Firstfives.org

Not that it matters large, I've noticed I'm getting 12 m.p.g. in just about all short trip neighborhood driving. Just curious what I'll be checking out come spring to improve things.

Installed a new 02 sensor. Can't be the fix, but all of a sudden the Nemo on the '79 quit searching during warm up. Every part and piece from injectors that have always worked, I've run cleaner through them, to correct timing, valves adjusted, no smoke, no noises, new Bosch WR9DS plugs, new distributor cap and rotor, new plug wires, rebuilt throttle body, switches adjusted,...the car runs great by all I know.

Run 87 octane, no pinging. Cold start, sometimes below ten degrees, runs about 850, climbs to 1800, hangs for two or three minutes then drops. Depending upon how late I am I like to imagine any heat is helping the transmission warm up to shifting.

So, is the fine tuning for max m.p.g. going to be in the AFM, throttle body needles ? I've heard of fancy air metering tools back in the day.

I think checking the m.p.g. on local neighbourhood driving does not seem to be the best test. Is 12 m.p.g that bad for local? It will depend too much on how you stop and go. I would test highway fuel economy (check both?).

Just adding to the list of things to check if you have not. Make sure you have correct pressure in your tires. Pressure and type of tires can make a big difference. Did you check your points (you did when you set the timing?)?
I have heard on here that the thickness of oils (engine, transmission, differential) can make a difference but do not know by how much. With cold weather that could be enhanced.

I remember a thread on this forum a few years back and it seems that the city mileage that most of the Five drivers on here were getting was 12mpg.
That's just what they get.

On the 528 w/o I, I had about 12 - 13MPG, some less during winter.

I get a combined 17 mpg in my 528i with a Metric Mechanic motor with L-Jet. It runs quite rich, I have considered opening the AFM to see if I can do better.

I just filled up and did the math on my e12 yesterday. In two weeks of local city driving around town, I got 12 mpg.

Funnily enough, the fill up before that I got around 17.5 mpg, after a day of hard mountain, hills and coastal driving. I guess the car has spoken she prefers the speed and so does my wallet.

Short trips will kill the MPG, especially in cold weather. Hook up and monitor the O2 output, if it's good and dithering it's about all you can do. Hook it up and set it on the dash and drive around, you can run it in thru the passenger window just fine and roll it almost all the way up.