How the $%$## do you get 30 MPG?
 

I have an 86 SDL, and I have read repeatedly about people getting 28-30 MPG. I get 22 religiously. Are these people lying, or do I need to do something? The air filter looks good, but beyond that I would not know where to look. Since I am new to diesels I would appreciate the help.

Oh, and I did a search, but searching for MPG or mileage brings back about 1000 different threads that seem completely unrelated. If you feel so inclined I would also take some pointers on how to search for the answers. I don't want to rehash all the same threads over and over again.

I guess they roll down hill, with a tail wind. The trip to and from the destinations are always downhill...Just a guess. I get 28 in my 300D, and that is if I keep my foot out of it.

now i get 28-30 with my sdl but i have no ac It gets as low as 25 in the winter. My fathers sdl seems to hang 24-26 year round with working a/c
Dont ask me just the way it is

28 mpg highway?

I get 22 city since thats all I drive and I romp on it

Yep, Highway. Since I live in the sticks, I do not have to endure citiy driving very often. When I do have to do city driving, the mixed result is 24 mpg.

trip from Maine to Virginia I consistantly got 25mpg+ at 75-80mph, and i have an injector that isn't popping correctly.

I'm assuming you've adjusted your valves, checked for timing chain stretch, and checked your timing??? Valves can be a biggie.

Many cars from that era have major problems with the accuracy of their odometers later in life.

Someone who confirmed their 30mpg using GPS would be impressive, although I would still be dubious as my E300 which is 2 generations newer technology only manages 31mpg combined city/hwy and it is mucd more efficient areodynamically and drags around less weight.

Valves, change the diff fluid, make sure the tyres are inflated. With one of those BigBoys, you should be near 26-ish.n If you;ve never run any cleaner through the fuel system, its not a bad thought.

Remember, you wont get the 700+ miles on 20 gals that we get with our smaller more "modern" cars. So keep your references STRITCLY to the SDL line with the big 3.5L engine.

Now Terry has me wondering if my odo is shot! I'll say this,. it got the best milage running straight D2 out of the pump, which rattled the heck out of the motor. With bio in the mix, it runs MUCH better but milage dropped slightly to jsut under 700 miles/tank. And then with the AC on ( lately around here), it dropped again, to around 30.

I get just over 20mpg city on WVO/Diesel mix. I can get as high as 25 on the highway.

went from 24.95 to 29mpg - 300SD
 

My 5 cylinder 300SD went from 24.95 mpg to 29 when I replaced the
broken odometer gear (the 12 tooth gear).

It had 10 teeth.
Funny, I was getting about 400 per tank, cruising speeds seemed okay.
I thought I was driving 66 miles to work each day.....

The 300D gets 25mpg consistently, odometer has no broken gears.
But that engine has no turbo.

Not having a 6 cyl engine like your SDL don't know what to expect.
But that timing of the injection pump is critical. Although, I have never
adjusted mine.

I too get baffled by some of the mileage claims. I used to be told that the
300SD would get 33mpg. Never seen that.

My ODO so far is correct. I have a 2 mile speedo/ODO check spot set up by the state of Texas on HWY 34 Between Quinlan and Greenville TX. It is not on my normal route, so every few months I go to Quinlan for lunch to do the test. I do not know if the ODO in my car was repaired or not. I do not have 1st owner records. 2nd owner records do not indicate any ODO repair.

redassag00 confirmed 31mpg on the trip to Centerville with his GPS in his 1987 300SDL.

i got 28 when driving 65mph for 9 hours.... i get like 22 in day to day life, dang city and traffic. but thats life

as far as searching goes, do not bother with the search function on this site.
Brian Carlton explained and approved method: http://www.google.com/advanced_search?hl=en use the advanced search link, type all the words you want to search for, then restrict the search to www.peachparts.com Domain.
perfect searches every time!

Sheeesh thanks for the tip! I was feeling like captain Tard Boy in my searches!

Oh, on topic..... 28 MPG 300D turbo