[CuriousOne]

Hello, let me introduce myself/my situation.

My current and only car isn't very fuel efficient (due to what car it is and what I've done to it, but since this is an eco forum I don't really need to tell anyone details) and sometimes I want to work on it so I need another car sometime in the future, but I need this other car to be fuel efficient. The car I'm looking for doesn't have to be luxurious or anything. Just cheap and cheap on gas. Anyways, I'm not really looking for suggestions as I have some in mind.

What I'm looking for are modifications to the car that will be cheap and will give it better fuel efficiency, and I don't want the car to look ridiculous (meaning I don't want to do aero mods to it). Here were my ideas:

Warm Air Intake - I plan to position an open air element filter right on top of the exhaust manifold or very near it so the air is warmest and the air is the least dense.

Gut the interior - I don't really mind what the interior looks like, so I'm just going to gut it. Fairly obvious why I want to do this.

Remove Power Steering - In a light car, P/S isn't really required, so I'll just relieve the crank pulley of weight (for slightly more power) and relieve the car of overall weight.

Remove Air Conditioning - Relieves the car/crank pulley for less weight + more power.

Increase Tire Pressure - It might handle weird, but this will give me slightly better mileage.

Misc. Exhaust Modifications - Most exhaust components are made of cast iron (which is much heavier than steel, stainless steel, etc.), and some are crush bent and just overall very restrictive which creates backpressure. Backpressure in an exhaust system is never needed, so a well tuned combo of a header + exhaust could make the engine not strain itself as much while still giving it more power/torque, while still being an overall lighter system.

Any other ideas, or are the remaining ones expensive to do?