so wait wait, your saying that rwd will get better mpg than fwd because it allows for a smaller frontal area??? that is a stretch and **might** only hold true on the highway.
what about city driving? do you really think the added rotational mass will save fuel during stop and go traffic??
i think your argument bashing fwd for frontal area is very weak. they can make cars more compact, that just choose not to. think of all the larger 1000+cc motorcycles. do you really think one of those motors (and transmissions) would not fit in a 1 meter wide car??? i can only think of a handful of motorcycles that are wider than 1 meter....
keep in mind this rwd vs fwd argument is for fuel efficiency not for sports cars.
don't waste your time or time will waste you
I think there are two camps of thought about FE cars , and it may be that cars will split into 2 styles for the future FE market.
One would be the streamliners , which probably is the only choice for ultimate FE and speed., and there would be the Boxfish evolution from todays cars with FE practices applied.
I dont think full sized cars as we know it will ever be great FE machines.
For an interval time they might rise in popularity (and i think auto makers will go this way) but in the ultimate end when gas is super expensive I dont think they have much future going down that path.
Untill the power hungry gass guzzlin public re-evaluates their life and driving styles and realise that what they think cars are I think the makers will go with compromised versions , which dont deliver.
Also I think that auto design should start with the engineers and not with the body stylist.
Cars need to become good machinery and not fasion statements.
?it allows for a smaller frontal area??? that is a stretch and **might** only hold true on the highway.?
Seating position , headroom and glass have the most impact on the total size and shape of the front.
So far having a large FWD engine up front hasnt been bad because it wasnt the major problem - it suits the style of body quite well.
Assuming that cars became more aero seating positions would have to be changed and then the engine bay (pointy front bit) would need to be streamlined up and this is a lot harder with the shape and format of the typical FWD power plant.
A front engined RWD engine can be placed far behind the axles centrline if required.
It can be leant over also , which makes for a very lean front end , something that designers could work with well.
As you say , maybe it would hold true on the highway , do you think people are going to be driving slower ? ...I dont , I think even when gas is expensive they still will want to go fast.
So even if the improvments are only at high speed then that is advancement., but as we have seen in this forum with the small aero mods being played with , even at lower speeds they work.
?what about city driving? do you really think the added rotational mass will save fuel during stop and go traffic???
As I said b4 , with modern materials the extras weight is minimal , especially with smaller engines that do not require tail shafts that are required to pass a lot of power.
Using modern materials I think it would only be a matter of a few killograms difference between FWD and RWD and that the possible aero advantages will make up for that and more.
?think of all the larger 1000+cc motorcycles. do you really think one of those motors (and transmissions)?
I agree 100% , but if you notice they get the less size due to an intergrated engine/gearbox and this is NOT , the conventional auto makers way.
My point was that its hard to narrow up a car (to in-line seater etc) with the current styles of powerplants.
You may not have noticed but you just agreed with what I said.
The whole idea of giving up on FWD (as we know it) would be to give auto engineers more of a clear slate to work with and design.(ide like to see the engine in the back)
If public opinion and desires dictate to the engineers it restricts what they can do.
If they are held back then how can they push realy hard forward in the rite (FE) direction.
Because of this I think Boxfish style cars will become the FE standard , but I dont think they will become anything brilliant.
Even tho the Mb boxfish concept car claims outstanding aerodynamic figures the write-ups that I have seen have said ?20 percent lower fuel consumption and up to 80 percent lower nitrogen oxide emissions?
Ime not ready to break out and dance over a 20% improvement.
Hope these links help you visualise the differnece between stremaliner and boxfish concepts.
Hi theclencher - ?the bottom half of the wheels and tires?
I was looking through a car mag today and it had a full sized family car that could go into production.
Noticable features that I saw were FLAT wheel trims and very tiny gaps around the wheel arches and flat panel work here.
There were no extended wheel arch covers.
So when the car was going straight ahead there was almost no disruption of flow along the sides.
Claimed Cd was 0.2 and and FE of 1.2l/100km which is excelent for a full sized car.
Hi theclencher - ?vehicles don't experience "head on" airflow- it's almost always a crosswind to some degree?
Yes , in the real workd its True !
Unfortunately its very unpractical to design an aero shape that is equally good from every angle that is possible for air to hit it.
As we are going forward (most of the time) at a greater speed than almost any cross wind (I havent driven in a 65mph crosswind for some time) then air flow from the front would have to be considered the most important angle.
Of course it would be nice and deeper thinking not to design in some big sail area that crosswinds could catch . -- Unless it is on the back were we can catch some of the strong easterly winds and help push us a long