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    • What car holds the record for highest speed on a public road? The 1938 Mercedes-Benz W125 Rekordwagen

      An automotive speed record that still stands from the 1930's? Yep. It belongs to Mercedes-Benz and the W125 Rekordwagen which hit 268.9 miles per hour or 432.7 kilometers per hour over a flying kilometer run.


      To put this in perspective the Bugatti Veyron set a top speed record with a 254.05 mile per hour or 408.84 kilometer per hour run. The SuperSport that followed hit 267.856 mph or 431.072 kph. Yes, bested by a Mercedes from 1938 with a .18 coefficient of drag.

      Here are the specs:


      • Engine: MD 25 DAB/3 60 Degree V12
      • Engine position: Front longitudinal
      • Aspiration: Twin Roots superchargers
      • Valvetrain: DOHC 4 valves per cylinder
      • Displacement: 5,576.75 cc / 340.31 in³ (82.0 x 88.0 mm)
      • Compression: 9.17:1
      • Power: 541 kW (736 PS; 725 hp) @ 5800 rpm
      • Power/displacement 131.97 PS (97.06 kW; 130.16 hp) per litre
      • Power/weight: 621.1 PS (456.8 kW; 612.6 hp) per tonne
      • Transmission: 4-speed manual
      • Engine cooling: Ice supplemented normal coolant as air intakes were kept very small to improve aerodynamic flow over and around the car


      Keep in mind the Veyron Super Sport made its top speed run on a test track and not on a public road. That makes what Mercedes pulled off 79 years ago all that much more impressive.

      Will anyone top this record? Will any government let such a record try take place on a public road? Who knows. What is clear is that the W125 Rekordwagen was way ahead of its time.


      This article was originally published in forum thread: What car holds the record for highest speed on a public road? The 1938 Mercedes-Benz W125 Rekordwagen started by Sticky View original post
      Comments 13 Comments
      1. M-Theory's Avatar
        M-Theory -
        Pretty cool, didn't even know this thing existed. A V12 root s/c motor is interesting, wish we had a sound clip.
      1. Surquhar's Avatar
        Surquhar -
        Wow - that is incredible, especiallly on a public road. That driver had some balls.
      1. DavidV's Avatar
        DavidV -
        Yes, this was Hitler's propaganda engine in full working order.
        Hail to the Autobahn and National Socialism in Germany.
        Please see this in perspective of that time.

        It was an empty autobahn in a time no country had this kind of public road.
        But it was a great performance of the car, and a tribute to Mercedes engineering non the less.
      1. 65AMG's Avatar
        65AMG -
        http://www.traumautoarchiv.de/html/1205.html

        More pictures of the car from Mercedes-Benz Museum Stuttgart
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by M-Theory Click here to enlarge
        Pretty cool, didn't even know this thing existed. A V12 root s/c motor is interesting, wish we had a sound clip.
        Twin roots...
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by DavidV Click here to enlarge
        Yes, this was Hitler's propaganda engine in full working order.
        Hail to the Autobahn and National Socialism in Germany.
        Please see this in perspective of that time.

        It was an empty autobahn in a time no country had this kind of public road.
        But it was a great performance of the car, and a tribute to Mercedes engineering non the less.
        True but it still was a public road and the autobahn still exists. As does the record.
      1. leveraged sellout's Avatar
        leveraged sellout -
        I wish MB would build this engine now, and put it in the 65 cars. Would be better still than the current biturbo V12, I think. Imagine this engine being built with modern materials, construction, materials analysis, computers, etc. Would be absolutely insane. Can you imagine a twin-supercharged, quad-cam 60 degree V12 screamer with all that power and torque? We need this in the world....
      1. 65AMG's Avatar
        65AMG -
        Yes, it is very impressive for the 1930s. But the speed mainly comes from the aerodynamics (and engine-power). I read a long article about this car and they put a lot of effort into the aerodynamics to keep the car on the road. They were in a german aerodynamic centre for aeroplanes to develop because before the final setup there was a nearly an accident at 400 KM/H before this record, as the front of the car nearly lifted up on the road. Drag coef. was even lower than 0.18 in the last setup. The driver said that the car was very stable now and he felt comfortable, in comparison with the old setup.

        Powerwise as you speak of the current V12 from MB, put it in this car, make a software tune to 730 HP and on pump gas it will be as fast as the record car from the 1930s...
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by 65AMG Click here to enlarge
        Yes, it is very impressive for the 1930s. But the speed mainly comes from the aerodynamics (and engine-power). I read a long article about this car and they put a lot of effort into the aerodynamics to keep the car on the road.
        They did it all without computers... that is even more impressive.
      1. 65AMG's Avatar
        65AMG -
        https://m.youtube.com/watch?v=i5Ac5YVHsbk

        Here is a video of the car in action. I think this is a little before the record run, because of the different front of the car. For the record run they drove without engine radiators to have better drag coeff.
      1. Sticky's Avatar
        Sticky -
        Embedded:

      1. 65AMG's Avatar
        65AMG -
        In 1939 they had another car ready named T-80, which should achieve 600 KM/H 373 MPH but then world war 2 broke out and the project was cancelled. Unbelievable for this time...
      1. 65AMG's Avatar
        65AMG -