> Rick wrote: > https://www.unz.com/article/the-car-that-almost-was/
I am skeptical of the 170 MPG claim. I guess I know too much. Weight, drag, and size of the car are big factors. It's a LOT more than just an efficient engine. A W123 car with a 100% efficient engine would only get about 125 MPG. That is why the 100 MPG carburetor is a myth. Darn physics! But I did some number crunching using a spreadsheet I built a number of years ago relating to aerodynamics and fuel used. What I came up with surprised me. I think it's actually possible. With a Cd of 0.2 and a frontal area of l8 square feet [1.673 m^2]. That's a small car. But the engine has to be 45% efficient. That is _really_ efficient. But if it's hybrid, it might be able to because it runs at one speed - ie, practically always at peak efficiency. I went looking for cars that might be that small. And I found this list https://ecomodder.com/wiki/Vehicle_Coefficient_of_Drag_List ... and it _lists_ the L1!!! Cd of 0.15 and frontal area of 11 square feet [1.022 m^2] ! That is smooooth and small. But with those numbers, and a guess of 3000 lb [1360 kg] the engine can be 30% efficient. Not only is that believable, it's not very remarkable! Then I changed the accessories to be 20% cause with a tiny engine the A/C and such will be a bigger percentage. And with an engine achieving 35% efficiency - which is noteworthy, but not at all unbelievable - it could reach 170 MPG. Using the same values for the engine, but making the car heavier and with a larger frontal area and with a still smooth but more realistic Cd of 0.2 - 90 MPG is possible. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
