kspacc

Wow. This forum is clearly not about the game. Anyone who has played this game from the beggining knows they have reduced the efficiency of the fuel/engines repeatedly. The ion engines used to be the same ISP everywhere, you used to be able to make flyable planes with them. And the jet engines used to be able to travel more than three times further w ith the same amount of fuel. They have been reducing the efficiency more and more since first creating the game, and there is no possible debate about that. There is no reason to be leaving any comments here if you are not interested in how the game works or in helping to improve it or you don't understand what Delta V is. Please ONLY leave relevant informed comments on this post. This post is about why they have reduced the efficiency, and looking for REALISTIC ways to measure and compare the fuel to real life aviation fuel. Obviously it is not enough to just say it is 5kg per unit, as that has changed many times over the last few years.

No, because they ARE underpowered and I am suggesting making them sensibly powered. And if you believe it is arbitarry then it would not matter. The ONLY sensible argument was that the planet is smaller so they seriously reduced efficiency, but seeing as the game is not limited to the small planet that still does not make total sense. The fact is that in reality they have given us 200 units of fuel per ton, which seems to be the equivolent of only 200 Litres, when in reality it is 1,250 Litres of aviation fuel per ton.

That is nonsense. Reducing the weight of the fuel would in no way have any of the effects you have claimed, it would simply be more efficienty and increase Delta V.

1 ton is 1,000 kg, which in reality is 1,250 litres of fuel, and in the game it is ONLY 200 units, there is no getting away from that fact. You don't need a TWR of 1+ for a non VTOL, so a 747 doesn't need a KN of thrust per Kg of weight. And you can see clearly when playing the game that planes can only fly a short distance on a large amount of fuel compared to in real life.

Exactly! A 747 with 4 engines burns the same amount of fuel as ONE small to medium jet engine in the game. The discrepency is about three fold, even if you round everything up, and allow for it not being Earth. ONE normal sized jet engine used in a small 1-2 person aircraft that can't even carry half a ton can use that amount of fuel to fly thousands of miles in real life, and in the game half a ton gets you to the small island and not quite back, when it should easily get you to the desert airstrip. They have made a fuel unit larger than a gallon, and made it less fuel energy than half a gallon. True, but the orbit science in this game is pure fiction anyway, so I just ignore it. In reality NOTHING just hangs in orbit needing to be pushed back to earth, it takes constant energy to stay in orbit as it does in any flight, and the second that energy stops being expended the object is pulled back out of orbit towards the planet. Come on mate, this is trolling! We are talking about reducing the weight of a unit of fuel in the game. DO NOT post another reply ignoring what the discussion is about or dismissing us being allowed to have that discussion please.

Which ever way you measure it, compared to real life either the fuel or the engines are extremely inefficient. A ton of jet fuel goes a long way in real life, in the game it is barely enough to get one engine such a small distance you wouldn't even bother flying in real life.

That is reducing fuel, which is it's own variable in Delta V.

Sure, but 5kg is a lot, that means you are burning 1kg-3.5kg per second minimum in the medium sized jet engines. And a ton of fuel is hardly any fuel in this game, in real life a small 1-2 man plane can't carry anything like a ton of fuel and can travel a few thousand miles easily. I remember the Oscar-B tanks, they have been in the parts list since long before this game was released, but if a unit of fuel is 2.5L and weighs 5kg you can surely see the problem, that is only 500 litres per ton, when real-life aviation fuel is 0.8 tons per 1,0000 litres more than twice as much for the weight.

No, the fuel itself, compared to real life. Aviation fuel for jet engines weighs 800kg per m3(1,000 litres), in this game you get 200 units to 1,000kg (1 ton). So if as OHara said 1 unit is 5 litres then the jet engines are buring 1L - 3.5L per second! No-matter which way you look at it, they have made either the fuel or the engines really unrealistically inefficient.

Yeah but they set Kerbin's gravity to be almost the same as Earth's, and it is really a huge amount of difference compared to real life how much fuel a ton is.

Mate, were not talking about amounts of fuel. I am talking about how the fuel is set to be so heavy in the game compared to real life. In real life a ton of fuel is a lot of fuel, in this game it is barely enough to get a jet engine to the nearest island and back. Please, stop replying talking about amounts of fuel and Delta V, this is about how the game is set-up. And it would increase Delta V anyway , because the same amount of fuel would weigh less if it were more realistic.

They change THIS area of the game in almost every update, it would effect NOTHING more than usual. And we KNOW what the grav rating is on kerbin, it is the same as Earth. I have been playing this game since it was an unreleased piece of software with virtually NONE of the same parts it has now and NONE of the same physics. If I updated to the latest version right now there would be changes from the one I did last year. Can't see how making it more efficient to be more realistic would upset anyone, they make these kind of changes all the time. I have never noticed the ladders being draggy, is that when you use more than one or something?

I wrote a huge long explanation, why could they not just have let me submit it? Ridiculous website. ANY reduction in weight INCREASES Delta V. We are NOT talking about changes the AMOUNT of fuel, it is very simple. This page is NOT about assuming we don't change the game details, it is about assuming we SHOULD to make it more realistic. I am suggetsing they use aviation fuel as model for the weight and efficiency, as that is what jet engines burn. Aviation fuel weighs 800kg per m3. You can't take both weight and volume out of the equation, or you are not calculating anything. A ton of aviation fuel is far more than a small plane could ever carry, so it CANNOT be only enough to travel a few miles. They have been syetmatically reducing the efficiency of all the engines in the game over the years, you used to be able to make ion olanes that flew, now they are reduced so low you can't get any thrust, so it is not fixed or based on anything, and if it is arbitrary then there is no reason not to make it more realistic.

Yes, 5 litres of fuel per unit makes sense. But its still a bit heavy, because aviation fuel weighs 800kg per 1m3. So it should only weigh 1.6 tons. And it does mean that most of the jet engines burn over 4 litres a second, which cannot be realistic, surely?

I'm talking about reducing the weight of the fuel, not the amount of fuel. ANY reduction in weight INCREASES Delta V. You are talking about reducing the amount of fuel, NOT the weight of the fuel. This page is about working out what is going on with the units of fuel in the game, because they don't correspond logically to litres or gallons. OHara has explained how the numbers match up roughly, but there is no explaination of why they made a unit 5 litres, 4 litres would at least be an American gallon, which would at least have made some sense. This explanation does also mean that the engines burn a lot of fuel, which still suggests to me that they might have been a bit conservative with the Delta V.