Very strong winds again today where I live. Was doing about 80 on the way to work and the cross winds were making the car wobble. Nowhere near losing control or anything but got me wondering whether the spoiler on the back of the car was actually doing anything to keep me stuck to the road.

Spoilers seem standard across the range since the mk2 is it just there for looks?

just for looks, spoilers or wings don't help much with crosswinds. even F1 cars and planes suffer from crosswinds and turbulence

they look good but at the speeds you should be doing the down force generated is meaningless.

even at higher speeds the design of it isn't to gain any more downforce, the RS spoiler looks like its been given some more consideration tho.

Something it might do however is help remove drag, if air is allowed to flow over the car without any consideration it can create a vortex behind it, think of it like eddies spinning around your tail gate, this could increase drag but again you probably need specialist gear to ever notice the difference, that's why driving around with a broken rear window can be deadly as car fumes can get drawn in to the car.

Its kinda cool the way air works, but for our normal focus, youll not see anything significant with downforce, reduction in drag is about as good as any of the car styling will give.

makes them look good

Speed generates lift ( airflow under the car ) & the higher the speed the greater the lift, so when driving in crosswinds, that invariably destabilise a vehicle, simply reduce roadspeed which will reduce the lift effect & the car will become more stable.

Rear spoilers on everday cars have little to no effect at less than F1 speeds.

Also when considering cross winds, think about the size of the spoiler, vs the size of the side of the car.

The bigger the side profile of the car, the bigger the "sail" you have being pushed by the wind.

This is why they stop high sided vehicles crossing certain bridges on windy days.

The answer is yes and no. Yes because cars with a properly designed spoilers create downforce to push the car down to the tarmac ie f1 and other race cars. No because most road going cars are designed with looks in mind not downforce and you should never really reach a speed that will create downforce. The same goes for the rear diffusers that are now on most sporty models. But a spoiler or diffuser will never have any affect when it comes to cross winds.

in fact nearly every modern car has a "spoiler" its primary reason is for the hi level brake light to be mounted in

Thanks for the responses. It's confirmed my suspicions that in this case they're primarily for styling purposes.

Are Hi level brake lights compulsory now then?

Thanks for the responses. It's confirmed my suspicions that in this case they're primarily for styling purposes.

Are Hi level brake lights compulsory now then?

C.H.M.S.L.'s have been a legal requirement in Europe & the U.K. since 1998 i.i.r.c.

They don't have to be mounted in a roof level '' spoiler '' - just higher than the o/s/r & n/s/r brake lamps

I can see why they need to be a legal requirement, when morons are driving around with both brake bulbs out...

This is the only time I like the ~12 tonne weight of the Focus... Crosswinds in tiny, cheap, superminis are horrible!

Spoilers on 'normal' cars are just for looks though as above. Not sure why but they do make a big difference aesthetically compared to identical non-spoilered cars!

I drove a 3 wheel reliant once you will note I said once never again that in a cross wind is a truly terrifying experience but spoilers really are aesthetic on most cars

I drove a 3 wheel reliant once you will note I said once never again that in a cross wind is a truly terrifying experience but spoilers really are aesthetic on most cars

Inherently unstable fibre glass & gaffa tape death traps :(

My Auntie had a reliant regal back hundreds of years ago in the 70`s, they did test your bottle..auntie was a HGV driver!! could of had any car she wanted

Death Trap....no truer word...;)

I can see why they need to be a legal requirement, when morons are driving around with both brake bulbs out...

very common practise and most annoying just lazy owners who don't give a damn

No use at all because they create downforce on the rear and they are front wheel drive. Waaaaaa

ive started pulling up along side folk with broken tail lights or brake lights when I get to a junction then try and wave their attention, what bugs me the most is that most folk, already know and its "on the list" a large number of others look at me like I've grown horns, a few seem to accept the suggestion of getting them fixed

The faster you go the more lift you get so doing 80 in crosswinds like we're having not a good combo with a spoiler that does diddly squat, maybe slow down a bit and you wont get a wobble

ive started pulling up along side folk with broken tail lights or brake lights when I get to a junction then try and wave their attention, what bugs me the most is that most folk, already know and its "on the list" a large number of others look at me like I've grown horns, a few seem to accept the suggestion of getting them fixed

Some kind soul did that to me when my brake light was out. I had no idea as my car is too old to tell me when a bulb has blown. I was very grateful (although did get a second stranger to confirm it in a carpark just in case the first was pulling a prank) and then went to the nearest halfrauds to get a set of replacement bulbs. I always try to let other know if I can pull up alongside them at a junction too.

Some kind soul did that to me when my brake light was out. I had no idea as my car is too old to tell me when a bulb has blown. I was very grateful (although did get a second stranger to confirm it in a carpark just in case the first was pulling a prank) and then went to the nearest halfrauds to get a set of replacement bulbs. I always try to let other know if I can pull up alongside them at a junction too.

Even in 2008 tight Ford didn't bother will bulb failure warnings on the Focus... So I know when the boots open or when the screen wash has run out...but not the things I can't check myself like brake bulbs!!

Vauxhalls had it 10 years earlier!

The 3rd lamp makes a huge difference, probably one of the only good laws to come out of the EU, have seen a couple of cars this morning where the brake lights hardly made any difference with their tail lights on. Id have thought that would be part of the MOT, not just working but significantly brighter than the tail lights

When I was (much) younger my mate had a Bond Bug. Now that was 'fun' to drive even when there was only a breeze, let alone real wind. :-)

Part of the issue there is people driving around with rear fogs on when it's not foggy (seems to be a lot of this lately round here). Makes it much harder to see brake lights.