why are cheaper cars FWD?

[E21_Ross]

In general, cheaper cars are FWD, e.g. small family cars, but more expensive cars are either RWD or 4WD. is FWD cheaper to make?

random question i know

Edited by E21_Ross on Monday 29th March 14:43

[soad]

E21_Ross said:

In general, cheaper cars are FWD, e.g. small family cars, but more expensive cars are either RWD or 4WD. is FWD cheaper to make?

random question i know

EFA

[ewenm]

I think it's in general smaller cars are FWD due to the packaging benefits (no driveshaft stealing interior space) and larger cars inherently have more space so have more drivetrain options. Smaller cars tend to be cheaper.

[E21_Ross]

soad said:

E21_Ross said:

In general, cheaper cars are FWD, e.g. small family cars, but more expensive cars are either RWD or 4WD. is FWD cheaper to make?

random question i know

EFA

just edited it myself you knew i knew what i meant from the thread title

[5lab]

its also down to power

150-200bhp is easy to a front driver - but there's not many cars >50g with less than 200bhp - as a result, sending some\all power to the back is the sensible solution

[The Wookie]

ewenm said:

I think it's in general smaller cars are FWD due to the packaging benefits (no driveshaft stealing interior space) and larger cars inherently have more space so have more drivetrain options. Smaller cars tend to be cheaper.

IIRC also cheaper to build as the whole lot is tested and lifted into the car in one go as a whole with the subframe. As opposed to two bits with a need to connect them up with a driveshaft, which needs to be designed, aligned properly, costs money, etc etc.

[Twincam16]

It's easier to platform-engineer a whole FWD range - all you need is a selection of generic FWD engines/gearbox/halfshaft combinations attached to a chassis the length of which can easily be shortened or lengthened. The result may not be the best-handling thing you've ever seen, but it's a way of engineering a large range of cars for minimal outlay.

RWD, because of the propshaft and corresponding torque stresses on the bodywork, means pretty much each model needs developing individually.

That said, just because a car is FWD doesn't mean it's engineered on a shoestring. The Alfa Romeo F/4WD platform underpinning the 159, Spider and Brera cost a fortune to develop and produces superb handling, as does, I understand, the new generation of Saabs. Next month I'll be test-driving the new Citroen C6, which I understand also has a fairly bespoke platform and a corresponding price tag.

[Jayho]

Well back in the day majority of cars were actually RWD... But think that they found it cheaper and more economically viable to produce cars with FWD with the reasons mentioned above.

Popularity of supermini's and easy platform also makes it easier to have a similar platform across.

Nowadays its also to do with the norm, most people learn in FWD cars and probably are used to driving FWD cars therefore going to a RWD becomes a little more difficult to control in bad weathers.

[Mr2Mike]

Packaging. The entire powertrain is small and lighter and doesn't intrude on passenger space as much.

Cost. A transaxle is much cheaper than a separate gearbox, propshaft and rear axle. Very simple/compact rear suspension systems can be used, cheaper, lighter and smaller.

Edited by Mr2Mike on Monday 29th March 16:03

[RobM77]

FWD benefits include:

• Cheaper to make (as the OP rightly guesses). The oily bits are all together as one unit at the front of the car.

• More interior space. No rear diff and driveshaft.

• More compact. avoiding a long driveshaft and engineering all the oily bits together achieves compactness, as does a transverse engine layout if the car has an inline engine. The original Mini showed this very well.

• Easier control of Noise Vibration and Harshness. Isolating a mechanical unit at one end of the car is easier and cheaper than isolating mechanical components all around the car.

FWD disadvantages are:

• Front wheels do everything: the steering and the driving, so the driving experience is very "one ended", so you feel like you're being dragged everywhere. Cars tend to be (or should I say "can be") more enjoyable when both ends of the car do something.

• Weight transfer under acceleration gives the rear wheels more grip and the front's less. In a FWD car the engine's task of delivering power is therefore counter productive, because the more power it delivers, the less the power can be used. In a RWD car the opposite is true - the more power you give, the better the grip generated to deploy it (up to the limits of the tyre).

So the more a car is expected to appeal to a driver, the better the case for it not being FWD, thus the price connection the OP hinted at. With very few exceptions, FWD performance cars are only FWD because they're based on basic shopping cars - a ground up design for a performance car is almost always RWD (the Elan M100 is the only example I can think of that breaks this rule). That's not saying that FWD performance cars can't drive well (look at the Integra Type R for instance, or the Clio 172/182/197), but enjoyable FWD cars are making the best of a limited situation - RWD allows far more scope for enjoyment. A good analogy might be alcohol at a party - it doesn't make a party good to have good booze, and it doesn't make a party bad to not have it, but it really helps!

Edited by RobM77 on Monday 29th March 16:12

[Twincam16]

Jayho said:

Well back in the day majority of cars were actually RWD... But think that they found it cheaper and more economically viable to produce cars with FWD with the reasons mentioned above.

That's because the packaging of FWD drivetrains was something of an art back in the '60s and '70s and cost a lot to develop. Also, there were more cars with separate-chassis construction back then, so it was possible to engineer just one chassis, engine and drivetrain, usually FE/RWD, and design a whole load of bodies to bolt on top of it.

[annodomini2]

RobM77 said:

FWD benefits include:

• Cheaper to make (as the OP rightly guesses). The oily bits are all together as one unit at the front of the car.

• More interior space. No rear diff and driveshaft.

• More compact. avoiding a long driveshaft and engineering all the oily bits together achieves compactness, as does a transverse engine layout if the car has an inline engine. The original Mini showed this very well.

• Easier control of Noise Vibration and Harshness. Isolating a mechanical unit at one end of the car is easier and cheaper than isolating mechanical components all around the car.

FWD disadvantages are:

• Front wheels do everything: the steering and the driving, so the driving experience is very "one ended", so you feel like you're being dragged everywhere. Cars tend to be (or should I say "can be") more enjoyable when both ends of the car do something.

• Weight transfer under acceleration gives the rear wheels more grip and the front's less. In a FWD car the engine's task of delivering power is therefore counter productive, because the more power it delivers, the less the power can be used. In a RWD car the opposite is true - the more power you give, the better the grip generated to deploy it (up to the limits of the tyre).

So the more a car is expected to appeal to a driver, the better the case for it not being FWD, thus the price connection the OP hinted at. With very few exceptions, FWD performance cars are only FWD because they're based on basic shopping cars - a ground up design for a performance car is almost always RWD (the Elan M100 is the only example I can think of that breaks this rule). That's not saying that FWD performance cars can't drive well (look at the Integra Type R for instance, or the Clio 172/182/197), but enjoyable FWD cars are making the best of a limited situation - RWD allows far more scope for enjoyment. A good analogy might be alcohol at a party - it doesn't make a party good to have good booze, and it doesn't make a party bad to not have it, but it really helps!

Edited by RobM77 on Monday 29th March 16:12

FWD is also easier for numpties to drive and is statistically less likely to put you in a dangerous position when you lose control.

[RobM77]

annodomini2 said:

RobM77 said:

FWD benefits include:

• Cheaper to make (as the OP rightly guesses). The oily bits are all together as one unit at the front of the car.

• More interior space. No rear diff and driveshaft.

• More compact. avoiding a long driveshaft and engineering all the oily bits together achieves compactness, as does a transverse engine layout if the car has an inline engine. The original Mini showed this very well.

• Easier control of Noise Vibration and Harshness. Isolating a mechanical unit at one end of the car is easier and cheaper than isolating mechanical components all around the car.

FWD disadvantages are:

• Front wheels do everything: the steering and the driving, so the driving experience is very "one ended", so you feel like you're being dragged everywhere. Cars tend to be (or should I say "can be") more enjoyable when both ends of the car do something.

• Weight transfer under acceleration gives the rear wheels more grip and the front's less. In a FWD car the engine's task of delivering power is therefore counter productive, because the more power it delivers, the less the power can be used. In a RWD car the opposite is true - the more power you give, the better the grip generated to deploy it (up to the limits of the tyre).

So the more a car is expected to appeal to a driver, the better the case for it not being FWD, thus the price connection the OP hinted at. With very few exceptions, FWD performance cars are only FWD because they're based on basic shopping cars - a ground up design for a performance car is almost always RWD (the Elan M100 is the only example I can think of that breaks this rule). That's not saying that FWD performance cars can't drive well (look at the Integra Type R for instance, or the Clio 172/182/197), but enjoyable FWD cars are making the best of a limited situation - RWD allows far more scope for enjoyment. A good analogy might be alcohol at a party - it doesn't make a party good to have good booze, and it doesn't make a party bad to not have it, but it really helps!

Edited by RobM77 on Monday 29th March 16:12

FWD is also easier for numpties to drive and is statistically less likely to put you in a dangerous position when you lose control.

I deliberately missed that one off Like most people here, being a car enthusiast, I'm not a numpty about cars and generally don't feel any more unsafe driving RWD than FWD or 4WD. Sadly I'll never experience being a numpty because when I drove my first RWD car I'd already been driving seven years, racing one year and karting for five years, so it felt totally natural to me. Also, I don't have any experience of numpties on the limit with RWD, so I feel I can't really comment on it.

edited to say: I have passengered with some lunatics in my time, as I'm sure we all have. What scared me though wasn't the FWD or the RWD it was the lack of understanding of stopping distances and sight lines. On the occasions where I've been in cars with inexperienced drivers during loss of control moments they've all been caused by weight transfer (braking or coming off the throttle at the wrong point) and inappropriate steering technique (i.e. tank slappers). The drivetrain hasn't contributed to any of those at all.

Edited by RobM77 on Monday 29th March 16:53

[Jayho]

annodomini2 said:

RobM77 said:

FWD benefits include:

• Cheaper to make (as the OP rightly guesses). The oily bits are all together as one unit at the front of the car.

• More interior space. No rear diff and driveshaft.

• More compact. avoiding a long driveshaft and engineering all the oily bits together achieves compactness, as does a transverse engine layout if the car has an inline engine. The original Mini showed this very well.

• Easier control of Noise Vibration and Harshness. Isolating a mechanical unit at one end of the car is easier and cheaper than isolating mechanical components all around the car.

FWD disadvantages are:

• Front wheels do everything: the steering and the driving, so the driving experience is very "one ended", so you feel like you're being dragged everywhere. Cars tend to be (or should I say "can be") more enjoyable when both ends of the car do something.

• Weight transfer under acceleration gives the rear wheels more grip and the front's less. In a FWD car the engine's task of delivering power is therefore counter productive, because the more power it delivers, the less the power can be used. In a RWD car the opposite is true - the more power you give, the better the grip generated to deploy it (up to the limits of the tyre).

So the more a car is expected to appeal to a driver, the better the case for it not being FWD, thus the price connection the OP hinted at. With very few exceptions, FWD performance cars are only FWD because they're based on basic shopping cars - a ground up design for a performance car is almost always RWD (the Elan M100 is the only example I can think of that breaks this rule). That's not saying that FWD performance cars can't drive well (look at the Integra Type R for instance, or the Clio 172/182/197), but enjoyable FWD cars are making the best of a limited situation - RWD allows far more scope for enjoyment. A good analogy might be alcohol at a party - it doesn't make a party good to have good booze, and it doesn't make a party bad to not have it, but it really helps!

Edited by RobM77 on Monday 29th March 16:12

FWD is also easier for numpties to drive and is statistically less likely to put you in a dangerous position when you lose control.

To be fair i'd rather go backwards into a tree than face first!

Car which understeers goes face first into tree
car which oversteers goes ass first into tree
perfectly balanced car go sideways into tree

[RobM77]

Jayho said:

annodomini2 said:

RobM77 said:

FWD benefits include:

• Cheaper to make (as the OP rightly guesses). The oily bits are all together as one unit at the front of the car.

• More interior space. No rear diff and driveshaft.

• More compact. avoiding a long driveshaft and engineering all the oily bits together achieves compactness, as does a transverse engine layout if the car has an inline engine. The original Mini showed this very well.

• Easier control of Noise Vibration and Harshness. Isolating a mechanical unit at one end of the car is easier and cheaper than isolating mechanical components all around the car.

FWD disadvantages are:

• Front wheels do everything: the steering and the driving, so the driving experience is very "one ended", so you feel like you're being dragged everywhere. Cars tend to be (or should I say "can be") more enjoyable when both ends of the car do something.

• Weight transfer under acceleration gives the rear wheels more grip and the front's less. In a FWD car the engine's task of delivering power is therefore counter productive, because the more power it delivers, the less the power can be used. In a RWD car the opposite is true - the more power you give, the better the grip generated to deploy it (up to the limits of the tyre).

So the more a car is expected to appeal to a driver, the better the case for it not being FWD, thus the price connection the OP hinted at. With very few exceptions, FWD performance cars are only FWD because they're based on basic shopping cars - a ground up design for a performance car is almost always RWD (the Elan M100 is the only example I can think of that breaks this rule). That's not saying that FWD performance cars can't drive well (look at the Integra Type R for instance, or the Clio 172/182/197), but enjoyable FWD cars are making the best of a limited situation - RWD allows far more scope for enjoyment. A good analogy might be alcohol at a party - it doesn't make a party good to have good booze, and it doesn't make a party bad to not have it, but it really helps!

Edited by RobM77 on Monday 29th March 16:12

FWD is also easier for numpties to drive and is statistically less likely to put you in a dangerous position when you lose control.

To be fair i'd rather go backwards into a tree than face first!

Car which understeers goes face first into tree
car which oversteers goes ass first into tree
perfectly balanced car go sideways into tree

To be honest that's more to do with the chassis tuning than the drivetrain.

Yes, a rear wheel drive car will oversteer if:

a) poorly driven,
b) it's wet
c) the speed is low enough
d) there's enough power

So that's four conditions that all need to be present to make a RWD car oversteer - it's too tenuous for me! Chassis tuning is the biggest factor.

[Robert060379]

Because front wheel drive is for people who can drive; where as rear wheel drive is for drivers.

[fluffnik]

A FWD drivetrain has fewer parts - no propshaft, final drive in unit with gearbox - and is easier to install as a pre-built sub-assembly since it all happens at one end of the car.

[Beirut Taxi]

Interestingly the transmission in a rear wheel drive (transverse layout) car is actually more efficient than a longitudinal layout in a FWD car. I am yet to understand why though.

Edited by Beirut Taxi on Tuesday 30th March 21:14

[RobM77]

Beirut Taxi said:

Interestingly the transmission in a rear wheel drive (transverse layout) car is actually more efficient than a longitudinal layout in a FWD car. I am yet to understand why though.

Edited by Beirut Taxi on Tuesday 30th March 21:14

That's interesting. I'd be interested to see a technical response to that if anyone knows why?

[Caruso]

Beirut Taxi said:

Interestingly the transmission in a rear wheel drive (transverse layout) car is actually more efficient than a longitudinal layout in a FWD car. I am yet to understand why though.

Edited by Beirut Taxi on Tuesday 30th March 21:14

Surely that should be the other way round?

FWD tend to be transverse, whereas RWD tend to be longitudinal unless mid engined.

Edited by Caruso on Wednesday 31st March 00:10