
Characteristics of Fuels
 Density  Calorific value  CO_{2}  RON  MON 
Premium 95  0,75 kg/l  42,3 MJ/kg  73,3 gCO_{2}/MJ  95  85 
Ethanol  0,79 kg/l  28,4 MJ/kg  67,4 gCO_{2}/MJ  111  94 
Methanol  0,79 kg/l  19,9 MJ/kg  69,1 gCO_{2}/MJ  114  95 
LPG  0,54 kg/l  46,0 MJ/kg  65,6 gCO_{2}/MJ  94111  9096 
CNG  0,01 kg/l  45,1 MJ/kg  60,8 gCO_{2}/MJ  120130  120130 
Diesel  0,83  43,1 MJ/kg  74,4 gCO_{2}/MJ   
Biodiesel  0,88 kg/l  37,6 MJ/kg  75,3 gCO_{2}/MJ   
These value originate from the VWworks. However, only those most important for this page have been listed. The first column lists the densities of the various fuels at 15°C. Here of course, natural gas is conspicious.
If one puts the higher calorific value of natural gas against that of premium 95 fuel and takes the density into consideration, then according to this spreadsheet, the energy content of 1 kg of natural gas, corresponds to
that of 1,45 liters of premium fuel. This means, that at the filling station, the price of a liter of premium fuel can be compared to the price of about 2/3 of a kilogram of natural gas.
Bivalent engines don't exploit the high octane ratings. 
Indeed, the engine must be able to exploit the enormously high octane rating of natural gas, whereby, if at all, this is only possible with the monovalent drive concept. If one compares, e.g., the high calorific value and
the small density differences between Ethanol and premium fuel, Ethanol 85 would have to cost approx. 2/3 as much as premium 95. However, the consumption, as far as a bivalent combustion engine is concerned,
probably varies even more, because the ResearchOctaneNumber of ethanol, 111, can under no circumstances be fully exploited.
Diesel: 13% lower consumption at the same CO_{2}. 
Have a look at how much the octane rating breaks down under the harder testingconditions of the MotorOctane Number. Another interesting aspect, is the comparison between premium
and Diesel fuel. Whoever puts one liter of Diesel in, has 35,77 MJ of energy more in the tank, compared with a liter of premium, which 'only' gives 31,73 MJ. There you have it again, the difference of almost 13%, the
exact amount that is reflected in the CO_{2}emission.
Pure biodiesel would hardly have been worthwhile, even if it were allowed. 
To end up with, let's look at the values of biodiesel. By the way, what can be seen here, are the variations which are richest in energy. Although biodiesel weighs 6% more in the tank, one has more than 8% less
energy because the energy content per kilogram is much lower than the density is higher. Apart from that, it's CO_{2}emission per liter is also higher. This is only largely compensated for, by the fact that
during it's production a respectively large amount of CO_{2} was used up. 09/13

