4 wheel drive & the real world
Discussion
nickfrog said:
Scuffers said:
nickfrog said:
doogz said:
Alternatively, 4WD is safer, as they'll stop at the same rate as a 2WD car travelling at the same speed, but will retain more control over the attitude and direction of the car and will be better equipped to steer around whatever obstacle may present itself.
Off the throttle I don't know if a 4wd keeps "distributing" engine braking through 4 wheels so as to optimise available traction but the brakes would absorb most of that available longitudinal adhesion anyway, up to the ABS trigger point so I don't how much more control you would have.one of the benefits of proper ones with centre diffs that are lockable is that by locking the centre diff, you have effectively linked the front and rear brakes, so makes locking individual wheels harder (and in the dry, transfers a fair bit of the fronts brake capacity to the rears)
even less likely to happen on a duel clutch haldex car as engine braking is reduced a fair bit on duel clutch cars
nickfrog said:
This is good too RWD and winter tyres VS 4WD and summer tyres on snow http://www.youtube.com/watch?v=STaximkaQxo
So much for the superiority of 4wd on snow although obviously 4wd+winters would be the perfect belt and braces snow/ice/cold solution. Farcical in most of the UK IMO.
and an RS4 with winters would have done a mid 5s 60 So much for the superiority of 4wd on snow although obviously 4wd+winters would be the perfect belt and braces snow/ice/cold solution. Farcical in most of the UK IMO.
Pixelpeep said:
ok, i'm liking what i am hearing so far..
this is going to be an odd question and there are tons of variables i understand. but..
on a wet road, slight incline t junction, pulling out and doing a right in a steady flow of both direction traffic what is likely to give me more traction
my current FWD mapped astra VXR (old shape with no LSD)
or
a BMW m135i
(considering same makes of tyre, same condition of car, same driver etc)
I'm guessing the BMW. I'd be inclined to press the DTC - or "direct to cock" as Mrs Puff calls it - button to allow a bit of wheel spin, however I wouldn't turn it all the way off. this is going to be an odd question and there are tons of variables i understand. but..
on a wet road, slight incline t junction, pulling out and doing a right in a steady flow of both direction traffic what is likely to give me more traction
my current FWD mapped astra VXR (old shape with no LSD)
or
a BMW m135i
(considering same makes of tyre, same condition of car, same driver etc)
creampuff said:
I'm guessing the BMW. I'd be inclined to press the DTC - or "direct to cock" as Mrs Puff calls it - button to allow a bit of wheel spin, however I wouldn't turn it all the way off.
Interesting coin of phrase, Mrs Peep (and not bow) has vito'd the BMW, using the term cock also. She has offered up the new 300hp Audi S3 in the 5 door sportback configuration - i think that's a good shout, much better on fuel than the RS3 and noticeably cheaper than the A45. Just trying to get a weekend where we are both free so we can get a test drive booked.
Scuffers said:
sleep envy said:
And you're deliberately missing the point, why would someone want to be going faster in poor conditions on the road?
maybe because they want to go faster than 0Mph?'faster' does not mean 'speeding', it's a relative term
If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
There is a decent video at the top of this page which shows you how the Porsche system works:
http://www.porsche.com/uk/models/911/911-carrera-4...
I love how they do the 3d fly throughs of the car like that.
sleep envy said:
Scuffers said:
sleep envy said:
And you're deliberately missing the point, why would someone want to be going faster in poor conditions on the road?
maybe because they want to go faster than 0Mph?'faster' does not mean 'speeding', it's a relative term
If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
sleep envy said:
Indeed, it's a speed limit not a target.
If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
Maybe its the ability to get to that desired speed without the flashing lights on your dash causing an epileptic fit?If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
Snowboy said:
I have a fwd, a full time 4x4 and a rwd that can also be 4x4.
They are all equally safe in normal conditions if driven sensibly in a sensible manner for that car.
In inclement weather I'd rather be in the full time 4x4.
Snap. Just come over the Cat, it's snow and blizzards and there's a jackknifed lorry and Corolla in a ditch. At one time the road was closed by police and lorries were just ignoring the sign so at lunch the whole road was blocked Buxton side. I went on backroads in a 4x4 and it was deserted. They are all equally safe in normal conditions if driven sensibly in a sensible manner for that car.
In inclement weather I'd rather be in the full time 4x4.
Snowboy said:
....
In inclement weather I'd rather be in the full time 4x4.
And, let's face it, that seems to for a large part of the year.In inclement weather I'd rather be in the full time 4x4.
I learned the hard way I couldn't accelerate off a wet roundabout anywhere near as hard in the wife's MR2 as I could in my GTO.
The first time I took my GTO to Brands Hatch I was passing loads of Porsches; not because the GTO was faster but because the track was damp and they were spinning off. I also drove the GTO all year round (provided the snow didn't exceed the 7cm ground clearance) and never had a slide or spin.
I really wish my Jeep SRT8 had a 4WD selector instead of an electronic one which waits until the rear wheels spin or slide. Even in over 2 tonnes, 420 bhp to the rears is not good when it's wet; worse on packed snow.
driverrob said:
I really wish my Jeep SRT8 had a 4WD selector instead of an electronic one which waits until the rear wheels spin or slide. Even in over 2 tonnes, 420 bhp to the rears is not good when it's wet; worse on packed snow.
I actually used to love that!it would let the back spin just enough to get it sideways before the front pulled in so you could keep it drifting without it spinning round on you!
sleep envy said:
Indeed, it's a speed limit not a target.
If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
There are times when you may wish to accelerate quite hard, like pulling out of a poor visibility junction. Your target speed may be lower than the sign on the road, but that doesn't stop you wanting to reach that speed briskly.If you are travelling at a certain speed which you deem sensible in a 2wd car, irrespective of the number on the speedo or the sign on the road, why would you want to go faster?
You've already determined that your current speed is appropriate for the conditions.
The only car I've lost control of and slid straight over a cross-roads junction on snow in was AWD.
Some of Goldblum's friends must have seriously fast cars because I overtake in the wet all the time in the 4.5 Cerbera and don't have any trouble with wheelspin. Maybe it's my driving godliness though because it's got enough power that you simply don't need WOT for overtaking unless you're sticking with 4th or 5th gear or you're trying to overtake in gaps which aren't safe for overtaking and you're hammering it in low gears. It wont spin wheels in the wet in 4th or 5th gear, and it won't spin it's wheels in 3rd gear in the wet unless you are clumsy changing gear or reach the top 3rd of the RPM range where you're at automatic court appearance speeds.
In response to a mention of a diesel S-Type above, it's interesting because I've heard that a lot, but my 3.0 petrol auto S-Type has been with me for 5 years now and until this winter served me daily on P-Zero Assymetricos. It couldn't be driven with the carefree abandon of a Defender on chunky tyres, but it's never given me any trouble in snow.
Some of Goldblum's friends must have seriously fast cars because I overtake in the wet all the time in the 4.5 Cerbera and don't have any trouble with wheelspin. Maybe it's my driving godliness though because it's got enough power that you simply don't need WOT for overtaking unless you're sticking with 4th or 5th gear or you're trying to overtake in gaps which aren't safe for overtaking and you're hammering it in low gears. It wont spin wheels in the wet in 4th or 5th gear, and it won't spin it's wheels in 3rd gear in the wet unless you are clumsy changing gear or reach the top 3rd of the RPM range where you're at automatic court appearance speeds.
In response to a mention of a diesel S-Type above, it's interesting because I've heard that a lot, but my 3.0 petrol auto S-Type has been with me for 5 years now and until this winter served me daily on P-Zero Assymetricos. It couldn't be driven with the carefree abandon of a Defender on chunky tyres, but it's never given me any trouble in snow.
jamieduff1981 said:
The only car I've lost control of and slid straight over a cross-roads junction on snow in was AWD.
Some of Goldblum's friends must have seriously fast cars because I overtake in the wet all the time in the 4.5 Cerbera and don't have any trouble with wheelspin. Maybe it's my driving godliness though because it's got enough power that you simply don't need WOT for overtaking unless you're sticking with 4th or 5th gear or you're trying to overtake in gaps which aren't safe for overtaking and you're hammering it in low gears. It wont spin wheels in the wet in 4th or 5th gear, and it won't spin it's wheels in 3rd gear in the wet unless you are clumsy changing gear or reach the top 3rd of the RPM range where you're at automatic court appearance speeds.
You know what - you're right. The whole premise of fast AWD/4x4s is flawed. Despite billions of pounds of sales the world over, the popularity of WRC and it's lesser brethren, the entire soft roader market etc etc. Because you can drive a 4.5 Cerbera without wheelspin in all conditions. I'm surprised the rest of the world hasn't discovered this nippy little all weather sportscar and sales haven't rocketed.Some of Goldblum's friends must have seriously fast cars because I overtake in the wet all the time in the 4.5 Cerbera and don't have any trouble with wheelspin. Maybe it's my driving godliness though because it's got enough power that you simply don't need WOT for overtaking unless you're sticking with 4th or 5th gear or you're trying to overtake in gaps which aren't safe for overtaking and you're hammering it in low gears. It wont spin wheels in the wet in 4th or 5th gear, and it won't spin it's wheels in 3rd gear in the wet unless you are clumsy changing gear or reach the top 3rd of the RPM range where you're at automatic court appearance speeds.
Or perhaps they've just used a bit of common sense and realised there are other options available more suited to poor road conditions.
As for me - my AMG doesn't like snow and rain up here too much despite the Conti winters so like many others I have alternate 4x4 transport.
Silly me, I should have bought a Cerbera instead.
jamieduff1981 said:
In response to a mention of a diesel S-Type above, it's interesting because I've heard that a lot, but my 3.0 petrol auto S-Type has been with me for 5 years now and until this winter served me daily on P-Zero Assymetricos. It couldn't be driven with the carefree abandon of a Defender on chunky tyres, but it's never given me any trouble in snow.
I think the important word here is petrol! I think the turbo diesel spools up & spins the rear wheels up & that seemed to be the issue. I've driven loads of stuff in snow & the Jag wasn't going anywhere.Gassing Station | Advanced Driving | Top of Page | What's New | My Stuff