Adding a new unit of measurement like this is sort of like adding a new gear to a transmission. It involves touching just about every file on the site, and adding hundreds of lines of code. We'll consider it, but it is something we'd need to dedicate some serious time to, so this likely won't be added in the near term.
I know this means the site isn't very useful to you, sorry about that. You might see if there are some similar applications built specifically for India.
L/100k seems alien at first to someone who grew up with mpg, but in a way it makes more sense. It makes the concept of cost for a trip a bit more accessible mentally. If I know that I'll have to replace X numbers of liters after making a trip, I can more easily assess the cost/benefit of the trip.
So dividing total trip Kilometers by 100 then multiplying that by the L/100K value to get how many liters for your trip is easier than dividing total trip miles by the avg MPG to see how many gallons it takes? (or the same of KMPL) Sounds like more steps, according to the math.
Maybe its easier due to having a 100k value as part of the division path, but from a step point, it takes two steps, instead of one.. That or I'm missing something simple.
If you are using this to plan a budget for before you take a trip is what I'm assuming here.. But I always budget for 1.5 times what I need. Cause ya never know how many side jaunts or missed turns you may take. lol
But oh well. Still think its just.. Odd, regardless of the reason.
We do support L/100km across the site, ggarnier, you just need to switch to the "metric" view to see it. It's a standard in many places including Europe, China, Canada, Australia and New Zealand—according to Wikipedia's article on Fuel Economy. We have a special UK view because the gallons are a different size and they sell fuel in liters.
And according to the wikipedia article on Fuel efficiency India and Japan use km/L. We honestly didn't know that when we set up the site, and we heard from more UK and Canadian folks during the early building phases of the site. That's why we have MPG and L/100km but not km/L. We've had a few requests for km/L and it is something we'd do in a perfect world, it will just depend on whether or not we can devote the time to it.