Currently driving a rental car as mines off the road after an accident. Been given a 58 plate Ford. Already the bonnet is rusting (i assume after a stone chip).

I remember old Fords always used to rust but it appears nothings changed on modern ones. Anyone know why though - surely its galvanised same as any other car? Never had any rusting problems on previous cars (Renaults and Peugeots) even after various stone chips and accident damage.

Shame because its a really good car to drive but I think the rusting problem would put me off buying one. Read more

Car losses power under load especially uphill, i have changed the plugs and air filter still no better. Where is the fuel filter on this car so i can elliminate it as a possable cause. The car has been sitting in my drive unused for 1 year, would this have an impact on the performance. I have had the exhaust checked out at ATS and its ok, what should i do next, thanks. Read more

Good day for Britain in the Tour de France.

Mark Cavendish won the stage in Paris making his fifth stage win and a new British record.

Bradley Wiggins came fourth overall and another British best.

Congratulations to them both.

I realise this isn't strictly motoring related, but could the Mods let it run to see if it has legs? Read more

I am wanting to find out from the DVLA when I bought and sold my old Polo. I need some documents to prove I bought it at a certain time, but unfortunately all I remember is that it was an A reg Polo and the DVLA said they need the license plate numbers.
Any ideas on where I could get the information - if its possible?
Thanks
Tam

Made vehicle non-specific Read more

Watching Top Gear the other night, an oft repeated bit of "wisdom" was trotted out which reinforces a significant misunderstanding of how cars work. I can see why people believe it; on a superficial level, it makes sense; however, it's quite bogus.

The "wisdom" is;

On a front wheel drive car, the front wheels do more work because they are both steering and driving

This is, despite being so deeply ingrained as received wisdom, utter nonsense.

To expose this as the bunkum it is, consider a car with a 50 / 50 weight distribution going round a corner at reasonable speed, and with neutral throttle. To simplify matters, imagine the the height of the centre of gravity is so low that weight transfer to the outside is negligible.

How much side force is generated by the front wheels compared with how much is generated by the rear?

If you believe in Clarkson's maxim, you'll have to say that the front, steered, wheels are doing more work, producing more force. However, if this were the case, there would be an unbalanced moment acting on the car, tending to make it spin (front end into the centre of the corner, back end out!).

Of course, what actually must happen for equilibrium is that front and rear wheels must produce the same amount of side force. This would remain true if the car had four wheel steering, or even rear wheel steering.

To say this bluntly;

Just because a wheel may be turned relative to the car's body does not mean it is producing more or less sideforce than the wheels which remain inline.


Now, having got that off my chest, it's possible to talk a bit more about what really affects how much work tyres have to do. The thing which really dominates here is weight distribution. Had I dealt with an example of a car with a 70 / 30 weight distribution, then, yes, the front wheels will be producing more sideforce than the rear, surprise surprise, in the ratio 70 / 30!!

IF we temporarily begin to think about the 50 / 50 car and consider what happens if you add drive or brake forces, you'll see there's no black magic here either. The brake or drive forces act at approximately right angles to the sideforce, and together form a resultant force, so as the sideforces were equal front to rear, if you now clumsily add some drive force to the front wheels, the resultant force will now be larger than that of the rear axle, and you'll begin to get more slip from the front tyres - a power on understeer effect. If you do this to the rear wheels, you get some power on oversteer effect. Again, none of this has anything to do with which wheels are turned relative to the car body.

As an antedote to obtaining vehicle dynamics misinformation from messrs Clarkson, Hammond and May, I would like (again!) to recommend "Fundamentals of Vehicle Dynamics" by Gillespie. It's an expensive book, so, perhaps best to ask your library to get it in for you. Read more