Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: KenO on September 30, 2013, 01:53:49

Title: ??Normal RMP at 65mph ??
Post by: KenO on September 30, 2013, 01:53:49

I am new to this group and have just purchased my umptheenth MBZ but finally have my dream car - a 1971 280SL    Question, What is a normal RPM for a '71 280SL with the 4 speed Automatic transmission at freeway speeds.  I am running about 3500RPM to get 65mph.  With 4th gear selected I understand I should only expect to feel 3 gear shifts, and that is what I am getting, but this seems like an unusually high RMP.   Thanks, Ken

Title: Re: ??Normal RMP at 65mph ??
Post by: Garry on September 30, 2013, 02:47:16

Hi Ken,

Welcome to the Group.  The RPM that you are getting is correct, they were always a fairly high revving engine and whilst some have fitted various different 5 speeds that will take off a few hundred revs, some here think that the engine should be driven how it was designed to work, i.e. higher revs.  Also as an Auto, the vehicle will always start in second with the stick in forth. If the gear lever is pushed forward to 2 then it will start in first.

Have a good read through the Tech Manual and also try out the search engine on RPM or similar and you will see lots of posts on the subject.

Add some photos in the Photo section of the Forum for all to see, everyone loves a photo and ask questions as needed, there is a wealth of experience here on these cars. 

If you feel that you are getting value from being here then feel free and I encourage you to join as a full member  for a small annual subscription that contributes to the running internet hosting costs of the Group given that all positions are voluntary. (I had to get that plug in as the Membership Officer for other than the Americas)

Garry

Title: Re: ??Normal RMP at 65mph ??
Post by: iftykhan on September 30, 2013, 07:55:50

Hi Ken,

I have only owned my 1969 280 auto a few months, and like you, thought the engine felt 'revvy' and the gearbox noisy but my mind was put at ease by several passionate and knowlegdable members.

I completely concur with Gerry re becoming a member-I have learnt so much about our wonderful cars through the forum and tech manual.

Regards
Ifty

Title: Re: ??Normal RMP at 65mph ??
Post by: kampala on September 30, 2013, 20:06:26

KenO,

Welcome to the group.  To help you get started with the search ... here's one link with a RPM / Speed chart from a very well respected member ...

http://www.sl113.org/forums/index.php?topic=18239.msg127406#msg127406

Title: Re: ??Normal RMP at 65mph ??
Post by: KenO on October 02, 2013, 01:51:03

Thanks for the answers!!
 
I am feeling much better about how she is running.  This poor car had been sitting for about 15 years and I was quite concerned.  I flushed out the fuel system, oil and transmission fluid and have run her now for about 200 miles and 3 fluid changes, she is sounding better every minute!

Ken