1984 318i m10 Fuel mileage? HELP from the People driving M10's!

[BMW M-Phan]

I have 3 pretty simple questions...
How many Mpg do all the people driving an m10 1984 318i get? (I'm only getting approx. 17-19 mpg) :(

Can Loose valves make your spark plugs burn or blacken or leak oil or even burn oil? ( My spark plugs or fouled and carbon built black.) Theres got to be a fuel leak or something.

Can fuel injectors from an 86 or 87 325 e or es be used in my 318i? I don't know the flow rates and specifications.

The strange thing is my 318i runs good idles nicely at 850rpm. Pass emissions DEQ almost perfectly so I assume the fuel mixture ratio is good. But my car just has bad gas mileage In my mind.... I've read and heard stories where 318i new got around 30 mpg and up. and that a 325i or 325e was able to go on a full tank of gas up to 300miles and up easily.... I feel really disapointed if my car isn't getting the fuel mileage it should be so someone please correct me if i'm wrong about what kind of mileage my car should get?

[Holland]

What diff are you running? I'm running a 3.73 LSD in mine but I still get about 24mpg, I also do have to run it a bit hard and I do downshift.

[BMW M-Phan]

My car is all stock. I think a 2:93 open Diff. 318's are supposed to get pretty good mpg yeah? where can I find specifications? anyone know? I don't think e30world specs are accurate....

[Holland]

IIRC 84's had a 3.64 open diff. My 85 had a 3.91 open from the factory, 3.73 is a good compromise.

[e30mybaby]

i have a 85 318i and i get about 20-22! not good!

[BMW M-Phan]

@E30 Yikes not so great either huh...
@Holand Oh thanks well now I know what Diff. i have. Isn't the larger the case the better? Do you know what cars come with a LSD stock? where do people even get them?

[Good & Tight]

I have 3 pretty simple questions...
How many Mpg do all the people driving an m10 1984 318i get? (I'm only getting approx. 17-19 mpg) :(

Can Loose valves make your spark plugs burn or blacken or leak oil or even burn oil? ( My spark plugs or fouled and carbon built black.) Theres got to be a fuel leak or something.

Can fuel injectors from an 86 or 87 325 e or es be used in my 318i? I don't know the flow rates and specifications.

The strange thing is my 318i runs good idles nicely at 850rpm. Pass emissions DEQ almost perfectly so I assume the fuel mixture ratio is good. But my car just has bad gas mileage In my mind.... I've read and heard stories where 318i new got around 30 mpg and up. and that a 325i or 325e was able to go on a full tank of gas up to 300miles and up easily.... I feel really disapointed if my car isn't getting the fuel mileage it should be so someone please correct me if i'm wrong about what kind of mileage my car should get?

I have a 84 and it gets 30mpg, yours should do the same but everything has to work properly.

Valve adjustment is important the way the engine runs, so for starters warm up the engine and adjust them to .008.

New cap, rotor,fuel filter, air filter, NGK-BP6ES spark plugs set at .028.

If it idles smooth and passes emissions your injectors should be fine.

Timing is very important on fuel economy, I would deff check that and adjust it to factory spec or advance it just a touch.

ICV check to see that's working and not completely closed.
Check your fuel pressure along with the FPR.

I don't know the mileage or history/condition of your engine but if it's in decent shape you should be able to tweak it back to better MPG.

Just check the basic stuff first, valve adjustment and timing and go from there.

[BMW M-Phan]

@ good and tight. GeeThanks for the reply! I was wondering about the timing also.... can my car run as good as it is with bad timing? How to rule out bad timing?...
I have a few months old bosch wr9dc coppers that are burnt. they are in my pics if you want to see! Do you think i should stick with them? I gapped them at .034.
I'm afraid that my injectors are leaking after i turn off my car. when i start my car in the mornings it smells like fuel for a moment then i goes away after approx. 10 secs.

FPR(Fuel pump regulator?) is next to the fuel pump correct?

[BMW M-Phan]

Also can an improperly adjusted valves make my sparkplugs black and burn oil?

[Jaxx_]

Also can an improperly adjusted valves make my sparkplugs black and burn oil?

not burn oil, but it's very possible that improper valve adjustment can cause issues for the combustion process.

I don't know how my 318 does on gas, but from what I remember I did 25mpg on the highway with L-Jet and a 3.73 diff coming back from the mountains(still fairly hilly country)

[Hey_You]

I'm getting pretty crappy fuel mileage, but I have been messing with my timing to get a bit more pep out of it, to me, the loss in mileage is okay if I don't have to run at 4500rpm's everywhere. I too also smell fuel when I first start it up when it's cold as well. Pretty sure I need to adjust my valves here too

[ruppcam]

I get about 25 to 30 depending on how light footed I drive.

[DJ W]

i get atleast 20 i fill up once a week and i smash in my car i have a weldid 3.9 and yellow top injectors idk what pound they are

[Javier h]

24 mpg combined (both highway and city). On these things you need to redlibe to squeeze what little power there is.

[jeswaw]

I got 32mpg, but I drive my M10 like a grand ma out on the free way. I get about 25mpg on the back roads ;) But I just swapped it with a M50, wished I would've swapped my M20B20 car with the M50 instead of my M10 car. I loved my M10.