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 ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-07-2002, 02:48 PM
Registered User
 
Join Date: Jul 2002
Posts: 50
Unhappy Poor Gas Mileage on '93 400E

I have a '93 400E with about 60k mi. on the clock. It seems to run very well and is smooth and powerfull but I only am getting about 9 mpg in the city. I do tend to push the pedal to the floor quite often and I expect that my mileage definately should suffer but I'm consistantly getting the 9 mpg even when I try to take it easy for a tank. I've replaced the spark plugs and removed and cleaned the distributors and rotors when I first bought the car. That had a noticable effect on the power but didn't affect the mileage. I'm thinking of replacing the dist and rotors now.

Can anyone suggest what the problem could be?

Are there any other owners of 400E's who drive them aggressively in the city who are getting higher mpgs?

Thanks for any help.

Jerry
Reply With Quote
  #2  
Old 12-07-2002, 04:19 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
A bad O2 sensor would cause your mileage to tank like that.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #3  
Old 12-07-2002, 05:28 PM
Registered User
 
Join Date: Jun 2001
Location: Omaha, NE
Posts: 962
Not sure what the problem is but you should certainly get a log better mileage. I have never gotten below 19 or 20 mpg in town. I don't floor it after every stop light but I'm not gentle on the accelerator either.

Have you pulled the codes?
__________________
Steve
'93 400E
Reply With Quote
  #4  
Old 12-07-2002, 07:36 PM
Registered User
 
Join Date: Oct 2001
Location: Canada
Posts: 298
I drive my 400E pretty aggressively, I often shift the transmission by myself and heat 80kmph in first gear.

We use winter gas in Canada, my gas mileage is now 12.5L/100km (18.8 mpg) for combined highway/city stop and go traffic. If I take it for a long highway ride, and keep the speed at 120-140 kmph, I normally get below 10L/100km (23.5 mpg). It does better than this in summer.

9 mpg is definitely unacceptable unless you drive on a race track and keep your engine rpm above 4000 all the time. Like other has suggested, O2 Sensor should be checked, I would guess somebody can see black smoke from your tail pipe with that gas mileage.
__________________
99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.
Reply With Quote
  #5  
Old 12-10-2002, 01:19 AM
Registered User
 
Join Date: Jul 2002
Posts: 50
I have not checked the codes yet. I will have to research how to do this so I can avoid the dealer. I do remember seeing some slight black smoke on the accelerator ramp and night. Will the codes tell me if the O2 sensor is bad?

Jerry
Reply With Quote
  #6  
Old 12-10-2002, 01:47 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
Yes.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #7  
Old 12-10-2002, 05:35 PM
G-Benz's Avatar
Razorback Soccer Dad
 
Join Date: Apr 2001
Location: Dallas/Fort-Worth
Posts: 5,711
I know dirty fuel injectors can severely affect mpgs.

They may need cleaning, but MB says DO NOT use injector cleaners of any kind!
__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car
Reply With Quote
  #8  
Old 12-10-2002, 07:01 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
The only thing that can catastrophically cause your gas mileage to drop from about 20 mpg to about 8 mpg is your O2 sensor.

This is the characteristic symptom of a bad O2 sensor.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #9  
Old 12-14-2002, 06:29 PM
Registered User
 
Join Date: Jul 2002
Posts: 50
Just got back from my mechanic who hooked up his computer to my car. There were no fault codes and he assures me that everything was running within specs. I watched the O2 sensor millivolts vary from about 80mv to 800mv. He said that was normal and that meant it was doing its job.

His explaination for my 9mpg was that I may have had the A/C on or that I was just driving it hard. The truth is that I do like to speed away from a standstill and I do accelerate quite often. I guess I'll have to take it easy for a while and see how that affects the mileage. I'm a little dissappointed since I was expecting to get at least 16 mpg with my driving style in city driving.

Anyway, thanks to all for the help.

Jerry
Reply With Quote
  #10  
Old 12-14-2002, 10:32 PM
Registered User
 
Join Date: Jan 2001
Location: Hurley, N.Y.
Posts: 11
I don't know if it aplies to your vehicle but I have a '91 300E that black smoke would come out of the exhaust when accelerating hard and was getting really poor mpg. Fuel distributor was bad replaced it and now the car runs great.
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 09:32 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page