Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-01-2017, 01:26 AM
Registered User
 
Join Date: Feb 2017
Location: Southeast Texas
Posts: 18
How fast should I drive my 240D?

Hello all,

I apologize if I'm not in the correct thread location.

I have recently bought my first 240D. It's also my first diesel car. And my first Mercedes... So basically, I'm a complete noob on this topic.

My question is, is ok to drive 60-65 on the highway? I just feeling like I'm revving the engine to the moon at such speeds. The car is an 83' with the 4spd manual. I'm assuming it has the higher ratio rear end, and that at 60 mph the engines turning at about 3000 rip 'ems. Could I swap the differential for say the 2.88 from another car? Would that even be beneficial? Where would I get said diff? I live in a flat area so hills aren't a concern. And hey, I bought a car with 64 horsepower, I'm not a speed demon either.

Thanks for the help.

Reply With Quote
  #2  
Old 02-01-2017, 09:09 AM
Registered User
 
Join Date: Feb 2016
Location: Winston Salem, NC
Posts: 9
First, congratulations on your 240D! No problem with high rpm. My '88 300SEL also runs at the same high rpm. Most 4 cylinder diesel pickups in the rest of the world also runs the higher rpm without problems.

As far as swapping the differential, I will leave that to the experts!
__________________
2012 Mercedes E350
1988 Mercedes 300SEL
1996 Nissan Pickup
2003 BMW K1200GT
Reply With Quote
  #3  
Old 02-01-2017, 11:18 AM
Registered User
 
Join Date: Jan 2006
Location: Tucson, AZ
Posts: 4,632
Assumptions are dangerous. Inspect the differential to verify which one you have.
__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now
Reply With Quote
  #4  
Old 02-01-2017, 11:49 AM
Registered User
 
Join Date: Oct 2007
Location: Greater Metropolitan Beaverdam VA
Posts: 2,578
I would not change the diff

I think you would be sorry you did. Flat terrain or not the car would not be able to accelerate acceptably or possibly even safely. Benzo engineers know their stuff and selected the ratios for the best performance - economy tradeoff.
Reply With Quote
  #5  
Old 02-01-2017, 01:50 PM
Fold on dotted line
 
Join Date: Aug 2007
Location: SE Mich
Posts: 3,115
Quote:
Originally Posted by knightwrider View Post
Hello all,

I apologize if I'm not in the correct thread location.

I have recently bought my first 240D. It's also my first diesel car. And my first Mercedes... So basically, I'm a complete noob on this topic.

My question is, is ok to drive 60-65 on the highway? I just feeling like I'm revving the engine to the moon at such speeds. The car is an 83' with the 4spd manual. I'm assuming it has the higher ratio rear end, and that at 60 mph the engines turning at about 3000 rip 'ems. Could I swap the differential for say the 2.88 from another car? Would that even be beneficial? Where would I get said diff? I live in a flat area so hills aren't a concern. And hey, I bought a car with 64 horsepower, I'm not a speed demon either.

Thanks for the help.

I have been advised by MB that the 616.912 engine + MT should not be driven for sustained periods over 4500 rpm.


I have driven at 3500-4000 at 70-72 mph for extended periods with no ill effects.


This car has 132,000 miles and is kept in top shape valve- and injector-wise.

What it all really depends on is the cruising rpm for the vehicle engine. That's the one for which high-speed cruising (Autobahn) is designed.

FWIW
__________________
Strelnik
Invest in America: Buy a Congressman!

1950 170SD
1951 Citroen 11BN
1953 Citroen 11BNF limo
1953 220a project
1959 180D
1960 190D
1960 Borgward Isabella TS 2dr
1983 240D daily driver
1983 380SL
1990 350SDL daily driver alt
3 x Citroen DS21M, down from 5
3 x Citroen 2CV, down from 6
Reply With Quote
  #6  
Old 02-01-2017, 09:32 PM
Registered User
 
Join Date: Feb 2017
Location: Southeast Texas
Posts: 18
Thanks guys for all the inputs. It makes me feel a lot better knowing that I'm not ruining my brand new (to me) Mercedes by driving her at 60-65. By the way, it has 266,000 miles. The engine is in fantastic shape and was well taken care of. I suppose I'll stick to regular maintenance and see how far she goes. Thanks again for the help
Reply With Quote
  #7  
Old 02-02-2017, 10:36 AM
gatorblue92's Avatar
Save the manuals!
 
Join Date: Jan 2006
Location: Delaware
Posts: 3,362
I have driven mine at 70 for years with no ill effects.
__________________
1977 MB 240D 4 speed 145K - Nearly Perfect
1993 MB 400E 218K - Weekend Toy
2018 Ford F150 5.slow 23K - My DD
2020 Subaru Ascent 5k - Wife's DD

1979 MB 280E 90K - Sold
1983 MB 240D 238K - Scrapped
1984 MB 300D 347K? - Sold
1984 MB 300TD Wagon - 188k - Sold
1987 MB 300E 5 speed 258K - Scrapped
1991 MB 300TE 5 speed 276K - Sold
1993 MB 400E 130K - Sold
1995 MB E320 Wagon 190k - Sold
Reply With Quote
  #8  
Old 02-02-2017, 11:02 AM
tyl604's Avatar
Registered User
 
Join Date: Feb 2008
Location: Atlanta, GA
Posts: 3,235
Most likely the car will outlast you. I am still racing my 1981 300SD to see who gets to the end of the trail first. So far it is doing better than I am. Good luck. They do not make them like this any more.

Last edited by tyl604; 02-02-2017 at 11:46 AM.
Reply With Quote
  #9  
Old 02-02-2017, 02:48 PM
Registered User
 
Join Date: Dec 2002
Location: New Castle County, DE
Posts: 1,032
IIRC older (late fifties/early sixties) Mercedes owner's manuals would state a cruising speed and a top speed. Often they were the same.
__________________
Hanno
'79 6.9 Sold (after 27 years of ownership)
'83 280SL, 5 spd.
'94 E320 Sdn. 5 spd conversion
'95 E320 sedan
'02 E320 Sdn.(on loan to mom!)
'87 300E (5 spd. conversion) Sold
'05 E500 Wagon
Reply With Quote
  #10  
Old 02-02-2017, 03:16 PM
Registered User
 
Join Date: Aug 2002
Location: Southeastern PA
Posts: 3,014
knightwrider, it strikes me that any engine speed below the Red Line on the tachometer should be OK indefinitely. As mentioned, MB diesel engines last for hundreds of thousands of miles if maintained properly. It's likely the body will suffer from major rust issues before the engine dies.
__________________
Fred Hoelzle
Reply With Quote
  #11  
Old 02-02-2017, 05:16 PM
Administrator
 
Join Date: Mar 2016
Location: Los Angeles, CA
Posts: 1,730
As mentioned by other members, older diesel engines tend to run on high RPMs with zero issues - maintenance is key. Enjoy the new ride.


-Dmitry
Reply With Quote
  #12  
Old 02-02-2017, 06:20 PM
Registered User
 
Join Date: Oct 2004
Location: seattle
Posts: 38
I ran my OM615 manual up to its top speed of 84.3 mph. Not for overly long periods, but she was able to get there and stay there for at least a few miles at a time. I found that she was most happy cruising at 70mph on trips to Portland (350 round trip). Mountain passes seemed to top out at 60mph on steep slopes. Speed drop from 70 to 60 over a five or six mile climb
__________________
clay

2002 s430 - Victor, a Stately & well tailored chap
1974 450sl - Frosch - Two tone green
1986 SDL - Polei

retired models-
1976 300D - Blei Vanst - it looks silvery
1972 220D - Gump - She was green, simple and ran
1995 E300D - Gave her life to save me against a Dame in a SUV
POS 1987 SDL - Beware Nigerian Scammers
Reply With Quote
  #13  
Old 02-02-2017, 07:42 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,538
You can do as fast as the car will allow, but I wouldn't do that for long or often. I was able to get my 77 240D auto up to 95mph but usually it did fine going about 75mph, anything above that and the temp would start to creep up, not sure if the cooling system was in top shape though.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #14  
Old 02-02-2017, 08:27 PM
Registered User
 
Join Date: Jan 2012
Posts: 7,488
With a diesel, the governor in the injection pump will limit RPM by pulling back the fuel. Have a look at the numbers on the pump / governor. Many times the RPM is listed in the number but remember, this is pump speed so double the value.
Reply With Quote
  #15  
Old 02-03-2017, 03:43 AM
Registered User
 
Join Date: May 2009
Posts: 274
I though that, with all Mercedes, you drive them as fast as they will go. I used to do that and the others on the Autobahn seemed to be doing likewise. 80 million Germans can't all be wrong!!!

RayH

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 12:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page