I was watching an episode of “Keeping Up Appearences” from series two and Richard, Hyacinth and Mrs Fortescue are in the car. Mrs Fortescue says “How fast is he driving”? Hyacinth leans over to see the speedometer and replies “Only 28 miles per hour”
I thought England was all metric? Is this an error in script? Or do the speedometers in England have both mph and kph?
Speedometers are marked in mph and kph. Speed limit signs are in mph, and distances on road signs are in miles, yards or feet.
Obligatory nit-pick: this applies to the whole of the UK, not just England 
Nope, mostly metric is more like it. Some remnants of the imperial system live on. We buy petrol (gasoline) in litres, but measure fuel consumption in miles per gallon. Distances are in miles, body weight and other bodily measurements are more often stated in imperial units in informal usage, and foodstuffs such as milk and beer are often measured in pints (British pints, that is, not those puny American pints ;)).
Britain is officially metric but unofficially remains traditionally English in a lot of ways. This is the country that has raucous parliamentary debates about the proper amount of foam in a pint (not 470ml) of beer, after all.
Yes, we use miles, miles per hour, and miles per gallon.
A few years ago, I was in a technical seminar in Toronto. I had some technical questions for a consultant. Fishing for more information, he kept asking me about measurements. naturally in answered in English units such as inches, pounds. He starts complaining about America not being metric like the rest of the world.
We went to dinner. Naturally he ordered a 16 oz rib-eye steak. I asked why he did not order a ~450 gram steak?
Was one on the menu?
And we order beer in [British, 20 oz] pints. Metric is definitely more prevalent in Canada than in the UK, but we still hold on to the Imperial system for people’s height and weight; our driver’s licenses list our height in metric, but most of us still use feet and inches when asked. I think our building codes are even stated in Imperial, although they probably include metric as well. Sunspace can no doubt confirm whether that’s still true. Heck, even Japan uses inches for marketing televisions (no doubt because of the American market influence).
Clearly you meant to write 568ml. A litre of water’s a pint and three quarters.
Anecdote alert: On Ramsay’s Kitchen Nightmares he is all over the UK going to local markets and all of the local meat and produce is sold by the pound. I always get confused when they talk about “5 pounds per pound”. 
He said “NOT 470ml”.
Oh, I think I was wooshed.
Gotta relay one of my favorite stories of traveling to the UK. I was all nervous the first time about driving on the left, but found that to be not so difficult at all. I got myself on the M4, and figured I’d go at a safe speed to start. I figured 100 kph would be about right, so I ripped her up to 100 and found I was flying by everyone else. Then I realized… oh, they’re not metric on speed here. Oops!
I once saw the opposite in Ireland, with a car with German plates doing 60 kph on the motorway. I’ve heard that Ireland has since switched to metric speed limits, though (they were already in the process of changing over distances on signs, when I was there).
Just as a note, Canadian cars have mph and kph on the speedometers as well. The kph is in bigger letters and on top, mph small and underneath.
As usual, the Canadians have it backwards! 
As somebody once explained to me, “Britain is going metric inch by inch”.
Heck, the companies that BUILD buildings use imperial. I have seen the engineering and drafting departments of at least 35 building firms in Canada and not a single one of them used metric to describe the parts of a building.
It’s just too well established in that particular field, I guess.
In that case, I wonder whether it is true that metric is more prevalent in Canada than in the UK, because here almost all measurements in official or professional documents, such as building codes or architectural drawings, are metric.
Civil and permanent-way engineers on the UK railway system still use miles and chains when measuring distances on the railway network.
But even they use mixed units. Here are two example from this month’s Modern Railways magazine:-
The No. 4 Up platform extended by 38 metres.
Former Bentley Colliery South crossover at 154M 43 ch, taken out of use, pending removal,
One of my magazines talked about a fellow buying steel tubing from an iron monger:
“Is that 2 inch tube?”
“No, 51mm, How many feet did you want?”