Minimum fuel consumption for the 617 turbo is 220 g/kWhr at full load. Unfortunately the reference I found did not specify what rpm this is, but I would assume it is at the torque peak which is 2500 rpm.

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For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

You know, this is a very good point. If you want better economy, a 190 is a lot lighter and That is a huge telling point!

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Thanx,
Alberta Luthier
1983 300CD ('Stinky')155k miles, 2.47 diff, EGR removed, AAZ injectors with 265 nozzles from Sean,and vogtland lowering springs.
1984 300SD ('Old Blue')150k Klicks from Japan originally, came with rear head rests, no sunroof and never had an EGR

Sorry to say I haven't had a chance to very carefully check the MPG, but I have an intuition that it is much better. I thought I would be out this weekend with it on the highway and get some solid numbers, but had a weeping oil cooler line that was getting worse each time I drove it so I parked till the parts arrived this morning. I fully intend to report back with MPG numbers but since I haven't tracked down the right speedometer(from an 83-84 380SE) I will have to do the math carefully, worse I buy fuel in liters = more math.
This is a 'peppy' 300CD and it still pulls well on the highway. Even in the mountains and I seldom have to gear down. It pulls better at 80 MPH than at 65. I have to get the cruise working again because it is very easy to find myself traveling much over the speed limit. At 65 -75 you can hardly hear the motor, of course that is party because being a coupe the windows don't seal that well and there is more air noise than most sedans
I am quite looking forward to seeing what the top speed is going to be, but all has to be just right before I will open her up.

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Thanx,
Alberta Luthier
1983 300CD ('Stinky')155k miles, 2.47 diff, EGR removed, AAZ injectors with 265 nozzles from Sean,and vogtland lowering springs.
1984 300SD ('Old Blue')150k Klicks from Japan originally, came with rear head rests, no sunroof and never had an EGR

what is your RPM ar 65, best you can tell?

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

extreme lightening of the car will net you better fuel econ.. this is what im planning to do with my mercedes.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

I'm going to do some aero mods( nothing too extreme). Today I started doing like pulse and glide, shutting off at long lights, shifting to N at lights, coasting around long corners. driving like grandma, and turned the alda in a little.

Probly not because you'll be lugging the snot outa the engine. Heck my 240D is happiest at 70+ mph and thats in 4th gear without overdrive. MB diesels operate at maximum efficiency at/above 3,000 RPM minimum.

Dunno why everybody thinks that lugging diesel engines far below their power band delivers better fuel efficiency. Most likely the opposite is true as combustion chambers foul at bottom end rpm's where the engine actually works harder to maintain vehicle speed. Nevermind incomplete fuel combustion bein a factor.

And do you by any chance have 240D donor engine ready to install? Better start looking now because low mileage examples are gettin scarce. Probly 1/4 the number of 617's imported to USA equals the number of 616's.

80's VW Rabbit
40+ mpg

Oh, did you want something that's actually COMFORTABLE?

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'79 300SD
'82 Chevy Chevette diesel

The specific fuel consumption at lower rpm's might be a tad higher, however, the fuel savings in significantly reduced engine friction due to the lower rpm's yields better fuel economy.

It's always better to run the engine at lower rpm's and use all available horsepower at that rpm versus using 1/2 or 1/3 the available HP at higher rpm's.

With a 240, however, the point is a bit moot. If you attempted to run the engine at 2500 rpm on the highway, the available horsepower would only allow the vehicle to achieve 60 mph or so.............and that would take nearly forever.

BTW, it's nearly impossible to "lug" a M/B diesel...........they can run at 2000 rpm all day long without any issues. Only if you attempt to run one at 1000 rpm could you make that argument...........but, who would actually do that?

Mine Pulls Wonderfully Even As Low As 1500 Rpm. With The 4 Spd I Can Drive Around Local Roads In 4th At 30 Mph. I Am Going To Try To Find A 190 5 Spd And See What I Can Fab Up To Make It Work. Im Confident I Wont Have Any Trouble Keeping Highway Speeds At 2200 Rpm In My Coupe. I Am In Fla So There Are No Hills To Speak Of

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

If the road is perfectly flat, you can maintain 60 mph at 1500 rpm. It only takes about 20 hp to manage that. The problem occurs when you wish to climb the slightest grade...........or accelerate the vehicle. There's no power for either mode and you'd need to effect a downshift to make it happen.

The same way people say its more efficient to run a 4-cylinder hard than to loaf along in a V8.

Umm, say again in English please? Meanwhile bottoming out the gears actually stresses the engine harder than rolling along at optimum engine speed. And with complete diesel combustion reliant on compression and heat for cleaner burning, strikes me as obvious that bottoming the gears is last thing you wanna do - particularly with the 240D m616 which is what this thread is about.

Umm..........look up the information in the post.........if you're unable to comprehend it.

"Bottoming out the gears" is another factually incorrect statement.

"Stressing the engine harder" is another factually incorrect statement. You don't have any understanding of stress.

i dont plan to lope or lug the engine. looking at all of the HP/torque/rpm graphs I have seen the torque curve for these engines peaks in the 2200 rpm range. while it might be more responsive and fun to drive in the 3000 rpm range, for my purpose, high MPG, it seems like the 2200 rpm range is better suited. i am in an area with no hills and zero elevation air density. If someone out there knows where there is a 190d 5spd transmission and shifter available please let me know. i experimented with this around town and my particular car in my situation pulls very well between 1500 rpm and 2500 rpm in 4th. i see no reason it shouldnt do nearly as well in 5th.

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)