Bmw 540i/6 Eco-modding

[Tulok]

Oh yeah, the maintenance is covered on this bad boy!
Performance for me comes first, I'm sure the 180 treadwear tires aren't helping gas mileage. I'm also doing a ton of other mods that will not reduce gas mileage though. vented hood will help drag considerably. slotted rear bumper to reduce the parachute effect. possibly spacing out the back of the front fender to let air escape. Lowering it further down. windshield wipers are gone. I'm planning on doing some minor weight reduction:
oem 46lbs hood
oem trunk 30 lbs
jack 7lbs
spare tire 41 lbs
208lbs old wheels and tires
182 lbs new wheels and tires. (26x4= 104lbs calculated weight loss)
old exhaust: 90lbs
new exhaust: 18lbs
floor mats 7lbs
front bumper support 27.27
rear bumper support 50lbs
rear sound insulation 20lbs
Trunk interior 35lbs
Engine Cover 5lbs
Hood Insulation 3 lbs
Washer reservoir 8lbs
wiper blades 3lbs
Both front seats + rails 252lbs
Rear Seat 80lbs
rear seat belts 8lbs
steering wheel 9lbs
A/C 32lbs
Sunroof w/ motor 23 lbs

You should look into slotting your cam gears and adjusting your cam timing to really promote low RPM torque. you could also switch to a 1988 528e ECU, but you would lose horsepower quite a bit and it might not work out quite right. I think a pan to bridge the gap from the gas tank to the bumper would help a lot on this car. The front cold use a few pieces too, though I'm concerned about reducing hood pressures with an underpan without venting the hood.
Idk, I guess we'll find out what works!

[straight5]

With the grill blocked, do you think that maybe the engine gets warm enough for the ECU to richen the mixture?
Just a thought.

[Tulok]

A hotter engine would generally cause the ecu to lean it out more, hotter intake temps = less dense air = less fuel.
Probable no change in ECU parameters.

[ever_green]

i'm not sure about the older BMW but my dad's 135i hood slightly lifts at high speeds (75mph). This allows lots of air inside the hood and you can see the intake air temps drop dramatically with scangauge.

[straight5]

hotter intake air temps = leaner for correct mixture.

If engine heat goes high, ECUs richen the mixture to help cool the engine.