Originally Posted by
KnifeEdge_2K1
bhp/l is one of the best measures of efficiency
gasoline has a set amount of energy per litre, the engine is designed to harness this, if it cant harness as much energy per litre of engine displacement it means one of or both these things, 1 it is loosing more energy (comparitavely speaking) during combustion, or it isnt getting as high volumetric efficiency
however you look at it, the lower bhp/liter the less efficient the engine
you're just trying to find random arguments now, so off topic you it's not funny. the whole point was american engines are inefficient, and that given the same engine a european company would easily be able to tune it to give more performance. you then brought up the fact the cars those engines are placed in cost 10x as much as the base cars, i merely stated that the price difference is not attributed to the extra tuning of the engine, but rather set by demand and supply forces.
next time you decide to voice your opinion, straiten out your facts and argument
Unfortunately you are wrong yourself.
HP/L is a very iffy number that actually has little value on it's own. Take for example the rating of one of the worlds most efficient engines. it can achieve over 50% thermal efficiency but only has a HP/L rating of 4.27HP/L that is really low and would suggest a low efficiency engine to you. A much more usefull measurement that will tell you exactly what the efficiency is brake specific fuel consumption (rated in lbs/hp/hr or pounds of fuel used per horsepower per hour) the same engine I have been talking about gets a surprising 0.260lbs/hp/hr whereas car engines get between 0.385-0.600lbs/hp/hr.
When you look at america V8s and their BSFC then you see that they are infact pretty efficient and surpass many european and japanese engines. You see you forgot a few reasons that could lower HP/L ratings without decreasing efficiency (Like peak rpm, whether the engine was tuned for power or economy ect.)
High HP/L ratings normally indicate a lower efficiency engine, think about it if you make more power in a smaller space more waste heat is generated and to get higher peak HP you normally need to rev quite high which leads to increased friction and other mechanical losses.
In the end HP/L is a useless rating for anything other than specific power.
In the end americans don't make bad engines they just use displacement instead of technological advancement...
Last edited by hightower99; 06-27-2006 at 01:29 AM.
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.