19 mpg...

[noypi2]

My M10 average 19 MPG for both freeway and city driving. PO put Gen 3 green top injectors. Would this be the cause of my high gas consumption? or its something else...

[packratbimmer]

L-Jetronic is not an adaptive fuel injection system. I would get some stock injectors and try them. A properly tuned M10 can deliver 35 MPG on the highway and 22+ around town. 19 highway is way down there - something is wrong.

BTW: Toss any weird plugs and use copper on the 318i.

[84driver]

I use newer 4-hole injectors (Mk3 2.0L Golf injectors, VW #037-906-031, Bosch #0280-150-955) and get the low to mid 20s, which is reasonable for how I drive. Is your O2 sensor busted? Have you checked the AFM? Does it smell like it's running rich?

[noypi2]

My M10 average 19 MPG for both freeway and city driving. PO put Gen 3 green top injectors. Would this be the cause of my high gas consumption? or its something else...

Forget to mention...its autotragic too..

[packratbimmer]

Still too low especially on the highway. Question: Any other non-stock parts on the car or just the injectors?

Opinion as follows:

BMW had the 318i tweaked for efficiency in those days (think 325e/eta). Any changes on the non-adaptive L-Jetronic are likely to be a tuning challenge and cause a loss in MPG. It can be done for sure, but a professional fine tune will certainly be in order. Back in the day, I found that advancing the timing and running 93 octane resulted in more MPG, but I had the domed higher compression pistons (not sure if that matters). Having said that, injectors could certainly be a factor. Newer injectors like so many other technologies have their own "signature." They likely atomize the fuel differently at the same flow rate, open and close faster/slower etc.

I would suggest going stock and making one change to the the engine and management system at a time.

[noypi2]

Just the injectors. Thanks for the suggestion. Anybody here have injectors available?

[packratbimmer]

See if MEPEH has any. They need to be clean and in recent service.

[jonnywadster]

Mine got horrible gas mileage until I did a full tune up. seafoam, plugs, wires/cap/rotor. all fluids new air filter, and a new fuel filter.

Start with the basics.

[noypi2]

Did all that except seafoam..still low MPG.

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[thebutterson]

I have a set of stock injectors. They seemed to work fine before I pulled them. PM me if you're interested.

[packratbimmer]

30 year old injectors will need cleaning!

[Javier h]

M10 = 24 mpg

Period

[Smelser]

Rock auto!!

My M10 gets a gallon of gas each week and does anywhere from 10 to 15 miles. but I am racing it at 7 thousand rpm.

note, uses about 3/4 of the gallon, every 4th week I dont need much gas , just to be safe