[Notary Sojac]

One thing that some people can do is reduce the weight of the engine by trying to see if their engine can be retro fitted with aluminium cylinder heads. That there alone can reduce at least 50 to 75 pounds of weight.

How expensive would gas have to get for this to pay off?

Let's say your car currently gets 18 mpg, and that it would cost $1000 (on the low side) for the head replacement, and removing 50-75 pounds of weight would improve gas mileage by 3 percent (I think that's generous).

With gas at $8.00 a gallon, you would have to drive 80,000 miles to get your thousand bucks back. And you wouldn't want to swap out heads until your existing engine was out of warranty, right? So better be prepared to put 120,000 plus on her.

How expensive would gas have to be to make this deal pay off in a more reasonable 50,000 miles. Between $13 and $14 a gallon. And at that point we'll all be driving Fiat 500s anyway.

I love to run the numbers for people.......

[nascarnation]

You’re using basic math and logic.
Is that still allowed on FR?

[American Constitutionalist]

If someone were to be mechanical inclined that has aluminium heads laying around then yes, that would pay off.
I read somewhere that for every 100 pounds of reduction of weight from a car you can get 2 to 3 % boost in the MPG.
Wonder if they can make plastic casings for AC compressors, alternators, that can withstand the heat and just as strong as metal casings ?
How about the weight of a full tank of gas compared to 1/2 a tank of gas ? 1/4 tank of gas ?
What would the numbers be then ?
I know 1 square foot of water weighs about 64 pounds so ? what would 1 square foot of gas or the volume of a full tank of gas weigh ?