I'm back!
Wasn't that terrific? What a fantastic response! I loved it. I'm still giggling. I have read all the responses and I'm no sure where best to fit in the reply!
I fancy that all the stuff that Michael was talking about realy applies to the sort of cars that Top Gear reviews. You know, fast twitchy cars, loads more horse power than I could ever afford and indeed would ever want to buy.
Yeah, I'm sure that for fast cornerning at 90 mph, with only 3 wheels on the ground going around the hammer head corner on that aerodrome, 8mm of treat on the back, 6mm on the front, just the sort of track driving that Top Gear shows when visitors to the programme drive the 'ordinary' car as fast as they can, then that is the right thing to do. Under those conditions (not that I would know) I could imagine that a back going before a front would be more scary that a front going before the back.
Forget all that. Its hyperthetical bollocks for us guys. We all here, except you may be, drive on public roads where we try and stop before we run into pedestrians and other unpredictable obstructions that suddenly appear in front of us with out our permission!
I drive my car on either narrow country lanes, or 'straight line' A roads & motorways.
On a country lane, in the wet (3 inch deep puddles made of cow shit and fallen leaves), and the near side has inch deep loose road surface chippings that have piled up over the summer, I need to stop damn quick when someone comes the other way who hasn't learnt what the middle peddel is for yet, and where I live there is a shicane! Yeap, a real schicane! Its amazing. No priority signs; a blind bend lead up to it one side and a dead end dive hole the other. The road narrows to 8 feet. So you are approaching this 8 ft gap at 30-35 MPG, (if you drive at 25 MPH you can't get out of the shicane before someone coming the other way crashes into you ) you see someone appear around the bend coming the way, you have to either go or stop. If you stop you need to stop in the 'lay bye' before you hit the 3ft diameter oak in the middle of your path. You have got 8mm of tread on the back, and 2mm on the front. Its pissing down with rain, there is flood water running down the road, and the cows have recently gone across the road for milking (shit everywhere). And you are more confident of straight line stopping with your this configuration rather than having 2mm on the back and 8mm on the front? If so, then please don't drive near where I live!
Put this scenareo in front of your tyre manufacturer experts and see what they say!
The other time when you NEED tread is when you are on a long drive, doing 70 MPH, tried, fed up, pissing down with rain, thinking about .................., then there is a pile of red stop lights in front of you! Again you, Michael, are more confident of straight line stopping with this tyre configuration than having 2mm on the back and 8mm on the front? If so, then please don't drive behind me when I am on a motorway in the wet.
And why didn't you understand my comment about a front engine car sinking front first in a lake? I didn't explain it as I thought that I would be patronising! However, the point is (as you correctly alluded to), front engine cars are heavy in the front. (Focus news group, I assume we are talking about front engined cars here are we?). When any car breaks heavily most of the weight 'transferes' to the front. With a front engined car there is vertually no weight on the rear and therefore virtually no breaking force given by the rear tyres. Why do you want any treadon the back under these straight line maximum breaking conditions in the worst weather? You don't, but you do when whizzing around corners quick, especially if the car heals over so much the offside rear tyre is off the ground!
So its all a matter what you use your car for. Racing, or trying to not run over kids that dash out in front of you!
Take my advice chaps, watch the current child safety advert with the kid that is going to be run over cause the car was doing 35 mph rather than 30 mph. The front tyres are locked and smoking, the rears are free and are rotating. Draw your own conclusions about the laws of physics and which tyres need the tread in the wet.
And bear in mind that the Focus cars you see on race tracks are stripped out, different engines, different suspension, different ....... and everthing is balanced, and I bet they don't put tyres with 2mm of tread left back on the car to get another 2000 miles out of them as I do!