M20 more fuel Friendly

[rj1790]

Is there any way or thing that'll make my m20 more fuel efficient. I commute 25 miles a day and the m20 drinks gas. Any suggestions without having to do engine swap.


Thanks

[Wh33lhop]

Tune up (plugs/dizzy/valve adjustment), numerically lower diff (a 3.25LSD would increase mileage but it would feel slower), higher tire pressure.

[Sagaris]

ironing out the way you drive is the best thing you can do. I typically see 24mpg 50/50 freeway+city driving (325i automatic) but I have seen 30mpg and even then I had a few spirited runs which could have been nixed for even better mileage.

If you are a super-extreme gas pump hater and want to get risky and ridiculous then:

-Use a hotter thermostat
-Use thinner oil
-Use synthetic oil
-Overinflate your tires
-Remove excess weight such as the spare , back seat, and other items.
-Install skinnier harder compound tires
-Install incredible magnet to font bumper and latch on to semi trailers.

For the small gains it would not be worth the inconvenience and risk for me to do those things, but maybe you live on the edge :P

[jlevie]

The first thing to do would be to make sure the engine is running like it should be. That would include eliminating any intake leaks (find them with a smoke test), ensuring that the fuel system is operating properly (correct pressures and clean & flow test the injectors), valve adjustments, fresh air filter, fresh plugs/wires/rotor/cap, good O2 sensor, and ensuring that the engine is running at normal temperature with an 80C stat. The service life of an O2 sensor is not more than 100k. It is a scheduled maintenance item that will cause the engine to run richer as it ages.