Fuel strategy is based on estimation for percentage fuel consumption of the fuel tank capacity per lap. Therefore this system forces me to calculate all of the inputs that I have mentioned in previous sentence. There are various estimated fuel consumption ratios for each car depending on tracks. We can rename these ratios as multipliers. Via these multipliers, LFS can calculate requiring fuel levels instead of us by entering X laps.

i.e:
I consider the 60 laps race as the integrity of 60 laps race with varied lap periods. In every pitstop (assuming 2 pitstops) I must calculate the percentage with a fuel consuming table. But via my suggestion, we just enter the number of laps.

Fuel load at start: enough for 24 laps
Fuel to add in pitstop: enough for 20 laps for 1st, enough for 16 laps for 2nd pitstop

And of course in F12 menu, we can see the fuel remaining as lap based.

Consequently, LFS will be more user friendly by this way. I suggest "Lap based fuel strategy" as an option (similar to psi/bar option), because of time duration endurance races and other cases.

+1/-1 with reasons please

Thanks..

I would say +1-1 = 0 for me.

I don't dislike the idea, but you can calculate this before the race like : x% for 1 lap --> 20x% for 20 laps and check the ratio each time. While you are on the straights or on a slow paced laps you can adjust the amount to the precalculated one.

I would not mind this feature in LFS but I am fine with this now

EDIT : Plus, it is better to calculate by percents instead of laps, because if you set your fuel for a certain amount of laps, and if you have to change your pace according to the circumstances of the races, you might end up without fuel or not adjusting your pace which will result in losing position.

What I would like however, is the ability to put some 1/10 of percents so that if you wish to have more fuel to cope with unexpected situations, you are not obliged to put 1 more percent as a backup which can mean 2 or 3 laps depending on the combo and adding extra weight for nothing

Fuel consumption in LFS is already far too simple. Real racing cars normally have no idea how much fuel they have in them, those that have a capacity to refuel mid race will often only have a low fuel warning light and when a guage of some sort is fitted it usually acts in a bizare non-linear way and normally only on the lower fuel cell. When real racing cars run out of fuel there is often no warning, proper fuel systems always hold about a litre in an anti-surge tank meaning unlike road cars they just stop dead without warning.

At the moment in LFS we know exact fuel consumption and never have an excuse to run out, which takes a lot of the guessing out. If we had to rely on a warning light and conventional guage it would be much more challenging and people wouldn't be able to cut it so fine.

Thanks guys for comments,

As you mentioned, in real race car the pilot have no chance to know the fuel remaining in tank, except for the tank is empty. In LFS an average fuel consumption (ATM time based linearly) ratio help us. But it's not given proportion. i.e: If your clutch was damaged and you must drive in 1st gear, the fuel consumption will boost up 3 or 4 times at least. So we can say that this feature is close to realism.

On the other hand the tendency that I observed in some LFS users is in line with demanding more precision about increasing the percentage decimals. And ATM, this approach conflicts with the realism.

I don't think adding percentage decimals is unrealistic.
Let's say, your tank can hold 60L of fuel and average measures shown that at a race pace you could do 10 laps with 10 liters of fuel.
The race is going to be 26 laps.
So : 1L = 1 lap = 1/60 x 100% of fuel = 10/6% (about 1.67) / 26 laps = 26 liters = 26/60 x 100% = 260/6% (about 43.33%)

You want to have a little more fuel to serve as a back up in case of some event disturbs your strategy, let's say half a lap, which is equal to 5/6% (just divide the first equation by half) about equal to 0.83 percent.
So the total fuel you will need to have will be 43.33+0.83 = 44.16.
With only one decimal (not centimals), it will be at 44.2% (approximative). Which means you have more margin of error, without having to add one more percent, which will help removing weight.

You guys might say that the variations are small, but this 0.8 less between having the choice of 44.2% or 45% can be very decisive during the end of the race.

(On a test track for the MRT, with between 15.5 -good lap- and 16 -bad lap- seconds per lap as an average, my laps were getting better by 0.1 seconds down to 14.8 for the 3 laps before I ran out of fuel. This might sound very small, but if you do the ratio between the two times before :
0.1 is 0.64% of 15.5 seconds
0.1 is 0.6245% of 16 seconds.

Imagine on the longer tracks (let's take a track that takes 1:51 (111 seconds to finish) in a fast lap and 1:55 (115 seconds) in a slow lap when you start) :
0.64% of 111 is 0.70 seconds
0.6245% of is 0.72 seconds.

Which means that with a very small variation of fuel (less fuel), you can end up having a time that gets better and better each lap (not by 0.7 seconds obviously, this is provided the tires stay at their optimal temperatures).
This was done on a track that burnt 0.14% of fuel per lap. Now imagine on a track that burns 1.67% of fuel (as stated before) per lap. if you have 0.8% of fuel less than the guy in front of you, this means you could be faster by some decimals of second per lap (as calculated before) at the end of the race, which can result in gaining a position.
This also means you could do faster "slow laps" times than the other guys and than your previous ones, ending in still keeping up and saving your tires for the final rush in the final lap.

Hi Zen321,

Thank you for very detailed explanation. I have no rejection for your examples. But let me state some points in order to clarify.

I mean by realism, "the real race conditions" , not "the physics rules". There is no doubt that, additional single gr makes slower the lap time. And according to the tank capacity, the quantity of the fuel taken does not equal to an integer quotient everytime. But we cannot determine this amount by 0.02% in real race conditions precisely. Just think about the fuelman in F1 pitstops. If the fuelman fills the tank longer by 0.14 sec and pulls back the hose 0.27 sec, all the strategy will collapse. The 0.8 sec. gap you stated before (lap based system = percentage system + 0.8 sec.) already includes the human rejection time lag. So, we can say that "the lap based system" seems more realistic.

And the MRT case. It's obvious the weight effect is more prominent in light heavy cars. But in road car and GTR car class (over 1100 kgs + 70 kgs standard LFS pilot) this effect is very slightly. As I know in F1 cars extra 1 liter of fuel causes 0.2 - 0.3 secs lap time loss according to the tracks.

My suggestion is an option such like as km/h - mph or psi - bar options. All I say that, LFS can calculate the fuel quantity instead of us and will be more user friendly. And finally, we say almost same things, but very slight differently.

Quote from ADX.14 :

Hi Zen321,

Thank you for very detailed explanation. I have no rejection for your examples. But let me state some points in order to clarify.

I mean by realism, "the real race conditions" , not "the physics rules". There is no doubt that, additional single gr makes slower the lap time. And according to the tank capacity, the quantity of the fuel taken does not equal to an integer quotient everytime. But we cannot determine this amount by 0.02% in real race conditions precisely. Just think about the fuelman in F1 pitstops. If the fuelman fills the tank longer by 0.14 sec and pulls back the hose 0.27 sec, all the strategy will collapse. The 0.8 sec. gap you stated before (lap based system = percentage system + 0.8 sec.) already includes the human rejection time lag. So, we can say that "the lap based system" seems more realistic.

And the MRT case. It's obvious the weight effect is more prominent in light heavy cars. But in road car and GTR car class (over 1100 kgs + 70 kgs standard LFS pilot) this effect is very slightly. As I know in F1 cars extra 1 liter of fuel causes 0.2 - 0.3 secs lap time loss according to the tracks.

My suggestion is an option such like as km/h - mph or psi - bar options. All I say that, LFS can calculate the fuel quantity instead of us and will be more user friendly. And finally, we say almost same things, but very slight differently.

Okay I now get your point better.
Well if it is like the psi-bar option, I guess it is not a big deal to implement it

However, I still want those decimals of % while not be able to have the same choice for the laps (only lap per lap, or half a half per half a lap, not by tenth of laps) I didn't mean the 0.0x level, but just the 0.x level, which is able to be determined. Also, the pitcrews in F1 series are highly trained professiona that try to have the maximum consistency in low times when having pitstops

I know i'm bitchy sometimes ^^

Quote from Zen321 :

However, I still want those decimals of % while not be able to have the same choice for the laps (only lap per lap, or half a half per half a lap, not by tenth of laps)

You haggle well. I will accept 0.5 lap feature. Deal? :Handshake