What is the normal rpm my 300D turbo(auto trans) should be turning at 65mph? Mine turns about 2800, is this normal? Thanks ,Jim

__________________
1985 300d Turbodiesel "Bessie"

That is a normal rpm at that speed. Remember.....that year was when the 55mph limit was nationwide.

(I also remember certain socialist politicians, at that time, came to Texas and were aghast when they realized that most folks around here just ignored it. )

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

Agreed, good rpm for 65.

__________________
83 SD

84 CD

Yeah on the 85 with the lower diff gears...2800 rpm is normal for 60 mph with the higher, pre 1985 gears...

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Yes, its fine.

Let off the pedal at 65 mph to see how much slip there is in the torque converter. There should be ~ 6% at 65 mph in average conditions. Tach, if accurate, should drop to ~2625 rpm @ 65 mph assuming wheels are equipped with stock rubber (195/65/R14's).

Most american cars of that era aren't really safe/capable of over 55 though...

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I generally run a bit over that 70-75 mph on the Interstate.....just a tad over 3,000 rpm.... Locally with these winding hilly roads in WV, I never get a long run at speeds around 65 mph.....

SB

Also of Note: According to the book MB book Technical Data Passenger Cars, April 1985 edition.....an '85 300D should get its best fuel mileage at 120 km/h or 75 mph.......

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

im running 70 mph @ 3000 rpm, so you seem to be right on the money.
shorebilly, where did u read that? if thats true, then im gona have to start speeding again

__________________
1983 mercedes benz 300D turbo diesel.
pyrometer, boost/vacuum gauge
exhaust dump pipe
turbo- 15 psi boost. 25 psi capability
disconnected EGR

The li'l grey book, Mercedes-Benz Technical Data Passenger Cars, page #47....Chapter 00, General Technical Data, Fuel and Engine Oil Consumption...

There are no entries for W123.133 (USA, Turbodiesel) but the figures for W123.130 and W123.193 TD Turbo are similar......

SB

Also of Note: Engine Oil Consumption, max. 1.5L/1000km

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Almost exactly 3000 rpm for me is 70 mph and about 2800rpm is about 65. Mine is an 85 300SD so it should be almost identical (mines a cali car other wise it would be identical).

__________________
green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

That seems to confirm what I have noticed. Mine might do a little better at a higher speed because I modified the turbo with a 50 trim compressor wheel.

__________________
green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

Seems a little high compared to mine. I also have an '85 model, and at 65mph I am running exactly 0 rpm..........

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

jimmy did you know your tach is broke?????

__________________
commercial fisherman diesel in my blood in my boats trucks and Dear old Dad has had me drivin them since i got my first license in 1968
1986 300 SDL 427654
1999 Chevy Crew Cab Dually 225423
1986 300 SDL 287000 Dad's
1987 190 Turbo 158000 Mom's (my inheritance)

Mine to! I still can't figure out how I only get 20 something MPG with the engine not turning.

After today's trip my mileage will be suffering though. After a 2 hour drive I only covered 0 miles according to my odometer.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine