typical rpm range

[n/a]

In what range should the rpm's be in my '71 280SL when cruising at 50 mph?  Thanks for the info.

[jeffc280sl]

Maybe 2600 rpms

This should help


http://wahiduddin.net/calc/calc_speed_rpm.htm
or
http://www.4crawler.com/4x4/4LoCalc.shtml#SpeedoConverter

Jeff C.
1970 280SL 4-speed

[n/a]

Thanks Jeff

[ted280sl]

I believe there are some variables to consider in answering this question. Automatic or standard. If standard, 4 speed or the rare 5 speed. Which rear end is installed. The Euro models had a smaller rear end and therefore lower RPM's at highway speeds.
  I hate to confuse the issue but, I thought this information would help.
Regards,
Ted 280SL w/ 4 speed and Euro rear end

[Abbas]

Ted,
  I wonder why the Euro models had a smaller ratio and lower RPM than US version. Does this have to do with regulation or .... it is quite interesting to know. Actually, the high RPM is quite anoying some times - you feel that the car is making a huge effort and quite noisy/furious   .

Abbas

280SL W113 1969 Ivory
E280 W124 1995 Silver

[n/a]

U.S. model, 4 speed automatic - Jeff's number of app. 2600 rpm is right about what I am seeing

[Klaus]

Abbas,
regulations are involved inasmuch as the US always had lower speed limits. Therefore, engineering and marketing concurred that European models had to have a high top speed (200 kmh was the design target), while US models had to have better acceleration.

Klaus
1969 280 SL

[Abbas]

Abbas,
regulations are involved inasmuch as the US always had lower speed limits. Therefore, engineering and marketing concurred that European models had to have a high top speed (200 kmh was the design target), while US models had to have better acceleration.

Klaus


Klaus, from this I would understand that MB on purpose made the US version cars with higher ratio so that people cannot drive them at higher speed. Can this be changed by tuning the car or we have to change the whole differential.

Abbas

280SL W113 1969 Ivory
E280 W124 1995 Silver

[jeffc280sl]

Abbas,

I've recently changed out my rear axle in favor of an axle from a 1972 280SE 4.5.  The V8 Mercedes had a 3.27 ratio rear axle.  Do a search on this subject and you will find a lot of information.

Jeff C.
1970 280SL 4-speed

[George Davis]

I think the gearing in the US was market-driven.  US drivers were used to big, torquey V-8 motors that accelerate quickly.  The lower gearing gives the car somewhat better acceleration.

George Davis
'69 280 SL Euro manual

[Cees Klumper]

I changed my differential over from 4.08 to 3.69. There is obviously a difference, however it is not that significant. On the highway, the car still revs much higher than one would expect a six-cylinder to do. Converting all the way to a 3.27 would help somewhat more, however as noted the acceleration would suffer appreciably. I have just gotten used to the fact that this engine actually likes to rev high.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic