Increase fuel economy on 84 300d?
 

Is there any reasonable way to increase the fuel economy on an 84 300D without harming the engine or any subcomponents? I would be willing to greatly increase fuel economy even at the cost of some engine power.

How much do these diesel engines depend on fuel to cool them?

Thanks for any ideas,
Aaron
(proud new owner of a 300D)

Re: Increase fuel economy on 84 300d?
 

Aaron - how many miles on your 300?


keep your filters clean and your fuel coming from a 'good' source. try different sources in your area and keep a record of the economy to determine which one is best.
higher ambient temps are also a help.

another thing is you can try to keep the car light - as in not use the trunk as your garden shed , lol :D

i would say that the engine does not use fuel to cool itself , not one bit.
:confused:

It's got around 250,000 miles on it. No blowby, new fuel distro, new fuel lines, new fuel filter.

So there isn't some screw I can turn to reduce the amount of fuel getting squirted in there? Or there is, but there are negative effects besides power loss?

I just couldn't hold out for a decent 190D 2.5 or Turbo with better fuel economy, plus I love the styling of the w123 much more. I guess we'll see what kind of mileage I get outta this car.

increasing fuel economy
 

one fairly easy way(if, you're handy with a wrench) is to drop in a rear end from a 1985 300D . or a wagon , etc:-
The 2.xx ratio will give you not only a higher cruise speed, but also a good 2 mpg gain. Plus, the car wont be so 'buzzy' at highway speeds

It really is a bloodless bolt-in, 1 hr at most.

think you could turn down the alda a bit but not sure it would help.

how about the air filter? it could be really dirty which could affect your fuel economy..
would check and replace if necessary.

Three things:

Good alignment -- too much or too little toe will kill you.

Raise tire pressures to 32 psi all round, use only good radial tires of the correct size (or a bit bigger).

Make sure the brakes release properly all round, espcially the rears, as you won't get any "feel" if they do, only less performance. Jerky stops are a sign you have stuck pistons in at least one caliper.

And, most importantly, drive like an old lady. Diesel use much more fuel when driven hard -- gentle acceleration and long coasting stops save brakes and fuel. Keep it under 75, perferably under 70 on the highway, too -- they love to go faster, but use significantly more fuel if you do.

Peter

I think another way of saying what the accumulation of posts so far is..... try to keep the car as efficient as you can . The MB diesel is already amazingly efficient... if you just learn to practice the kinds of things mentioned......that is the best way to get good mileage and have the engine last as long as possible....
Some claim that using Synthetic oil will help on the mileage.. and it may ... but too often using it is used more as an excuse not to change oil as often.... and I am a believer in DRAINING the stuff out of the system.... so I use Delo400 and change often...

Follow the good suggestions above, keep a clean air filter in the car, and realize that the most important factors in fuel mileage are weight and driving style.

Good luck,