Safe Speed Forums

So what do people prefer?

Front wheel drive (understeer galore but easier to recover from than oversteer)?

Rear wheel drive (tends to oversteer but if you know what you're doing you can control oversteer in a powerslide, flick of opposite lock and back it comes)?

Four wheel drive (sticks like glue but gives you very little warning between "you're almost at the limit" and crossing the limit and sending you into a 4-wheel drift)?

I've driven all 3, passed my test in a FWD car, owned a Fiesta (FWD), an A3 (FWD) and an A4 (FWD), driven a few Mercs (RWD) and a 3-series BMW (RWD), current car is an A4 Quattro, as was the previous one.

My personal view is that RWD is much better than FWD but 4WD beats RWD in anything other than a straight line.

Just wondered what other people's opinions were? When I talk about 4WD here I mean things like Audi's Quattro system, the 4WD version of the Jag X-type, the Impreza etc, not "off-road but most won't actually work off-road" vehicles like the X5, Range Rover and other "Chelsea Tractors". Basically a normal saloon/estate/hatchback which happens to have a 4WD system.

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Magistrates rule #1: "Never let justice get in the way of a conviction."

Not 4WD.

not in a finacial position to choose anything other than front wheel drive. It's paid for, it always works so that'l do untill my premium bond ship comes in or my long lost wealthy relative snuffs it. I value unfaltering reliablity before which wheels are driven.

4wd or rwd. Lucky to have both. Wouldn't touch FWD now as I find it disconcerting as the rear of the car never quite feels attached to the road and feel far more out of control with fwd than either rwd or 4wd. FWD is ok with the heavy footed clots. RWD isn't which is why a lot of people get unstuck as you can't just hoof it like a muppet.

Wouldn't touch a 4wd with a high centre of gravity though - definitely better to go for the ex rally cars like the integrale or impreza.

FWD is cheap and easy to manufacture, and like said more docile to drive.

Only thing I find perplexing is why so many so-called performance cars use it. I can understand the above criteria being "okay" for shopping trolleys, cheap hatchbacks and the like, but "drivers" cars like coupes?

Evan many 1 ton (3 ton~ GVW) vans are FWD now, which is a joke.

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Fear is a weapon of mass distraction

for driving on the public road .... whatever's cheapest.

FWD vans have a more compact drive train that doesn't interfere with the load area. With a bit of clever suspension design you can have you wheels hanging from the rear wheel arches and the floor nice and low to the ground. Easy for loading and unloading. FWD mans there are no transmission tunnels to fill up the cab, so you should have a nice flat cab too.

I know the reasons, and I suppose in a simple city-bound delivery wagen it may make sense, but a lot of the time it's a poor compromise. My RWD vito has a comparable load floor to FWD competitors, simply through good engineering. FWD is the lazy option.

The higher-powered VW's have rep for eating driveshafts... 300+ ft/lb of torque vs. 3 ton through the inherently more flimsy FWD driveshafts was a bad idea.

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Fear is a weapon of mass distraction

It's to do with the separation of concerns. It lowers the coupling between components of the car. Any design decision can make the car faster, cheaper or more reliable, but rarely all three at once. Where cost is a concern (i.e. always), the cheapest/most reliable design will often win out over performance.

Low cost options are preferable to high cost options, unless you need more performance or quality. Very few cars have too low performance or quality, and that is why we get FWD cars.

It's the three (or more) way trade-off. You can have two (low cost, high quality or high performance), but not all three.

I think I like RWD, but always end up buying FWD. I need something small and practical which pretty much precludes RWD these days.

They also work better in the snow, which anyone who has had to take out an RWD van in the snow without the aid of a Bosch washing machine will know.

If you are not an enthusiast, and the weather outside is not 'frightful', AWD is a waste of weight and centripetal momentum, both of which are a detriment to fuel economy. Also, AWD never helps braking.
If you live where inclement weather is the norm, or other situations where grip is regularly at a compromise, it can never exceed the tire selection.

If you are not an enthusiast, RWD is more than adequate if good grip is usually available, and the primary concern is the ability to carry or pull extra weight, since the weight transfer upon acceleration complements where the workload already should be.
Otherwise, the lighter in the rear it is, the worse RWD is, especially in inclement weather. (This tendency is somewhat mitigated by mating the transmission with the axle at the rear, but this only tends to happen in cars whose primary mission is pleasing the driver; I doubt they'll ever make any sort of work vehicle like this.)

If you are not an enthusiast, FWD offers the best packaging in terms of both space and weight efficiency, the latter being of prime importance to good fuel economy. It also offers the simplest handling paradigm (the throttle is NOT for steering).

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The Rules for ALL ROAD USERS:
1) No one gets hurt
2) Nothing gets hit, except to protect others; see Rule#1
3) The Laws of Physics are invincible and immutable - so-called 'laws' of men are not
4) You are always immediately and ultimately responsible for your safety first, then proximately responsible for everyone's
Do not let other road users' mistakes become yours, nor yours become others
5) The rest, including laws of the land, is thoughtful observation, prescience, etiquette, decorum, and cooperation

If you are an enthusiast, AWD definitely handles excesses of power and shortages of traction better than RWD. That said, all the best AWD systems usually mimic RWD until it determines that the rear end could use some sort of help from the front.

Since FWD is also the cheapest and easiest thing for automakers to assemble and package, and most drivers are nonenthusiasts, many enthusiasts are dependent on the tuning of the suspension and the care that went into the quality of the mechanical design of the car.

It is worth noting that the socalled inherent understeer of FWD layouts can be counterbalanced by adding roll resistance, or barring that, stiffer spring rates to the rear of the car.
Stiffer spring rates will ruin the ride quality even faster than changing the geometry of the rear suspension, but either way, most suspensions were not designed to accomodate such changes.

_________________
The Rules for ALL ROAD USERS:
1) No one gets hurt
2) Nothing gets hit, except to protect others; see Rule#1
3) The Laws of Physics are invincible and immutable - so-called 'laws' of men are not
4) You are always immediately and ultimately responsible for your safety first, then proximately responsible for everyone's
Do not let other road users' mistakes become yours, nor yours become others
5) The rest, including laws of the land, is thoughtful observation, prescience, etiquette, decorum, and cooperation

Appart from 1 rear engine rear drive car (skoda estelle) all my cars have been front wheel drive. Car mags will say that car X understeers in the dry if pushed. Exactly how hard have you to push even a modest hatchback to induce understeer in the dry? Faster than is safe, comfortable and certainly faster than allows you to go unnoticed. Sure my front wheel drive shopping trolley understeers in the wet, but hands up who could hold a 3 Series in oversteer on a public road without incuring loss of NCB or being awarded points? Not me that's for sure.

Yes Adam, a powerful 3 series can be a bit embarrassing in the wet. I used to have a 328i Sport with LSD and this would go sideways at the drop of a hat. Just going to the supermarket you could slide it at the roundabouts. A bit OTT on the road really. The non-LSD version was much less twitchy.

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Malcolm W.
The views expressed in this post are personal opinions and do not represent the views of Safespeed.

That's the thing with comparing 4WD is you need to compare the various types out there.

The original Audi Quattro and most Subarus go for the permanant 50/50 split, though my old Legacy went for a permanent 65/35 split favouring the rear and some have manual or electronic torque distribution.

Most transverse engine 4WD cars such as the Audi TT or Nissan Pulsar GTi-R will be FWD most of the time delivering up to 50% of the torque to the rear when it thinks it needs it.

With a north-south layout you're likely to find the 4WD favouring the rear most of the time, and delivering torque to the front when it needs it.

An oddball one is the E-4WD system found in the Nissan Cube. This is a FWD layout with the rear wheels driven by an electric motor if the system detects that 4WD is needed which is a good idea for implementing the Audi TT style system without the need for a propshaft or centre diff, thus increasing the load area.

So far I've only driven the first two systems in that list, and I much prefer the 65/35 rear biassed 4WD to the Audi TT style. I'll get back to you when my new car arrives and I get to try #3 in the list

I'm not sure I'd agree that FWD was necessarily cheaper / easier to package. With the RWD layout, you get to spread the components out over a great deal more space. It more or less dictates a North-South engine package which gives huge freedom for a decent front suspension design too. The downside (at least with the front engine-rear drive package) is that it's hard to get a decent engine position and a decent steering rack position. You either end up with the rack in front of the engine (not particuarly good for crashworthiness) or you end up with a very high engine, or you end up with some sort of steering box. A transverse FWD arrangement also give other crashworthiness advantages - partly by putting a very substantial wall of somethign very solid between you and anything you might crash into forwards and partly by reducing the weight of the vehicle as it hits the wall. In other words, when the engine / gearbox / diff / driveshaft assembly hits the wall and stops, the remained of the car that still crumpling itself into the wall is a good deal lighter. With the opposite (something like a 911, say), the engine / transaxle is still trying to "roger" you as you hit the wall!

I also think that the chassis engineers who can make small FWD hatchbacks handle are true magicians! As a "yoof" me and a few mates used to enjoy "wheelbarrowing" another lad's Fiesta round into the school bike sheds for a laugh. It really brings home the point that the chassis engineers have to come up with a design that can cope with HUGE changes in weight from unladen to fully-laden on the rear axle and still make the car ride and handle. Even worse, they're the poor sods who have no money to spend on that sort of car compared to a big executive barge or a sports car!

I think that the advent of decent, relatively cheap traction control systems might make RWD a more attractive proposition for the mass market in the next few years. Certainly, I prefer the "pure" steering feel of a RWD. The vicious torque-steer of my current FWD car is what spoils it for me more than anything else. Evening out tyre wear is another plus!

As for AWD, I have little experience of them. A mate who wrks in chassis design once came up with a lovely turn of phrase "they just understeer at both ends"! But maybe that's a bit cruel!

RWD with switchable traction control for me.

Excellent description.

Mind you they will be doing this with either a smaller bend radius or faster than F/RWD.

It makes them good rally cars but not necessarily good road cars.

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Driving fast is for a particular time and place, I can do it I just only do it occasionally because I am a gentleman.
- James May

Interesting set of comments!

My current A4 is the MkIII (56-plate, B7 platform) model which uses a Torsen centre diff set up by default for a 60/40 split to the rear. However it can send up to 90% of power to one axle by means of an actuator (linked to the ECU and ESP system).

My previous A4 (the MkII, 52-plate B6 platform) was set up for a 50/50 split. This handled much like a FWD car but with the understeer taken out and more grip (especially in the wet). Push it too hard and you'd get understeer. The MkIII handles much more like a RWD car, even to the extent that you can get the tail out when pushed hard enough. (Trust me on this!)

The FWD version of my A4 is twitchy, that's for sure!

Another thing, slightly related... there seems to be confusion between the terms "4WD" and "AWD" (not on here but on some other forums). My understanding now is this:

4WD (4-wheel drive) - two wheels permanently driven, drive can be engaged to other axle when required, either mechanically (eg Land Rover) or electronically (eg Haldex clutch on Audi A3, TT, VW Golf).

AWD (all-wheel drive) - both axles (hence all 4 wheels) driven permanently, some form of diff in the centre such as a Torsen, used on Audi A4 upwards amongst others.

Having driven both (Haldex and Torsen) there's advantages to both systems. The Haldex system is lighter and only sends power to the normally non-driving axle when needed, hence uses less fuel. However it's a reactive system which can only stop a slide once it's started.

The Torsen system, although somewhat heavier, offers far better performance as it'll stop you getting into a slide in the first place. Having taken my Torsen-equipped A4 around a test track (not on a public road, don't worry!) to find its limits I could feel the torque shift whilst throwing it around bends at speeds that would make a FWD understeer off the track (and no doubt a RWD spin backwards off the track), the Quattro system just held on. The Torsen was stabilising the car mechanically without requiring any intervention from the ESP.

Other tests I did on the car that day:

Simulated lane change on a "motorway" at 130mph. Basically lanes marked out motorway style on a huge expanse of concrete and a polystyrene block placed to represent the position of a car. Drive past a cone by the side of the track and change lanes at this point. Most cars coped ok with this in the dry... but now spray water all over the track and try again.

The Quattro took it across 2 "lanes" at over 130mph without even flinching.

I think this is a variant of the "elk test" which the original A-class failed spectacularly.

Then there's the "drive in circles on a wet track" test. 70mph at full right lock in 3rd gear and no twitch on a soaking wet track. The organisers reckoned I'd need to top 100mph to be able to break the back end away - and advised me not to try it as if it did lose it at that speed I'd end up doing a full 360 and they weren't sure there'd be enough run-off for me to be able to stop at that speed! This was a standard porous tarmac surface that had been sprayed with water, I suspect if it had been a special low-friction surface I'd have been able to get a nice slide at 30-40mph.

The big problem of course with driving a car with this performance envelope is that you forget just how much better than the average Mondeo it is. Or even the standard A4 - when mine goes in for a service and I get one of the garage's FWD A4s as a courtesy car I'm always surprised by just how much understeer there is. And having to remember of course that no, I can't take this next bend at 60mph like I can in mine, I need to back off to about 35-40mph otherwise I'll be mating with a hedge!

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Magistrates rule #1: "Never let justice get in the way of a conviction."