I am thinking that a new timing chain might be good JuJu for my car. I am pretty sure nothing has been done to in 202K.

Since the arv and EGR has been neutralized I bet the mileage might be better with taller gearing.

Edit : My mileage has always been 15-20% better than EPA.

__________________
85 Merc 300D - Unwinding 31 years of wear
86 VW TD
Mahindra Diesel
Iseki Diesel

In 2007 I didn't own a diesel.

One would need to have knowledge of "cold 75" test procedure that is utilized for these tests to fully understand why a diesel powered sedan with 125hp would be rated so poorly.

The explanation is as follows:

To keep the vehicle on the test curve requires a considerable amount of boost and operation of the engine at above 2800 rpm on nearly every accel. There is no possibility of driving it for any sort of economy. As you know, the more boost you use with the diesel, the more miserable your fuel economy.

My original statement regarding fuel economy for this vehicle is valid only if you choose to drive it conservatively and not attempt to keep up with the gassers. I have proven my statements on two different vehicles of this type and can assure you that they do not get a combined fuel economy of 20 overall unless the vehicle is not properly sorted or you drive it like an idiot.

There is no other possibility.

The required "dose of reality" needs to be provided to others. Getting fuel economy in the range of 22 mpg for an SD is ridiculous.

I agree that the EPA ratings are dismal. In evaluating any given car, I always look at MPG plus particulate emission. Black clouds indicate waste and inefficiency.

But getting back to EPA ratings- these are at least an accepted scientifically backed rating (whether you believe in the particular science behind it or not), whereas a Brian Carlton rating is not.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.

Thank you all for the help!

Actually, I had an emissions test the other day and was five percent opacity. You can get a quick root beer cloud but then goes to a quick haze if one REALLY buries the pedal.

If my fuel was free, I still care about the consumption because of the environment. The more efficient the less pollution.

Brian, remember the SD has less drag than a D and bet the TD is even more plus weighs more.

I am not a moron, as more accidents happen because of lack of speed. In the desert the speed limit is 75M.P.H. and most folks go at least 80 to 90M.P.H.. At 75M.P.H. the R.P.M. is 2.500. At that I got 25 to 26M.P.G..

I have plenty of acceleration after about 2.000R.P.M.. I find no need except in VERY rare occasions for the kick-down. Guess I am lucky!

What! I thought you said you never got over 25? I have gotten between 25 and 26M.P.G.. This last tank with mostly city driving and stop and go traffic. Filled up with 8.5 gallons traveling 232 miles, so I got 27M.P.G.! Seems odd that removing the A.L.D.A. increase efficiency, but does coast better.

Good point! The E.P.A. tests all vehicles the same and gives a reference point. If the given auto is worse then really need to take a look at why. Also, good point about the particulate and considering I don't put out much at all, should be alright for now.

__________________
Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.

"...but I did last summer."

Clause listed above^

I don't usually track MPG but on occasion, I do. Since you mentioned it, I have filled my car to the brim and I will be seeing how many miles I get until I am critically low on fuel. I will then fill it to the brim again, subtract factory spec tank volume from what I refilled with and divide that by miles traveled. I am not currently running WMO, so these results are on straight D2. I may add some DK for IP lube purposes.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

As for environmental concerns about running WMO: Either I can run it as fuel or ships/ocean liners can run it as fuel. I choose it to be me. I'm not on the environmental band wagon but if I can stretch a tank of fuel, I will try any reasonable measure to do that.

Like I said, my car is probably not perfect when it comes to timing, so I do not expect maximum efficiency. Next valve adjustment, I will look at my timing chain stretch and see where to go from there. I believe compression is good since I have low blow by and the car starts quickly. I still need to do a definitive test.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

I can only offer the data that I have. It is as "scientific" as my test conditions allow.

The SD gets a documented 29 mpg over 16 tanks over the course of four months. The odometer is accurate to .1%.

You can use it as you wish. If you want to believe the EPA ratings, you must discard my data and all the data of others who get in the range of 27 mpg with this vehicle (including Dr. Bert).

This would assist in confirming whether your range estimate is realistic or not. However, more than one tank is typically necessary for accuracy due to the error associated with the filling procedure.

Yes, the SD has an advantage over the W123. Makes it very difficult to obtain 30 mpg with it.

I run the SD at 62 mph and have yet to have an accident due to the "lack of speed". That's a new argument that I haven't had the pleasure of hearing before.

At 75 mph, the engine speed will be 3200 rpm with a 2.88 axle. Unless you have installed 2.20 axle (not possible on a W123) your engine speed is not 2500 rpm. So, I conclude that your data is inaccurate.

62MPH may be OK in NY. Heck in NYC, I am lucky to average 15 MPH! None the less, speed limits up in the north country are lower than in the south. Here in TX, we see traffic flowing at a minimum of 75 MPH. New routes are now rated at 75 MPH, which seems to dictate people drive at 85-90MPH. If you are rolling at 62 MPH, you are quickly passed. You will spend your day in the right lane tourtiosing along. I usually cruise at 65 MPH and I am always being passed. It's not a problem of cruising at a lower speed rather than being in a situation where the speed determines the outcome. You don't have to be the cause of a crash to be a part of one.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Right... Merging onto a busy interstate at rush hour is one situation that comes to mind.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.

I think Brian's idea of "proper driving" is about 180 degrees out from mine. An example of my idea of proper driving:

Fastest motorcycle lap of the Nürburgring. 7m10s BTG Yamaha YZF R1. - YouTube

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

If you wish to drive in such a fashion, why own a slow diesel? Get a 250hp gasser and have at it. The fuel economy is about the same and RUG is a hell of a lot less costly.

The benefit of the diesel is that you can obtain the fuel economy benefits. The gasser, unfortunately, due to throttling, is limited on the fuel economy benefits obtained by conservative driving habits.

If the SD got 22 mpg on diesel, I'd be an absolute moron for keeping it. The BMW 740iL gets identically the same mileage with a 280hp V8, independent of driving habits (and it weighs 800 lb. more than the SD).

The discussion of speed is relevant to fuel economy in a significant way. The SD can obtain 29 mpg largely as a result of driving it at 62 mph. The loss of time relative to those driving 67 mph in a one hour trip is insignificant. In fact, rarely can those who drive faster sustain an overall average speed. One additional traffic light at the beginning or the end of the trip and the entire benefit of the additional speed is cancelled out.

I believe your intent is that "acceleration" determines the outcome. There are certainly conditions where the maximum available horsepower of the SD is necessary and I have no problem in using it.

I have the slow diesel for several reasons:

1. I can flog the wee out of it and still get 25 mpg.
2. It's more fun to drive a slow car fast than a fast car slow.
3. Having a slow car seems to help cut down on the speeding tickets somewhat.
4. I like diesels.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.