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 01-30-2007, 09:07 AM
BENZ-LGB's Avatar
Strong, silent type
 
Join Date: Apr 2001
Location: Southern California
Posts: 1,663
Question Differential ratios--what does it mean?

OK, what is the importance, or the significance, of different differential ratios?

For instance, in 1991 a W124 300CE had a rear axle ratio of 3.06:1.

The 300TE had a rear axle ratio of 2:87.1.

The 300SL had a rear axle ratio of 3.69.1.

What is the difference in performance? Acceleration? Top speed? Gas economy?

Thanks.

__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!
Reply With Quote
  #2  
Old 01-30-2007, 09:18 AM
Sportlines
 
Join Date: Oct 2004
Location: Johnson City, TN
Posts: 985
Just do a google search using let's say "Automobile Differential"
You will get very complete answers with illustrations.

http://web.mit.edu/2.972/www/reports/differential/differential.html

Steve
Reply With Quote
  #3  
Old 01-30-2007, 11:07 AM
Member
 
Join Date: Jan 2003
Location: Florida
Posts: 1,084
It is pretty simple, the higher the ratio in the rear end, the faster the drive shaft will turn, the faster the engine will turn, the more gas it will burn. The other side of the equation is, you will have more torque at the rear wheels, faster accelleration, lower top speed?,
Reply With Quote
  #4  
Old 01-30-2007, 11:09 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
OF course differential ratios are dependant on engine performance & weight of car....ALSO a big factor is the transmission final ratio as well.

UNTIL 1990 MB only offered a 1/1 final transmission ratio in their auto transmissions. After 1997 all MB auto transmissions are overdrive units.

overdrive units allow for a Numerical righer ratio.
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #5  
Old 01-30-2007, 03:41 PM
Registered User
 
Join Date: Aug 2002
Location: Southeastern PA
Posts: 3,035
BENZ-LGB, with a 3.06 differential the driveshaft turns 3.06 times for each turn of the rear wheels. Higher number differentials produce more torque ... some hot rods had 4.11 differentials ... and lower top end speed. Conversely, lower number differentials produce less torque and higher top end speed.
__________________
Fred Hoelzle
Reply With Quote
  #6  
Old 01-30-2007, 06:59 PM
BENZ-LGB's Avatar
Strong, silent type
 
Join Date: Apr 2001
Location: Southern California
Posts: 1,663
Quote:
Originally Posted by Ferdman View Post
BENZ-LGB, with a 3.06 differential the driveshaft turns 3.06 times for each turn of the rear wheels. Higher number differentials produce more torque ... some hot rods had 4.11 differentials ... and lower top end speed. Conversely, lower number differentials produce less torque and higher top end speed.
Fred:

Thank you for the info. That would explain the higher numbers for the 300CE and the 300SL.

Again, thanks.
__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!
Reply With Quote
  #7  
Old 01-30-2007, 07:27 PM
Registered User
 
Join Date: Aug 2002
Location: La Quinta, CA
Posts: 271
Ferdman said: "some hot rods had 4.11 differentials"
_________________________________________________________________
The real street rods and 1/4 mile drag strip racers ran 4.56 or even 5.11 gears. Not as much top speed....but you sure get to the car's top end quickly. Downside is more engine wear per mile of driving, lower fuel economy (not that racers cared about that) and a noisy interior due to more engine and exhaust noise.

__________________
1986 560 SEL (159K miles)
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 09:40 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, 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