Quote:
Originally Posted by mort
Hello elemein,
First using 20% throttle and 80% VE is a bit unclear. VE generally means at full throttle. Assuming you mean to find the amount of fuel used at 20% throttle, and also assuming that 20% throttle means that the amount of air (mass of air) being consumed is 20% as much as would be consumed at full throttle, then your math is fine. Assuming 20% as much mass of air makes everything easy, you consider that the air entering is about STP and the density is about 1.2 gm/l So 200 cc (20% of 1l) is 0.24 gm of air.
0.24 * 1000 (rpm/2) = 240 gm per minute. at 15.5:1 A/F gets you 15.4 gm/minute, or 929 gm/hr of fuel. What speed is this Metro making at 2000 rpm? Is that likely 50 km/hr? 929/50=18 gm/km. The density of gasoline is about 750 gm/l so 0.025 l/km or 40 km/l (about 100 mpg)
Or is that 2000 rpm and 20% throttle closer 10 km/hr? Or 100?
-mort
|
This math sounds similar to the math made in my previous post; is my previous math correct?
I am not sure what speed the Metro is making at those conditions; I am just sortof making up conditions and it just so happens that the Metro happens to have a 1.0L engine and fits this situation oddly well...
Nonetheless; thank you very much! Your posts have made complete sense and are quite concise. I understand this subject much better! Thanks again!
