Talk:Lotus Evora

Fuel consumption and emissions relation
About: Fuel consumption: ~9.4 L/100 km (25 mpg U.S.).[citation needed]

CO2 emission is directly proportional to fuel consumption. Each litre of petrol/gasoline produces ~2.4 kg of CO2 (for diesel fuel it is ~2.6 kg, mainly because diesel is denser than gasoline).

So, if Lotus claims a CO2 emission of 225 g/km, that is equivalent to 225g * 100 = 22.5 kg / 100 km. Since 22.5 / 2.4 = 22.5 / 2.4 = 9.375 l / 100 km. Or more simply, 225 / 24 = 9.375 l / 100 km.

If you check manufacturers specs for a number of cars, you will see that this relation holds for CO2 emissions versus fuel consumption for combined cycle (accounting for rounding). (I suppose there is a European standard somewhere that specifies that this the way the CO2 emissions are calculated.)

Example (2 Mitsubishis, just because it was the page I had open): Combined mode lts/100km (mpg) 	 	10.3   	  	8.0 CO2 emissions g/km 			246 		191 CO2 g/km / lts/100km			23.88 		23.875

(Note that in the result only 3 digits are significant.

It is also possible to get (approximately) the same figure starting with the fuel density (0.71–0.77 g/cm^3 for gasoline) (to get the weight of a litre of fuel, 0.71–0.77 kg), making the simplifying assumption that the gasoline is C8H18 (molecular weight = 114), calculating how many moles of C8H18 there are in that litre of gasoline (call that X = 770 g / 114 g = 6.754) and calculating that the complete combustion of those moles of C8H18 will produce 8 * X = 54.035 as many moles of CO2 which will weight 8 * X * 44 g = 2377.54 g = 2.377 kg.

For diesel the calculation is analogous, using the knowledge that "the average chemical formula for common diesel fuel is C12H23"(167g) and the density is 0.85 kg/l: 850 g / 167 g = 5.089, 12 * 5.089 = 61.077 moles of CO2, 2687.425 g CO2.

I had done such calculations a couple years ago and IIRC the figure I got was also approximately 2.4 kg CO2 produced for each litre of gasoline and 2.6 for diesel.

Rps (talk) 17:27, 23 July 2008 (UTC)


 * I assume you are defending your addition of the fuel economy number. However Wikipedia policy does not allow synthesized material or original research.  We will have to wait for the official numbers to be released.  Also, while fuel economy is directly proportional to emissions the proportion is not always the same from vehicle to vehicle.  One vehicle may have better catalytic converters or be tuned differently.  swa  q  17:45, 23 July 2008 (UTC)

Official fuel consumption and CO2 emmisions have yet to be release and so any figures seen beforehand should be taken as a guide, at best.

86.29.165.193 (talk) 16:41, 5 September 2008 (UTC)

Transmission
I`d love to read some detailed info about the transmission. Is it a Toyota-product too, which type is used? —Preceding unsigned comment added by 87.123.154.144 (talk) 09:11, 8 June 2010 (UTC)