80 Miles Per Hour on British motorways?

[Raging_Bulls]

A wise man once said : "Speed never killed anyone. Suddenly becoming stationary, that's what gets you"

Joking aside, I'm all for variable speed limits. There's nothing dangerous about doing 100+ on an empty motorway. However in rush hour traffic lower speeds make sense.

Put cameras every half mile to measure the amount of traffic and adjust the legal maximum speed accordingly. Digital signs can be used to show the legal limit in that area.
The same cameras can be used to catch speeders as well.

 

[Fudd]

As wind resistance goes up with the cube of speed, a 14% increase in speed increases wind drag by 50%.

Regardless of how efficient your engine is, that has to be paid for with fuel.

Are you really saying that you get better fuel consumption at 80mph than 55? And motorbikes are at their most economical at 160???

The point of gears is to match engine efficiency to speed. :roll:

Obviously when you take drag into account it throws another significant variable in to the mix but thats the point I'm making - you can't just say all cars are x% less economical at 80mph as all cars are different; Different gearing, different engines, different air pressure in the tyres etc. Its a bit like saying 'a car' takes a certain distance to stop from 70mph..... Its BS.....

I have a gsxr750 and if i do my local loop at an average speed of around 100mph i arrive home with some fuel still in the tank. 120-130mph and i have to stop on the way home
Not that i'd ever ride at those speeds as apparently there's a law against it

130mph average on open roads on a 750 road bike? You want to go to the IOM TT and start racing. That pace on closed roads and race machinery should destroy the 131.57mph lap record

 

[highlandsflyer]

As wind resistance goes up with the cube of speed, a 14% increase in speed increases wind drag by 50%.

Regardless of how efficient your engine is, that has to be paid for with fuel.

Are you really saying that you get better fuel consumption at 80mph than 55? And motorbikes are at their most economical at 160???

The point of gears is to match engine efficiency to speed. :roll:

Obviously when you take drag into account it throws another significant variable in to the mix but thats the point I'm making - you can't just say all cars are x% less economical at 80mph as all cars are different; Different gearing, different engines, different air pressure in the tyres etc. Its a bit like saying 'a car' takes a certain distance to stop from 70mph..... Its BS.....

I have a gsxr750 and if i do my local loop at an average speed of around 100mph i arrive home with some fuel still in the tank. 120-130mph and i have to stop on the way home
Not that i'd ever ride at those speeds as apparently there's a law against it

130mph average on open roads on a 750 road bike? You want to go to the IOM TT and start racing. That pace on closed roads and race machinery should destroy the 131.57mph lap record

I realised you were getting at the broadness of the statement about decreased mpg, but I guess like any average it took into account all sorts of vehicles.

As far as anyone averaging even 100 on public roads, well I live in the Highlands and can average some nice pace, but even my pals in South Africa would struggle to average more than 100 on their long straight roads.

 

[FSR-Si]

at the HGV haters, one of the reasons they overtake is to keep the momentum going, it takes an awful lot of fuel to run a fully freighted truck so when the truck loses momentum its fuel consumption can go to pot whilst trying to regain its speed, Fuel consumption on an artic averages 9mpg so when that truck loses its speed and tries to regain it it can go as low as 5mpg putting up the price of transporting "our" stuff about. Trust me the drivers dont like slowing you down either.
As a for instance our company have isotrak tracking systems fitted and monitor our fuel consumption/braking/tickover time etc, If we dip into the red for uneconomical driving 3 times we have to have retraining, if we still cant reach the companies expected targets we get the boot, then in the next breath our bosses are telling us we must keep to our schedules.

So please just have a little patience with us we're not all perfect road users

 

[FluffyChicken]

I understand the reasons, but a little more thinking ahead from the truck drivers might help the cause.
I'd rather pay more than be dead.


of course there are plenty of nice truck drivers it's the one's causing the swerving, 20mph suddenly breaking when there are no lanes for people to move to 'suddenly' that are the problem.

 

[FSR-Si]

of course there are plenty of nice truck drivers it's the one's causing the swerving, 20mph suddenly breaking when there are no lanes for people to move to 'suddenly' that are the problem.

Yup i'll agree to that! And then from our point of view theres the person in the car that screams down the motorway then swoops across 3 lanes of traffic and stamps on the brakes just so he/she can get up the slip road before having to wait for a respectable gap behind the slow truck.
For me this arguement will go on for ever, best thing they could do in my opinion is make all vehicles have the same speed limit, bring everybody into line at 60mph.

 

[gibbleking]

i like to sit behind the lorries in the far left doing a nice 55 and saving on fuel as the lorry does all the hard work....i drive a fast car but it is something i wont do simply because id rather get to where im going alive and ten minutes late...

 

[David B]

A wise man once said : "Speed never killed anyone. Suddenly becoming stationary, that's what gets you"

I wasn't aware that a wise man had said that. I have, however, heard it attributed to a certain supermarket denim-clad Sunday Times columnist with Brillo-pad hair.

David

 

[Dr S]

Joking aside, I'm all for variable speed limits. There's nothing dangerous about doing 100+ on an empty motorway.

Really? Never had a blow out or a suspension failure then I take it?

I spent a good few years driving between very large trees on gravel at 100mph plus, and found it pretty easy until something broke. You are just a passenger from that point on. Now a motorway is much safer than the blind crests, car size ditches and stout trees of Kielder, but still pretty scary in a high speed spin or roll over.

As i said earlier in this thread, speed is not a killer in the right hands. Its driving standards that kill- I see plenty of drivers struggle to park in a car park space let alone handle a car at 100mph when a tyre goes.

Cars are so capable these days. I drove a nice Porsche a few weeks back and thought it didn't feel very fast. A glance at the speedo confirmed i was going rather fast indeed. My point is that modern cars lull you into a false state and encourage people to drive way beyond their personal limits. My guess this is a very large contributing factor to many many accidents.

 

[orange71]

Yes - try driving a Series 3 Land Rover at 60mph - that gives you a real impression of your speed - you really wouldn't want to go faster :shock: