MegaSack DRAW - This year's winner is user - rgwb
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A soft nosed sportsback is about what we can expect so get out of a traditional “car” shape.
Not strictly true, the kammtail design (as used in a lot of modern bike frames, helmets etc) lets you use a conventional "blunt" end of an aerofoil shape for the front of the car, then that lip at the back creates an invisible tail of eddy currents which allow the air flowing off the body to stream off as if there was a full aerofoil.
It's the reason a lot of fairly blunt rear'ed cars aren't half as bad for fuel economy as your gut tells you they should be.
The Costin Amigo, reputedly the lowest production car CdA ever (the Cd low, and the A was tiny, just look at it!).
The answer to this question can be found in the Ford Kuga.
It is basically a Fiesta made heavier, less efficient, but BIGGER. And people (dare I say it especially yummy mummies) want a BIG car. So they can feel BIG and IMPORTANT.
Same with aerodynamics - if it doesn't make you feel like a Panzer commander it must be for people who earn less money you - or hubby.
Real world figures rather than manufacturers. I’ve never really paid a lot of attention to the brochures MPG figures for exactly that reason.
Unfortunately, too many manufacturers trying to game the system for too long. If you've ever driven an US product from the days of 55mph speed limits and CAFE, you would have experienced the wonderful feeling of a car designed to go 55. The transmission, lockup torque converter, engine, everything - all designed to to return max fuel economy at exactly 55. Drive at any other speed and it's much nicer but way less efficient.
To some degree the aero of a car is limited by crash safety and the like. You could have a far more aeor car that would separate a pedestrian at the knees in the event of a collision, the top half flowing gracefully over the car, the shins left in situ. It would not ever make it into the road these days though.
I’m hoping that we’ll see legislation to force this issue because I can’t see the the average British new car purchaser (us secondhand buyers are essentially irrelevant) moving away from this obsession with 4x4 style cars.
Driving less far is excellent. Driving slower likewise (I heard my last car going much more turbulent as it approached 80 and the fuel consumption dropped rapidly). But it all matters and if you drove less far, more slowly, in a smaller, lighter and more aerodynamic car with lower rolling resistance with an efficient powertrain then it would be better.
SUVs are fundamentally worse at everything, unless they’re a true 4x4 and you’re pulling horse boxes out of fields (so higher weight and traction matters). Worse aero. Worse handling and/or worse (high CoG requires stiffer suspension). Worse rolling resistance. More particulates from brakes and tyres. Less space for people or luggage from a given footprint.
It is basically a Fiesta made heavier,
it's nothing to do with the fiesta.
it’s nothing to do with the fiesta.
Yep, it's it's big brother the Focus.
The pointlessly jacked-up Fiesta is the bizarrely named and even weirder looking EcoSport, and slightly less weird looking but same concept, Puma.
Pedantry aside he has a point. People go out of their way to buy oversized cars.
I’m hoping that we’ll see legislation to force this issue because I can’t see the the average British new car purchaser (us secondhand buyers are essentially irrelevant) moving away from this obsession with 4×4 style cars.
We have (or we had). If no-one cared we'd still all be buying 35mpg cars. There was the 'agreement' with the EU and car manufacturers to reduce average emissions across the fleet to 120g/km CO2 or was it even lower? The problem is that for market reasons the average can still allow for less efficient SUV type cars.
You could say that every passenger car has to have emissions under 100g/km - but that's going to be moot soon because we'll all be buying electric.
You could say that every passenger car has to have emissions under 100g/km – but that’s going to be moot soon because we’ll all be buying electric.
True, although you could stipulate targets in miles/kWh or equivelent.
This gives me a great idea to solve the problem of boy racers locally. Now that all the cars will be controlled by a computer, make it so that they have to conform to the manufacturer's efficiency specs. If you want to get all pop and bangy in your stretched, cambered and fart-cannoned MX5 away from the lights. You have to earn it by driving like a nun all week for your Saturday night quarter-mile, otherwise, it cuts out halfway and your underage date goes away unimpressed.
I think there are 3 main issues. 1 weight cars are getting heavier which takes more energy to accelerate and decelerate. 2 the growth of suv and the war cars are getting bigger and bigger. 3.we drive a lot further whether it’s kids too school, the commute as well as for leisure.
specifically cars can get more aero. Many cars don’t need wheels and tyres as wide as they are, but they look good and sell cars. Rear wheels could be faired in like they are on many lorry trailers. I’m sure there are plenty of other things those who know about the science could do if it would sell
Way back when in the 80s Ford brought out the Sierra – possibly one of the first cars designed with aero in mind (dustbin wheel trims included)
TBH the Sierra had a pretty poor drag coefficient (Cd was about 0.37-0.4) and Cdx too, oh and that exciting design flaw that made it, ahem, "interesting" in sidewinds. I worked on a car by Daewoo (remember them?) where the Korean engineers decided to not do any aero testing and somehow managed to design the rear screen at the exact perfect angle that they got it to generate significant rear end lift when driving at high speed in nice constant gentle turns, like you get on say, a motorway...found out 4 weeks before production start! My old design boss at Ford would tell stories of how the Audi A2 aero was dramatically improved with two drinking straws attached to the rear lamps...But I digress...
Aerodynamics is a still a bit of a black art (spent more than a few interesting, very long late night sessions in wind tunnels or reviewing/correlating CFD data playing about with various cars while have aero engineers drumming this into me) and is just part of the overall efficency of the vehicle. It needs to be done with respect to a lot of other factors, sidewind/crosswind stability is very important, making sure you don't create lift or indeed downforce as they can both muck up the cars dynamics if you get things wrong, getting cooling air into and then heat out of engines, rolling resistance (tyres have a huge impact on mpg), mechanical resistance, weight (screwed up by those pesky crash tests...) speed (very rough rule of thumb is you use 25% more energy to go at 80mph than 70mph) etc etc. Oh, and not driving with a lead right foot helps a great deal too...
An interesting thing, a 1986 BMW M3 had the same drag coefficient as a 1986 Porsche 944 Turbo.
For those too young to remember, they were very different shaped cars. The BMW looks very Square and upright compared to a 944, but they both were 0.33.
stories of how the Audi A2 aero was dramatically improved with two drinking straws attached to the rear lamps…
I always thought this was a great design feature. I assume it controls the point at which the airflow detaches at the rear of the car. Very subtle & clever to integrate it into the light cluster.
The previous gen Honda Civic had a similar thing on the rear flank of the car, but this was more of a lip stuck-on to the existing bodywork rather than an intergrated design.
SUVs are fundamentally worse at everything,
Err, no they're not. I was never a fan of SUV's and still not my first choice of a car, but as the wife got one and I've actually experienced using one they are actually very good cars. Very comfortable especially when all the family is out, pretty practical, modern ones have decent interior space, drive perfectly fine with very good body control so none of that wobbling effect you got with the early SUV's, extremely economical - only a few mpg worse than the equivalent saloon version of the same car. No real downsides unless you want driving dynamics and something with a sporty feel. But then having been in my mates big X4M that has that in spades too - 4 second 0-60 so more than enough umph and goes round bends as composed and balanced as any car and still returns over 50mpg on motorway runs.
Also with so much grip on offer will tear the tarmac off the road before letting go. Only quick direction changes seem to befuddle it. Can do it, but obviously not as composed as a smaller lower car. As for the worse aero did you not see my previous comments comparing an X3 to 5 series...pretty much to all intents and purposes similar aero characteristics in terms of C of D and frontal area...marginally better with the 5 series but not a big gap at all.
Cars are being driven to be larger and heavier not because people necessarily want bigger cars (look at the popularity of modern small cars like mini's and Fiat 500's), but it's the crash regulations that are driving cars that way. They are more reinforced so heavier and larger becasse you want to increase the distance between people and points of impact. Couple that with the relatively recent introduction of 'pedestrian friendly' cars that cause less damage to people if they are run over presents further challenges to designers who are trying to improve efficiency as well as comply with all the safety regulations that are working against efficiency. the result is ever growing cars in size and weight.
stories of how the Audi A2 aero was dramatically improved with two drinking straws attached to the rear lamps
Yes, I remember some Nascar engineers getting suspended for illegal use of race tape to subtly improve the aero. Nascar aero is probably much more relevant to road cars than F1 because they are based on road cars, need low-drag for speed, but also need to be stable when they are close to other cars or if they spin. At the speeds they go, getting airbourne is a serious danger when they spin.
The thing about SUVs is they exist as a response to legislation on pedestrian impact protection NOT because the average buyer desperately wants one. It’s much easier to make an appealing looking car that’s safe for pedestrians with a tall front end.
My calibra in the 90’s was slippery as a fish but hit a child with one and the leading edge of the cylinder head being multimeters below the bonnet and it’s not going to end well.
did you not see my previous comments comparing an X3 to 5 series…pretty much to all intents and purposes similar aero characteristics in terms of C of D and frontal area…marginally better with the 5 series but not a big gap at all.
Did you not see where I disputed that? If the X3 is only 'a few mpg worse' than a 520 you'd better let BMW know.
"It’s much easier to make an appealing looking car that’s safe for pedestrians with a tall front end."
I'd love to see the data on - on average - SUV's being more pedestrian safe than a car. Please?
Aero cars come out better in test on the least pedestrian unfriendly cars:
https://www.carscoops.com/2016/04/top-5-pedestrian-friendly-cars-tested/
SUVs and trucks are 50% more likely to kill pedestrians and cyclists:
https://www.outsideonline.com/2411345/suvs-trucks-deadly-cyclist-crashes
The real horrors you'll find in here:
The Jeep, vans and SUVs are the most predestrian unfriendly.
wobbliscott
goes round bends as composed and balanced as any car
wobbliscott
Only quick direction changes seem to befuddle it. Can do it, but obviously not as composed as a smaller lower car.
🤷♂️
“It’s much easier to make an appealing looking car that’s safe for pedestrians with a tall front end.”
I also doubt this - the first car to meet the new pedestrian safety regs was the Peugot 4-something I think, the saloon car.
The thing about SUVs is they exist as a response to legislation on pedestrian impact protection NOT because the average buyer desperately wants one. It’s much easier to make an appealing looking car that’s safe for pedestrians with a tall front end.
Nope?
If that were the case then why would manufacturers build them on the exact same platforms as the "normal" cars.
SUV’s, extremely economical – only a few mpg worse than the equivalent saloon version of the same car.
Except that is the problem.
Everyone thinks "its only 5mpg/10% worse than the estate, I can live with that in return for the status infered by my Vauxhall mk4 challenger tank". Then the net result is everyone's emissions are higher than they need to be.
It's like when people go to a restaurant, knowing that the bill will be split and therefore order the steak and the red wine. Then wonders how the bill got to £50 a person in the pub where you normaly have the beer and a burger for under a tenner.
It's just assuming that everyone else will be more frugal to make up for your choices.
I agree with a lot of the anti SUV sentiment here.
This quote from a 2019 wired article always struck me as shocking:
“ Over the last eight years, electric cars were responsible for a 100,000 barrel per day reduction in demand for oil, while increases in fuel efficiency in smaller cars saved another two million barrels a day. But the rise of SUVs, meanwhile, accounted for an increase of 3.3 million barrels a day in oil demand.”
It also mentions that SUVs are twice as likely to kill pedestrians due to them being knocked down rather onto the bonnet.
Source: https://www.wired.co.uk/article/suv-cars-hybrid-electric-impact
Dont get mixed up between SUV's and Trucks (aka Pick-up's) as theye are actually very different things:
SUV's in Europe still have to comply with full NCAP crash test requirements including pedestrian impact tests. Trucks, on the other hand, are not classified as cars (or even IIRC, LCV's for that matter) and therefore dont...
Not sure Mr Musk understands aerodynamics, given his version of a truck could be easily confused with an industrial fridge freezer.That said, assembly costs must be cheap, all those flat panels.
Aero cars come out better in test on the least pedestrian unfriendly cars:
Or not. If you actually look at the article aero has very little to do with it. The Cx3 is less aero than the scirroco for instance.
Not sure Mr Musk understands aerodynamics, given his version of a truck could be easily confused with an industrial fridge freezer.
Is it comparable with a regular truck or less coefficient?
* I mean is it less aerodynamic than average/regular trucks?
As pointed out, modern cars have to be bigger to accommodate all the mandatory crash protection, like airbags along the sides and for the passenger, instead of one for the driver in the steering wheel, greater crash protection in the doors, crumple zones, etc.
Look at the construction of an original Mini, compared to a base model BMW Mini
True to a point, but the 'new' mini is style over everything and a proper bloater, its not in the same category. A better comparison would be old mini vs the Pug 108, Citroen C1 and Toyota Aygo which are less than 50cm longer and in the same bracket of accessible, economical motoring, with basic safety features.
* I mean is it less aerodynamic than average/regular trucks?
Apparently not.
flannol
Free Member
“It’s much easier to make an appealing looking car that’s safe for pedestrians with a tall front end.”I’d love to see the data on – on average – SUV’s being more pedestrian safe than a car. Please?
Posted 11 hours ago
The explanation I read which I can't now find was the was 2 risk factors with 90's aero cars like my calibra was that a Childs head hits the cylinder head which is unavoidable in a low fronted fed car. For adults, the head hits the wipers or windscreen whereas a range rover would gently fold you onto the bonnet 😎
Thats not to say you can't make a saloon anymore, but engines are the shape they are so now need a taller front end to protect kiddiewink which makes for difficult styling for a saloon or coupe but is easy to accommodate on an SUV style car
The explanation I read which I can’t now find was the was 2 risk factors with 90’s aero cars like my calibra was that a Childs head hits the cylinder head which is unavoidable in a low fronted fed car
This isn't true, there are plenty of saloon cars with space under the bonnet that gets them the 5 star ratings. There was an article on TV I watched about it at the time, and they showed the bonnet deformation. That's why the car looked weird at the time.
Is that not why Nissan GTR's have those explosive struts for front impacts?
I mean is it less aerodynamic than average/regular trucks?
I reckon a fridge is less aerodynamic than a modern SUV.
Can I mention weight and what I might wrongly call primary safety now we are into SUV and truck bashing...
Weight - SUVs are heavier which means in addition to the aero point they also take more energy to drag up hills and to accelerate up to a speed. They also need to convert more energy during deceleration.
If we are on SUV safety the most important safety features of any car are arguably those that contribute to NOT having an accident in the first place.
That means handling, braking, mechanical grip, sight lines/blind spots for the driver, an internal environment that is not distracting/encourages attention to the road and doesn't engender a feeling of I'm alright safe up here in my status megabox looking down on the world.
SUVs fail miserably compared to an equivalent estate on a number of those and their emissions (particle and engine) and aero are a heap worse.
Don't know what the NCAP ratings are but being struck by a bus fronted Range Rover isn't going to end well for anyone small regardless of how much room there is between bonnet top and cylinder head.
@dudeofdoom thnks for the link
From the AirShaper article:
Drag Coefficiency
Our initial simulations calculated a drag coefficient of 0.48, which is more than double the drag of the Tesla Model 3 (Cd of 0.23). This is particularly impressive for an electric pickup truck. The results from our initial analysis highlight that the aerodynamic features of the Tesla Cybertruck are not only interesting, but impressive. We are looking forward to conducting some further analysis once we receive a more detailed model.
Also found this:
... the drag coefficient of the Cybertruck can even be 0.3Cd which is really impressive for a pickup truck. For reference, Tesla’s most aerodynamic production car is the Tesla Model 3 with a Cd of 0.23 — Next-gen Tesla Roadster is expected to break all aerodynamics records for a production sports car
I’m not saying Tesla is the best in the world for aerodynamics, but curious @dyna-ti for singling out Musk/Tesla as somehow exemplary of ignorance.
😆 oh no, have I annoyed a Musk fanboy ? Dont make comparisons with a fugly truck and a fridge.
Re safety I have had this argument before - some years ago I found a page of stats in the US showing occupant deaths per mile grouped by car model. There were SUVs and normal cars scattered through the list, with slightly more passenger cars higher up the list IIRC (with the top of the list being lowest deaths of course).
Not at all, I’m more of the bicycle sort. Also never brand-loyal. That’s some teenage thingisn’t it? Like Playstation vs Xbox? No
From your (non)-answer, I’ll assume that projection is at play? But no, you mistook curiosity/question to be anything other than literal. I was under the (maybe wrong) impression that Tesla had developed notably aerodynamic production cars/trucks by market comparison. Yet I also wondered why someone would have the exact opposite impression. Call it my thirst to cross-reference and factcheck. It’s good (IMO) to challenge one’s beliefs/impressions.
I too believe trucks (especially the Tesla one) to be enormously ugly (aesthetically), but aesthetics =/= aerodynamics
It may be quite aero for a truck, but it's not aero for a personal vehicle, and let's not kid ourselves that it's going to be used for any kind of utility purpose.
So it's still a bad vehicle.
Correction: I meant to quote dyna-ti’s ‘Musk fanboy’ jab (attempt), yet mistakenly seem to have posted a bike image. Apologies.
So it’s still a bad vehicle.
That wasn’t the metric I was contending, but yeah. Trucks are bad mkeh. And can we all agree that ‘utility’ doesn't mean carting MTBs around? 😉
What I take from this is Elon Musk thinks MTBs should have kickstands. Which makes him evil.
Sorry P7eaven, that was more a counter jab 😉 Seemingly as you ignored the entire thread containing beautiful curves surfaces to have a go at mine on flat surfaces, even to the point of providing data, charts and wind tunnel data/pictures to prove a point.
That point being that Elon Musks fugly pick up truck was the breakthrough several decades of vehicle, boat and plane manufacture and design had missed. All their own charts, pictures and wind tunnel data must have been fundamentally flawed, and all the time they should have used flat surfaces not curved ones.
It's a bit like NASA, stoically sticking to a phallic shaped space rocket, when everybody knows that interplanetary craft used by aliens is saucer shaped 😉
Tesla (and other EVs) have a big aero advantage in that they don't need the big radiators or airflow of an ICE. There's a big limit on how aero the front of a car can be when it needs to let the air in,, and then through the engine bay and out the bottom. (which also of course impacts how aerodynamic the underside can be, as does the exhaust). And a radiator is basically a big drag device.
But those pics of hte tesla truck vs pickups are terrible comparisons, since the tesla shown is in closed back configuration while the pickups are open bed.
Seemingly as you ignored the entire thread containing beautiful curves surfaces to have a go at mine on flat surfaces, even to the point of providing data, charts and wind tunnel data/pictures to prove a point.
That point being that Elon Musks fugly pick up truck was the breakthrough several decades of vehicle, boat and plane manufacture and design had missed. All their own charts, pictures and wind tunnel data must have been fundamentally flawed, and all the time they should have used flat surfaces not curved ones.
Elaborate strawman, but again, no.
As in no, that was not my ‘point’. Neither was I ‘jabbing’ anyone. Sorry if that’s what you took from it, though in my defence I did make a strong attempt to be clear.
It (my question/curiosity) was as simple as:
is it less aerodynamic than average/regular trucks?
So yeah. I’m oot on this one. Lesson learned! Furthermore, I don’t like Elon Musk and I too think his flat panel truck is fugly and I’m sorry I asked the question, OK!? 😅 😅
But those pics of hte tesla truck vs pickups are terrible comparisons, since the tesla shown is in closed back configuration while the pickups are open bed.
Good point.
all the time they should have used flat surfaces not curved ones.
Exactly
F117... Known for the absolute necessity to have a working computer for being able to stay in the air. Designed with radar cross-section as the primary concern and the aerodynamics of an angry brick. The fact that most/all modern fighter jets have similar looks is nothing to do with aerodynamic efficiency and everything to do with reducing 90 degree angles and _not_ reflecting radar returns.
That diagram of the modelled airflow of the cybertruck makes me think that the main benefit it has is the lack of abrupt transition from cab to load bed and the drag that will produce. If you walled in the F150's bed in the same way, I'd be interested to see how that looks with the same model.
They really need to get people who know a bit about MTBs before putting MTBs in a marketing shot.
^
It was more a marketing shot for (flame-throwing) Ti e-MTBs.
The RLE Apocalypse electric bikes will help you out in situations where even the TESLA Cybertruck is powerless! These titanium electric bikes are equipped with racks for various attachments and even have mounts for a Boring Company flamethrower.”
(As if the truck and it’s unveiling alone didn't seem douchebaggy/‘apocalypse-chic’ enough!, IMO)
F117 is not aerodynamic at all as Willard has pointed out. Any product is designed against q set of criteria..a specification and for military aircraft efficiency is way down the list. Compare the design of the F117 where stealth was the dominating design requirement to an Airbus A350 or Boeing 787 which were designed with fuel efficiency as the dominant feature. Those two aircraft look very different. Sharp facetted shapes like the F117 and cybertruck are generally not very aerodynamic at all. The sharp edges generate turbulence and drag.
A normal pick up truck is not exactly a very aerodynamic thing to begin with so comparing the cyber truck to those is not really saying much at all. You can significantly increase the aerodynamics of a normal pick up truck just by opening the tail gate when driving or putting some form of topper on it, which is really what the cybertruck has. Would probably be more aerodynamic than the cyber truck if you were to do any of those two things.
You can significantly increase the aerodynamics of a normal pick up truck just by opening the tail gate when driving or putting some form of topper on it, which is really what the cybertruck has. Would probably be more aerodynamic than the cyber truck if you were to do any of those two things.
That’s the answer I was looking for 👍🏼
Musk/Tesla must have either dropped the ball really hard to make a ‘future’ truck that’s actually less aerodynamic than standard pickups. Or else they decided to design it simply as a headline-grabber, meaning that it will probably languish/be still-born as a concept. Thankfully 😉
It begs the question, are their other efforts similarly (aerodynamically) sub-par by market comparison?
You can significantly increase the aerodynamics of a normal pick up truck just by opening the tail gate when driving
People in the US do this to make their truck 'go faster' but it's actually banned in many areas because they are constantly leaving things in there which then fall out and cause problems.
Those bikes were the subject of the shot? Bloody hell they look like supermarket specials.
So yeah. I’m oot on this one. Lesson learned! Furthermore
Sorry no, this is my fault. I blame the lack of emjoi things, I felt i was being put on the spot being asked to explain the ins and outs of fluid dynamics over making a joke about fridges and ugly designs. Wasnt wanting to get into a subject I clearly know nothing about, other than to speculate flat surfaces would seemingly be less aerodynamic than curved, and every post seemed to me to be a counter post. I put my hands up to being a bit thin skinned currently, react with a bit of indignation. I apologize wholeheartedly. Sorry buddy 🙂 my fault.
Been stuck in so long, just a bit(a bit 😕 ) edgy and lack of emotion in threads can to me currently come across as too serious. I see that now. Sorry if I've offended you 🙂 you've nothing to be blamed for. All me.
I'll keep my one sided jokes to myself.
@Thols2
I think the wings are dynamically curved, just the flat surfaces are as also suggested more to do with radar reflection and appearing stealth than something designed to be fuel efficient. 🙂 American public are picking up the fuel bill, and the airforce/reds under the bed fearing public care nothing about it or how many times it needs to go aloft
@dyna-ti, no worries thnks! 😅 I am a bit ‘spectral’ (see hyper-literal) at times, it (unintentionally) catches people out 😅
No agenda. All good.