I am thinking of taking the plunge and buying a 1991 350sd that is for sale locally with about 175,000 miles on it. I have had several 123s and know that if I bring another one home I will have to take up residence in the shed.

I was curious to know what kind of mpg these cars get. The EPA website says that is 24mpg on average, but I am interested in a "real world" figure.

Also, are parts a lot more expensive than for the 123 chassis 300d?

on my 350, i just looked at my log this morning. best mileage on a trip was about 24. i usually run 75. on a very long trip like to florida i would expect to do a little better. around town it is more like 17. some parts are about the same some are more expensive. it is a more complex car so more maintenance in general. but oh wow, when it is running it is sweet. it has a lot more torque than the 617 and many passing moves can be made by just squeezing the throttle wo a downshift.

definately not the bulletproof motor the 617 is, though.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

That's a stunning difference from the 3.0 engine, Tom. Many of us can get over 30 mpg on a trip with the 603.961 engine. It will typically drop below 30 at speeds above 70 mph, however. But, it will never go below 27.5, unless running on the winter fuel.

I'd have a heart attack if I only got 24 mpg on the highway. Why not own the 300 SEL, for $3K less money?? It gets about 21 mpg on the highway, and could probably be improved with a taller diff.

Do other 3.5L owners get as low as 24?

Tom, how do you manage only 17 mpg in town? I wonder how big of a brick Brian has under the pedal of his SDL to get 30 mpg. I haven't seen better than 25 driving like a narcoleptic, but 19 is as bad as I've seen with the kickdown switch in full lock.

Sixto
95 S420
87 300SDL

........LOL.

Well, I can't get 30 if I drive at 70 or above and I can't get 30 if the a/c is on, and I can't get 30 unless I drive it without shutting it off, but, normally, I can stay above 27 even with a bit of all of these negative factors.

Only about 5% of all of it's miles are "city" miles.

I have never seen less than 24.5 mpg, even with winter fuel.

But, please realize that this engine has about 130K on the clock. I'll bet that compression makes a difference.

Tangent time - I suspect my ALDA doesn't retract fully with no boost, doesn't extend fully under boost and is generally sticking. Is it possible to test the ALDA actuator extension profile? Are there specs?

Sixto
95 S420
87 300SDL

Can't answer that one, but, if it's any consolation, this one is an absolute slug at low speeds. I'm quite sure this ALDA has insufficient part throttle fuel.

However, correct me if I am mistaken, but the ALDA won't do anything for part throttle response until you get into boost. If you drive it conservatively (1900 rpm acceleration), the ALDA hasn't provided any fuel enrichment whatsoever.

I've got to put the boost gauge back on and see what it reads at a 1900 rpm steady accel. I'm betting it's zero.

When I was driving my 350SD, I usually averaged 27 - 28 mpg in all driving conditions. City driving did not make a measurable difference. Again, the diesel natural engine running characteristics help.

When she was coughing oil through at 50 miles a qt, maybe 23 - 24 mpg. 25 on the highway.

__________________
1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)

What is the current status of the 350?? Get it sorted out yet??

Hmmm...No. And it has been awhile, too.
Compression is shot is cylinder #1, but it can still start and run(not for long, as the local authorities may be displeased from the copious amounts of oil smoke). The only thing it's good for now is getting rid of bloodsuckers.

It is not worth much to get rid of, and it is hard to ever consider this car for parts. It sits in a heated garage for the time being. In the meantime I have two other cars I drive interchangably(the 300SE and the diesel). I am not hurting for space, so, whatever the future may bring.

Nothing new. That's why we all have more than one car. We can't afford to be dependent on a single piece at all times. I used to have 5 operating vehicles. Now I'm down to 2. 2 sold, and 1 sitting prior to present.

__________________
1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)

Ain't that the truth.

your benz is a 3 liter. so it should get better mpg. 5/30 better that is about what, 14 %?. i wish mine did better but, oh well. maybe i drive more agressively. i never drive less than 10 over on the highway and pretty much in town too.... so that is 75 to 80 highway.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

That makes a big difference with these, IMHO. Out here in the land of the ***holes, I normally don't ever exceed 70 mph. Most of our limits are still 55 mph. If you are doing 75-80, you are probably consuming 10% more fuel strictly based on the additional speed.

i am willing to pay the price. i rechecked my log and discovered that i was looking in the gal col instead of the mpg col on the second page. i discovered that i have a high of 26.2 on a trip and low average closer to 18.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.