with...

Rook3300

Yep, it all has to do with the tires that are fitted. I know that on older models, not all variations had the 155mph+ tires fitted, so they were limited relatively low. Anything after about 2003-2004 with the 5.0L V8 or more should be about to make it up to 155mph with no problems as the standard tire choice was for the Z-rated tire. This is the limit unless the ECU is reprogrammed to eliminate it.

Rook

Additional: All MB sport cars are fitted standard with Z-rated tires, like SLs and the newer SLK. With other makes/older models, you had to buy the sport package to get the faster rated rubber.

mikeinsf

Hehe... well I've said b4 that I think others are foolish to post their exploits in full detail in any public forum. That said, I really don't relish the idea of getting caught at arrestable speeds.

I lost my good driver discount for a regular old accident that occurred at an intersection here in SF back in August. Actually it was a fairly dramatic accident, though no one was injured. The cop ruled it my fault. I don't agree, but the person on the short end of the stick rarely does. So there went my good driver discount, along with my low rates. Two and a half more years to go.

Are there speed-limit-free stretches of road in NV?

Rook3300

Bah, I was thinking of the salt flats of Utah when I typed Nevada. Perfectly acceptable to hit 155+mph out there. And I think there's a weekend of speed coming up in August (http://www.scta-bni.org/SCTA-NewWeb/Bonneville/2009_Info.html)

I hear ya on the accident. Mine was over 3.7 years ago thank god, though I have to wait for a couple of tickets to come off here in the next year or so. The accident was a double-fault, though I think I was the only one who got a ticket since the other guy was driving a semi and had no damage at all. I was merging onto a highway and the semi in the left lane decided it was a good time to change lanes from the left lane into the right lane. Clipped the driver's front quarter of my car and I wrecked into the side of the truck. The car was totaled but I walked away just fine. Strangely enough, it also helped me to get my finances straightened out since I no longer had the big car payment to make. Weird.

I know there were some in Colorado in the 90's, though I think they are now limited to 80mph in the daytime. Although CO is so desolate, you won't encounter anyone else for dozens and dozens of miles anyway. I think I've heard that state troopers pull people over just to have someone to talk to for a minute.

Rook

CLK Masters

Thank you. +1

m4xm1l10n

Thanks!!!! you said it yourself LIGHTER The SL is slightly heavier so that helps the top speed . With enough road off course . Hey let me get that 100 bucks for gas lol

mlandis

OK, have I said recently how much I love this forum? I think I've learned more esoterica about high-speed driving and my car in this single thread than I would've learned in ages!

IngenereAMG

The roads in NV all have limits, but most are so straight and completely empty that it would be possible to take derestricted SL55 over 200 mph.... but I wouldn't know anything about that!

CLK Masters

WOW, so ur saying a Semi-Truck that weighs 60 tons, is gonna be faster top end than my car, cause it weighs more?

Weight is the ENEMY OF ALL PERMORMANCE!!!!!!! why do you think the 1001 HP Buggati isn't the fastest around the topgear track? CAUSE IT WEIGHS LIKE 4400 LBS.

If your refering to Downforce, YOUR STILL WRONG. Cause a F1 car does like 210 with 4000+lbs of downforce, if you were to adjust the aero work to reduce that, they could close to 300 MPH. although they couldn't corner at like 4G.

but then again. you're probally refering to my statement of the car being in free-fall. say yea MAYBE, if we got 2 planes and push your car and my car out at the same time from the same altitude, yes your's would probally hit the ground first.

CLK Masters

I was reffering to a SL500, with 302 HP.

I know for a fact the SL55 with tune and VMAX removed will do like 204+MPH.

Rook3300

Yep, CLK Masters is right. Weight has little to do with top speed unless the vehicle is really heavy. Top speed is affected by a number of things, like: horsepower, transmission gearing, and Cd (coefficient of drag). Weight is a smaller factor in that unless you have stupid amounts of horsepower, you can't get a heavier car to go faster than a lighter one.

They say that the Veyron only needs about 300 horsepower to make it up to about 180-190mph. It takes the OTHER 700 HORSEPOWER to get to 254mph! This should give you a good example of what drag does to a vehicle. Beyond a certain speed, each additional 5mph of speed requires almost double or triple the horsepower of what the last 5mph required.

Part of the problem with the SL's top speed is that the gearbox isn't set up to do high speed runs. The top gear hits 4500+rpm at 155mph. Get much faster than that and you'll be hitting the redline quickly. And although the car itself is rather sleek, the Cd isn't the greatest so drag is definitely an issue at 150+mph.

By the by, F1 cars are geared so that their top speed is about 190-195 or so. This past F1 season in Singapore (the famous night race), they had a nice long straight in front of the stands (and between turns 5 and 7) where they topped out at about 191mph in 7th gear. F1 tends to lower their top speed so that they get better ratios for the low speed corners. I think they are limited by drag and gearbox to about 220mph (maybe 230mph) or so.

Rook