list of gas saving tips from best to worst

[theholycow]

Welcome. There's some good basic info there.

Here, we like to go deeper into those ideas. I can offer some additional insight into some of them.

* Don't "step on it" Drive with a even throttle(?) Especialy when going up-hull, and use the next one when going downhill.

That is a valid strategy. However, the opposite strategy can also work very well. I have had great success with opening the throttle a lot. I step on the throttle pedal hard whenever I can. I know that it has produced very good results for me, but to explain it I only have theories. Two of those theories are:
- Reduced pumping loss. For a certain amount of work the engine has to do, it has to move a certain amount of air. Whether it moves that air easily past an open throttle or with more difficulty past a closed throttle can make a difference in efficiency.
- Using the engine in its most efficient range. It can be measured and displayed with a BSFC chart (search for information on that). Most engines produce work most efficiently when heavily loaded. This may be because friction and reciprocating loss at a certain RPM is approximately the same whether it's producing a little work or a lot.

It doesn't work for everybody, but it works great for me.

*(my favorite) Let the engine do your breaking. Using your pedal is allways unnecessary. Letting your engine do the breaking can COMPLEATLY choke the fuelsupply(at about 1600-1200(lower for diesel cars)). When decreasing under 1200(lower for diesel cars) just gear down.

This is called DFCO (Deceleration Fuel Cut Off). As long as you need to reduce your speed, it's very effective. It helps to know the exact conditions in which your engine will DFCO, though; the programming can be very picky about when it will DFCO and when it won't. It is not as common as most people think.

Don't know the name again but "engine heater" gave 17 500 000 resaults on google so well use that:

We call it a "block heater".

* The AC uses up to 0.0264172 gallon(damn americans and your metrics system! haha) per 6.21371 miles. Well it's not that much but if you don't need it, don't use it. (this was converted from 1 deciliter per 10 km)

That can vary based on your driving. If you are driving in stop-and-go traffic, such as in a traffic jam or in a city, that's very true; you should open your windows instead. If you are driving steady at high speed (80kph and more), it may be more efficient to close the windows and use AC instead, because of the aerodynamic drag caused by the open windows.