List of Factors for Fuel Consumption

[Mordan]

Hello..

I'm trying to list factors of increasing fuel consumption in old cars.
what are from your hands on experience DIY jobs that decreased/increased the consumption.

I would divide increased consumption into 3 categories

1) engine wear and engine tuning which leads to less power and more fuel consumed
worn piston rings, wrong valve clearances, fouled spark plugs,

2)fuel injection problem
old injectors don't vaporize the fuel as well anymore (will new ones really improve the fuel consumption?)

3) body factors
tyres balance and size, sway bar links, holes in the exhaust, too much weigh in the car (of course)

will the lack of fuel pressure be an issue? (fuel pressure regulator and fuel pump)

I'm reading somewhere ignition coil may increase consumption.... how?


thx