Advantages of 4WD on ordinary saloons?

[Norfolkandchance]

Hi,

I am often surprised to see ordinary saloons with four wheel drive and I wonder what the buyer is looking to gain. I'm talking about 320d X drives, for example, but i see it on lots of (mostly German) saloons.

I can see an advantage if you live in somewhere hilly and cold, like the Yorkshire Dales or somewhere, but I don't. I live in Norfolk.

Modern cars have very good traction and stability systems, so 4WD isn't needed to prevent accidental spins exciting damp roundabouts.

The cars aren't particularity powerful. Its not like an M5 where the 4WD may well make it faster because they are traction limited.

They don't have raised ride height and are fitted with ordinary summer tyres so they wouldn't be much better at negotiating a rutted farm track or pulling a horse box out of a field.

So is there something I'm missing. Or have they just fallen for 30 years of marketing? Or is it they want reassurance for the few days per year when there is snow on the ground.

[Norfolkandchance]

rossub said:

Bowlers said:

X Drive BMW suspension always looks higher than RWD variants, so I'm not sure if they have better ground clearance or not?

My RWD 330d went a bit sideways off a roundabout the other week, it's more the torque in these that gets that back out of shape in damp/cold conditions. Personally I prefer it without, less weight and a bit more playful.

Which is the exact reason other people want the added security of all wheel drive. It’s not just for snow. As you said, they can be tail happy in the wet. I wouldn’t enjoy rear wheel drive in the winter at all.

Well, we are opposites then. I like tail happy cars. But I realise that some don't. I once sold an E30 325i to a journalist from Evo who crashed it, apparently due to its tail happyness, on a motorway slip road! However, I'm not talking about a 330d, I'm talking about a 320d. And Audis, where the alternative is FWD and therefore not tail happyness.

[Norfolkandchance]

fido said:

Even a lowly 320D has 280lbft of torque - about the same as a Subaru WRX - and you wouldn't question the AWD on that. Fat rear tyres on on modern saloons make 4WD even more relevant in winter conditions.

I don't question the AWD in the Subaru because the Subaru is a performance car. Designed to go fast. No doubt there are conditions where an X drive 320 would be faster than a RWD one. Not just snow either. greasy day and lots of slow corners, for example. However, the 320d isn't primarily about going fast in the way that a WRX is.

Also the TT compared to M135i - that is an interesting insight. One of the reasons I like 2WD is the fun of giving just not too much power (or "accidentally" giving slightly too much).

Anyway - I think we've got the answer. Rightly or wrongly they perceive that they are safer / easier to drive or more likley to get them home in snow.

Thanks for all the answers. I was intrigued is all.

[Norfolkandchance]

s m said:

Was that Stuart Gallagher by any chance?

No. He was called Steven, I think

[Norfolkandchance]

300bhp/ton said:

Norfolkandchance said:

They don't have raised ride height and are fitted with ordinary summer tyres so they wouldn't be much better at pulling a horse box out of a field.

They would be massively better in this regard.

I have a friend who works as a design engineer for a 4x4 manufacturer, including a spell working with the algorithms that control the traction control for various different types of terrain. Longish wet grass is, according to him, one of the hardest surfaces to get traction on because as soon as the wheels slip it tears up and the tyres become clogged. Apparently more so than other surfaces. He told me that they had had a presentation from a potential supplier, pleased that their new Haldex equivalent could transfer drive to the rear within half a turn of slip from the front. The consensus of the meeting was that half a turn was fine for most surfaces but too late for wet grass.

Having seen a Discovery, with road-biased but still 4x4 tyres, stuck on a virtually level wet grass field, I can very much believe him.

[Norfolkandchance]

lornemalvo said:

Some of the comments in this thread surprise me. I can't believe that anyone other than an uneducated chav would want a "tail happy" car on public roads. I want a car that's planted, even at speed. I don't want to drift, or slide, I just want to make safe progress, sometimes quickly where appropriate.
I've had a two rwd BMWs that were a nightmare in snow, practically undriveable. That was down to simple physics - fat tyres etc, not lack of driving ability. As much as I love the driving feel of RWD BMWs, I'd only buy a 4wd BMW, for occasional snow (hate the thought of being unable to go out), but also for the added confidence in wet conditions, poor road conditions etc

Edited by lornemalvo on Wednesday 10th October 19:29

Well I'm not an "uneducated chav" (nice up-to-date reference, by the way) and I like the extra control that RWD gives, in that I can alter my line as required in certain circumstances when it is safe to do so. I'd rather be going a bit slower but having fun than going fast because of all the AWD grip.

There is enjoyment to be had from getting difficult things right. And we all need to draw the line at what is enjoyable where it is appropriate.

[Norfolkandchance]

Can't you all just leave him alone? He's backed himself into a corner but he's not going to see the light, so its pointless.